39 Decisions... Decisions 03
3.2.5 LINE UP YOUR FINANCING
While you may have identified potential costs and financing options during your preliminary research, once you have developed draft plans for your ADU, you should be able to develop a more accurate assessment of the potential construction costs.
Your cost estimates will vary based on the size, construction methods, site constraints, and material/finishes. When determining how to finance your ADU there are several factors to consider and you are encouraged to assess your personal financial situation and conduct additional research to determine which avenue best suits your needs. The following are some common methods that can be used to finance an ADU:
• Existing Savings - Self-financing your ADU is a quick and easy way to finance your dwelling unit, however, this option may not be available for all homeowners. It also may not be the most beneficial option in the longrun, depending on available loan interest rates and your need to obtain a return on your investment.
• Home Equity Loan - A home equity loan, sometimes referred to as a second mortgage, is a secured loan with a fixed interest rate and repayment plan. This loan works well if you have an exact cost for the construction of your ADU.
• Home Equity Line of Credit - A home equity line of credit can provide funds by borrowing against the existing equity of your home. You can borrow up to a specific limit and then repay funds over time. If you have equity in your home and want the flexibility to borrow and repay as payments to your builder are due, this option may be a good fit for financing an ADU and may have positive tax deductions.
• Construction Loan - A construction loan is a short-term, typically one year loan, that estimates the home value with the addition of an ADU and allows the homeowner to borrow against that amount. But you will need to swing this loan over into a mortgage after construction is complete. • Renovation Loan - The renovation loan is a mortgage loan that helps if there is limited equity on the current property. This loan provides financing for repairs, upgrades, but also requires construction work to be completed in a six month period.
• Cash-out Refinance - With a cash-out refinance, homeowners take on a larger loan and obtain some cash out of the refinancing process.
REVIEWING YOUR ADU PLANS
The plans for your ADU will need to include several
details to be considered complete. This includes
the following from La Mesa’s Plan Review Submittal Checklist:
Site Plan
Floor Plans and Roof Plan
Elevations
Sections
Foundation Plans
Floor and Roof Framing
Plans
Details
Electrical and
Mechanical Plans
Plumbing and Gas Line
Plans
General Building Notes
A link to the Plan Submittal Checklist can be found in the next section.
3.2.3 REVIEW AND REFINE YOUR PROPOSED ADU DESIGN
After taking your goals, site constraints, planning and zoning standards, and building codes into consideration, your designer will draft a set of plans for your ADU. These will include a site plan which will show the location of the ADU on your property and a floor plan which will detail the layout of the interior of your ADU. The plans will also include scaled drawings and details on how the foundation, flooring and roofing, electrical and mechanical, and plumbing and gas lines will be constructed.
You should review these plans carefully to make sure they meet your needs and expectations. Conducting a thorough review of the plans can help to avoid backtracking and reduce delays or other changes that can cost time and money during the construction phase.
3.2.4 COMPLETE CONSTRUCTION DRAWINGS
With your review complete, your designer will incorporate revisions based on your feedback and prepare a set of construction drawings for your ADU. These drawings will ultimately be submitted for Plan Review and can be used to obtain bids from contractors.
La Mesa Accessory Dwelling Unit Guide
40 3.3 PLAN REVIEW AND PERMITTING
At the end of the planning and design process, you will have a set of plans for your ADU that contains all of the information needed to build the project. The next step is to submit these plans to the City and initiate the plan review and permitting process.
This process will involve review and discussions between your designer and City staff to ensure the proposed designs comply with all applicable planning standards and building codes. These steps are detailed in Figure 3-2, and a professional designer should be familiar with these requirements for the City of La Mesa. This is important because it will reduce the likelihood of mistakes or omissions requiring revisions and resubmissions.
In addition, it is important to note that the ADU review process is ministerial rather than discretionary. This essentially means that plans that meet the established, objective design parameters will automatically be approved; and that the reviewer holds no subjective power to approve or deny a project based on their own judgments. The general process from the time an application is submitted to the issuance of a building permit is outlined in this section.
3.3.1 SUBMIT YOUR BUILDING PERMIT APPLICATION
Designers should review and complete the City’s plan submittal checklist to ensure that the plans contain all of the required information and meet layout and format standards set forth by the City.
Plans must meet submittal requirements and pay the applicable fees before the City will consider an application complete and begin reviewing plans. The clock on how quickly the City is obligated to provide a permit starts once your application is considered complete, not just when you first submit. An incomplete package can cause a delay of several weeks and increase your overall costs.
The City of La Mesa utilizes an online plan review and permitting system where customers can generate electronic permit applications; submit plans, supporting documents, reports; receive comments and corrections; re-submit plans; pay fees; and receive permits 100% electronically.
Links to these resources including the Plan Review Submittal Checklist, as well as La Mesa’s Electronic Plan Review Portal are provided to the to the right. Please refer to section 4.6 for specific URLs associated with links provided in these chapters.
PHASE 3: PLAN REVIEW
AND PERMITTING
Key Steps:
Submit your Building Permit
Application
Pay Applicable Permit Fees
Revise and Re-Submit
Drawings
Obtain Your Building Permit
FIND APPLICATIONS
AND INSTRUCTIONS
Plan Review Submittal Checklist
Electronic Plan Review Portal
41 Decisions... Decisions 03
3.3.2 PAY APPLICABLE PERMIT FEES
A fee for the plan review is assessed based on several factors, including but not limited to: floor area size of the proposed ADU; whether or not the ADU will be attached or detached; and whether you will be converting an existing garage, part of an existing primary residence, or existing accessory structure into an ADU. The Building Division can provide a rough estimate for the plan check fee once the required information is provided. Building permit fees are determined during review of the building plans.
Projects that only propose an ADU are exempt from park fees and the first ADU or JADU on a lot is exempt from Regional Transportation Congestion Improvement Program (RTCIP) fees. Additional units are required to pay the applicable impact fees. As an added incentive for homeowners to pursue ADU projects, as of July 1, 2022, the City of La Mesa will waive the first $2,000 of permitting fees associated with ADU or JADU projects.
3.3.3 SUBMIT PLANS
After you submit your plans to the City through the online portal or in person, Building Division staff will review the submission for compliance with applicable codes and regulations. Applications will be reviewed as quickly as possible and will be approved or denied within 60 calendar days. Denied applications will be provided with comments and corrections necessary to achieve approval. A denied application may be reactivated within one year of initial submittal with submission of the necessary corrections.
Other factors on which approval and permitting may depend include input from public works and planning staff, fire department review (particularly if sprinklers are required), possible solar requirements, water and utilities, and potential need for grading, encroachment, and/or right-of-way permits
3.3.4 OBTAIN YOUR BUILDING PERMIT
Applications will be reviewed as quickly as possible and will be approved or denied within 60 days. The application and plans will be approved when all reviews are complete and compliance with applicable codes and regulations has been confirmed. Upon submittal of permit declarations and payment of any outstanding fees, a building permit will be issued.
CITY REVIEW TIMELINE
Applications for a building permit submitted
for ADUs must be approved or denied within 60
calendar days after receiving the application,
if there is an existing dwelling on the lot.
The 60 calendar day time-frame begins once a complete application is submitted and fees are paid and follows the process outlined below.
Submit application and pay fees
City reviews plans and routes to
departments for review
If needed, City issues a comment letter
with necessary revisions
Applicant revises and re-submits drawings
City reviews revised plans to confirm
necessary revisions are addressed
Building permit issued
The estimated time-line for this process assumes no more than two rounds of plan check comments, with approximately 7-10 days per round of review.
Figure 3-2: Plan Review and Permit Process
La Mesa Accessory Dwelling Unit Guide
42 3.4 CONSTRUCTION AND INSPECTION
The next phase of your project is the construction phase. With plans and permits in hand, it is time to begin reaching out to contractors to solicit bids. If you have gone the design/build route you don’t need to find a contractor, as the company will have the in-house resources and experience to carry out the construction themselves.
There are many ways to find reputable builders and contractors. Word of mouth recommendations can be a good way of finding contractors from satisfied clients. Often times, seasoned designers and architects can provide you with recommendations based on past project experience. Customer reviews found online can help refine your recommendations from neighbors and designers.
Contractors must be licensed by the State of California. Contractor licensing information can be obtained from the Contractors State License Board on their website or by calling (800) 321-CSLB.
3.4.1 OBTAIN BIDS AND SELECT A CONTRACTOR
After contacting potential builders, they will prepare an estimate that accounts for the anticipated costs of materials and labor, overhead, and a contingency to cover unforeseen expenses. It is then up to you to select a contractor based on your budget, time line, and assessment of qualifications.
PHASE 4: CONSTRUCTION
AND INSPECTION
Key Steps:
Obtain Bids and Select a
Contractor
Construct your ADU
Complete Inspections and
Obtain a Certificate of
Occupancy
43 Decisions... Decisions 03
Keep in mind that costs can fluctuate based on things like market volatility, variable prices of materials, and unforeseen circumstances and change orders. Additionally, the more detailed and thorough your plans are, the more accurate a contractor can be with their cost estimate. This is another reason it is a good idea to hire a professional to design your project.
Determine up front if the contractor is building on a fixed fee with contingencies for unforeseen conditions or if they are on a time and material basis with an upper limit. Be clear on your expectations and how change orders are to be handled and must be approved prior to incurring additional expenses. By agreeing on the process up front, you can avoid unexpected costs and control the budgets. If you do not manage this properly, costs could make it infeasible to meet your return on investment expectations and your financing capability. Insist on having the contractor show you why a change order is needed, why it was not in the original costs and how these costs are determined.
3.4.2 CONSTRUCT YOUR ADU
With a contractor in place, you’re ready to begin construction of your ADU. You and your contractor should be familiar with and take care to comply with La Mesa’s construction regulations to minimize impacts to you and your neighbors and avoid construction delays that may be caused by violating construction codes or regulations. Inspections of the work by City inspectors will be required at various stages throughout construction.
3.4.3 COMPLETE INSPECTIONS
At the end of the construction process, a final inspection will be conducted resulting in a final inspection approval if all conditions have been met. For a manufactured or pre-fabricated ADU, a certificate of occupancy will be issued.
Once this step has been completed, it means it is time to decide what you are going to do with your newly built ADU. Perhaps you have already made this decision, but the next section will walk through several considerations if you are planning to rent your ADU to a tenant.
The right professional, the right site plan and the right contractor can all make a big difference in the outcome of your project. Choose wisely and enjoy your accomplishments. Source: Dave Edwards, the Mercury News While some construction will be involved to prepare your site for a modular ADU, potential construction impacts can be reduced by having the ADU constructed off-site, and set in place on your property.
La Mesa Accessory Dwelling Unit Guide
44 3.5 PROPERTY MANAGEMENT
Whether your ADU is newly constructed or your property already includes an ADU, you will be responsible for managing the property should you decide to rent your ADU to a tenant. Renting an ADU can provide supplemental income and as a homeowner, you can use this income for mortgage payments, expenses, retirement, or other savings. Renting your ADU also provides more housing variety and options in your community and increases the value and equity in your property.
3.5.1 PREPARE DOCUMENTS
You may wish to rely on the expertise of a professional property management company to either assist with the initial set up of legal and lease documents or to provide ongoing management and maintenance for the ADU. Rental of an ADU to a tenant will require some initial setup including: the preparation of documents such as the drafting of a lease agreement, identification of liability issues, purchase of additional insurance, and tracking of expenses and other tax write-off accounting.
3.5.2 LIST YOUR PROPERTY AND FIND A TENANT
If you decide to play a hands-on role in the day-to-day operations of your rental property there are several responsibilities you must uphold. When considering your involvement, it is important to evaluate the potential time and costs involved in drafting documents, finding tenants, and completing maintenance. This includes finding the right tenants for your property and then deciding how you manage and maintain your rented space and may involve:
• Completing legal documents such as a lease agreement; • Researching and setting your rental rate;
• Photographing and advertising your property;
• Showing your property to prospective tenants;
• Screening renters and complying with equal housing protections; • Collecting a security deposit and rent;
• Responding in a timely manner to maintenance requests and repairs.
Seeing the list above may be daunting, and you may find that you don’t have enough time for the day-to-day tasks. In this case, a property management company could be hired to supervise and manage your property for a percentage of the gross rent collected or a flat fee. Finding tenants to rent your property includes making sure you know and understand fair housing laws.
LEARN ABOUT
FAIR HOUSING LAWS
Fair Housing in La Mesa
PHASE 5: PROPERTY
MANAGEMENT
Key Steps:
Prepare Documents
List your Property and
Find a Tenant
04 IDEAS TO CONSIDER
La Mesa Accessory Dwelling Unit Guide
46 4.1 DESIGN IDEAS
With the previous two chapters highlighting the ADU process and important considerations for each step, this final chapter aims to provide examples, ideas, and additional resources that may be helpful as you design your ADU. The chapter starts with a discussion of architectural styles and expressions and a photo gallery of ADU examples. Included next are sample site layouts that take into account different lot shapes, sizes, and conditions and sample building floor plans that range in size and number of stories. Finally, this chapter concludes with a set of relevant resources and links that are referenced throughout this guide.
Please note: La Mesa does not have design requirements for ADUs. The plans, images, and illustrations provided in this chapter are intended to serve as examples and ideas. They are not intended to substitute for the services of a design professional and should not be submitted as part of a building permit application.
4.2 ARCHITECTURAL EXPRESSIONS
It is usually desirable to have the new ADU structure or addition be compatible with the existing house and neighborhood. Some examples of compatibility are as follows:
• Architectural Style and Massing - This refers to the scale of the ADU as well as the design elements such as building orientation, roof pitch, wall cladding, and doors and window styles.
If the new structure is similar in style, roof slope and details, it would still be considered compatible with variations in color or materials. • Color and Materials - A new structure or addition with a different architectural style or massing could be tied together with consistent or compatible exterior colors and materials. • Garden Features - If the ADU is separate from the main house, the design could also be made compatible by incorporating existing garden features that bring the two residences together. • Unique Design - The design of detached ADU’s may be different from the main house if it still consistent with the general feel and architectural fabric of the neighborhood.
4.3 PHOTO GALLERY
Examples of design elements described above are provided in the images to the right with examples of compatibility noted with a checkmark and non-compatible elements noted with an X. The next page contains additional examples of ADUs of varying architectural styles including ADUs from garage conversions or additions and one-story detached ADUs.
Architectural Style and Massing
The primary residence and ADU have similar roof
slopes, trim elements, and materials, but differ in color.
The primary residence and ADU are of a similar scale
and orientation with similar roof pitch, color and details.
47 Ideas to Consider 04
Garden features such as French doors, lighting, and
pathways tie the style of the ADU to the main house.
This design provides an integrated deck design to bring the primary residence and ADU together.
ADU and primary house are not using compatible materials or styles making it seem forced and wedged in.
This ADU matches the primary residence in colors, wall
cladding as well as door and window details.
Similar colors and materials are used on the ADU.
This ADU uses different materials and styles and is out of scale with the primary and neighboring residences.
Though different architecture styles, the integration of the design is provided by wall cladding materials.
ADU is setback and scaled to fit with the neighborhood.
Color and Materials Garden Features Unique Design
La Mesa Accessory Dwelling Unit Guide
48 Source: buildinganadu.com
Source: buildinganadu.com
Source: buildinganadu.com
Samples of Architectural Styles Garage Conversion/Addition ADU Examples Samples of One-Story Detached ADUs
49 Ideas to Consider 04
4.4.1 STANDARD LOT - ATTACHED SINGLE STORY ADU
DESCRIPTION
This is a fairly typical property for La
Mesa, approximately 67’ wide by 120’
deep with a single-story home and
garage situated toward the center of the
site.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots under 10,000 SF are allowed
45% site coverage for an ADU
• .45 x 8,080 SF = 3,636 SF
• 3,636 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 3,636 SF - 2,337 SF = 1,299 SF
• The site coverage restriction would allow for an additional 1,299 SF to be built on this site. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
A desirable location for an ADU is behind the main residence when possible. For this property, suitable approaches may include a garage conversion, a detached backyard ADU, or the solution shown to the right.
An attached, single-story, ADU up to 1,200 SF would be a good option for this property that relates to the existing single-story main house that maintains a healthy buffer along the property edge.
4.4 SAMPLE PLANS FOR TYPICAL LA MESA LOTS
Standard Lot Example
Lot Size (SF): 8,228 SF
Max Lot Coverage (%): 45%
Max Lot Coverage (SF): 3,636 SF
Existing Building Footprint (SF): 2,337 SF
Remaining Lot Coverage (SF): 1,299 SF
Maximum ADU Size (SF): 1,200 SF
PROPERTY LINE PROPOSED ADU
SETBACK LINES
EXISTING
RESIDENCE
La Mesa Accessory Dwelling Unit Guide
50 4.4.2 STANDARD LOT WITH ALLEY ACCESS - TWO STORY ADU OVER GARAGE
DESCRIPTION
This standard shape lot consists of a singlefamily residential home facing the primary street with the back of the property facing an adjacent
alleyway. The home does not have a garage, and
parking is available on the primary street.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots under 10,000 SF are allowed 45% site coverage for an ADU • .45 x 7,603 SF = 3,421 SF
• 3,421 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage rules • Subtract the square footage of existing structures from the allowable site coverage square footage:
• 3,421 SF - 1,287 SF = 2,134 SF
• The site coverage restriction would allow for an additional 2,134 SF to be built on this site. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
Due to the access available from an alleyway, this lot provides an opportunity for a 2-level ADU or a second story ADU over a new garage oriented to the alleyway. This option provides separate access to the property for the two units, with the primary residence accessed from the street and the ADU access from the alleyway. When a property owner has access to a alley, it makes good sense to use it as the access to the ADU and assures that parking will not be on the local neighborhood streets.
Standard Lot with Alley Access Example
Lot Size (SF): 7,063 SF
Max Lot Coverage (%): 45%
Max Lot Coverage (SF): 3,421 SF
Existing Building Footprint (SF): 1,287 SF
Remaining Lot Coverage (SF): 2,134 SF
Maximum ADU Size (SF): 1,200 SF
PROPERTY LINE
SETBACK LINES
PROPOSED ADU
EXISTING
RESIDENCE
51 Ideas to Consider 04
4.4.3 STANDARD LOT WITH 40% SITE COVERAGE - TWO STORY
DETACHED ADU
DESCRIPTION
This is a standard shaped lot with alley access
and a building footprint that already covers
40% of the lot area. The addition of an ADU
allows the site coverage to increase to 45% for
lots under 10,000 SF.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots under 10,000 SF are allowed 45% coverage for a proposed ADU • .45 x 5,960 SF = 2,682 SF
• 2,682 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 2,682 SF - 2,384 SF = 298 SF
• The site coverage restriction would allow for an additional 298 SF to be built on this site. However, the City standards allow for properties that do not meet lot coverage standards to build up to an 800 SF ADU.
DETERMINE AN APPROPRIATE LAYOUT
Due to the lot coverage restrictions, a 2-level ADU would have a smaller building footprint than a single-story unit of the same size. With access available from an alleyway, this lot provides an opportunity for a 2-level ADU or a second story ADU over a new garage oriented to the alleyway up to a maximum of 800 SF.
Lot with Existing 40% Site Coverage Example
Lot Size (SF): 5,960 SF
Max Lot Coverage (%): 45%
Max Lot Coverage (SF): 2,682 SF
Existing Building Footprint (SF): 2,384 SF
Remaining Lot Coverage (SF): 298 SF
Maximum ADU Size (SF): 800 SF
SETBACK LINES
PROPERTY LINE
PROPOSED TWO
STORY ADU
EXISTING
RESIDENCE
La Mesa Accessory Dwelling Unit Guide
52 4.4.4 CORNER LOT - SINGLE STORY ATTACHED ADU
DESCRIPTION
This corner lot property consists of a 2-story
home and garage situated to the rear of the
site from the primary street frontage.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots under 10,000 SF are allowed 45%
site coverage for an ADU
• .45 x 6,721 SF = 3,024 SF
• 3,024 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 3,024 SF - 1,247 SF = 1,777 SF
• The site coverage restriction would allow for an additional 1,777 SF to be built on this site. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
The only available area on this site for an ADU up to 1,200 SF is on the open space to the east side of the lot. A detached unit would not provide adequate separation between structures. Therefore, an attached 2-story ADU would be the best option to maximize square footage while minimizing overall impact.
Corner Lot Example
Lot Size (SF): 6,721 SF
Max Lot Coverage (%): 45%
Max Lot Coverage (SF): 3,024 SF
Existing Building Footprint (SF): 1,247 SF
Remaining Lot Coverage (SF): 1,777 SF
Maximum ADU Size (SF): 1,200 SF
PROPERTY LINE
SETBACK LINES
PROPOSED ADU
EXISTING
RESIDENCE
53 Ideas to Consider 04
4.4.5 TRIANGULAR LOT - SINGLE STORY DETACHED ADU
DESCRIPTION
This large triangular shape corner lot
includes a single family residence with
multiple driveway access points.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots over 10,000 SF are allowed 40% site coverage
• .40 x 21,010 SF = 8,404 SF
• 8,404 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 8,404 SF - 4,111 SF = 4,293 SF
• The site coverage restriction would allow for an additional 4,293 SF to be built on this site. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
On a corner lot like the example to the right, the open space to the east side of the lot has adequate space for an ADU up to 1,200 SF. For this property, suitable approaches may also include a garage conversion or a detached backyard ADU. An attached, single-story, ADU up to 1,200 SF would be a good option for this property that relates to the existing singlestory main house and maintains a healthy buffer along the property edge. This approach maintains a private side yard and backyard while providing some yard for the ADU with separate parking coming off the main driveway.
Triangle Corner Lot Example
Lot Size (SF): 21,010 SF
Max Lot Coverage (%): 40%
Max Lot Coverage (SF): 8,404 SF
Existing Building Footprint (SF): 4,111 SF
Remaining Lot Coverage (SF): 4,293 SF
Maximum ADU Size (SF): 1,200 SF
SETBACK LINES
PROPERTY LINE
PROPOSED ADU
EXISTING
RESIDENCE
La Mesa Accessory Dwelling Unit Guide
54 4.4.6 SLOPED LOT EXAMPLE - SINGLE STORY DETACHED ADU
DESCRIPTION
This property consists of a single-family
residential home with an attached garage
located at the rear of a steeply sloping
lot. Sloped lots have additional grading
considerations. Consult with staff regarding
regulations that may apply to sloped lots.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots under 10,000 SF are allowed 45% site coverage for an ADU • .45 x 6,988 SF = 3,145 SF
• 3,145 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 3,145 SF - 2,123 SF = 1,012 SF
• The site coverage restriction would allow for an additional 1,012 SF to be built on this site. Therefore, this is the maximum size allowed for a new ADU.
DETERMINE AN APPROPRIATE LAYOUT
Given the slope and layout of the lot, the most feasible location for an ADU is toward the front of the property, either as a garage conversion or as a stand-alone detached unit. A detached ADU up to 1,012 SF could be placed along the front setback line with a front entrance oriented and connected to the primary street. Alternatively, a JADU could be incorporated on the lower level of the existing residence.
Sloped Lot Example (Down-slope)
Lot Size (SF): 6,988 SF
Max Lot Coverage (%): 45%
Max Lot Coverage (SF): 3,145 SF
Existing Building Footprint (SF): 2,123 SF
Remaining Lot Coverage (SF): 1,012 SF
Maximum ADU Size (SF): 1,012 SF
SETBACK LINES
PROPERTY LINE
EXISTING
RESIDENCE
PROPOSED ADU
55 Ideas to Consider 04
4.4.7 SLOPED LOT EXAMPLE - TWO STORY SPLIT LEVEL DETACHED ADU Sloped Lot Example (Up-slope)
Lot Size (SF): 6,693 SF
Max Lot Coverage (%): 45%
Max Lot Coverage (SF): 3,012 SF
Existing Building Footprint (SF): 2,000 SF
Remaining Lot Coverage (SF): 1,012 SF
Maximum ADU Size (SF): 1,012 SF
SETBACK LINES
PROPERTY LINE
PROPOSED SPLIT
LEVEL ADU
EXISTING
RESIDENCE
DESCRIPTION
This property consists of a single-family
residential home with an attached garage
located near the front of an uphill sloping
lot. Sloped lots have additional grading
considerations. Consult with staff regarding
regulations that may apply to sloped lots.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots under 10,000 SF are allowed 45% site coverage for an ADU • .45 x 6,693 SF = 3,012 SF
• 3,012 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 3,012 SF - 2,000 SF = 1,012 SF
• The site coverage restriction would allow for an additional 1,012 SF to be built on this site. Therefore, this is the maximum size allowed for a new ADU.
DETERMINE AN APPROPRIATE LAYOUT
Given the slope and layout of the lot, the most feasible location for an ADU is toward the rear of the property as a stand-alone detached unit.
A detached ADU up to 1,012 SF would be a good option for this property that relates to the existing single-story main house that maintains a healthy buffer along the property edge. The diagram shows a split level singe story with a two story in the back using a deck on the roof of the 1 story ADU.
La Mesa Accessory Dwelling Unit Guide
56 4.4.8 NARROW LOT - SINGLE STORY DETACHED ADU
DESCRIPTION
This long, narrow lot consists of a
single-story main residence and
attached garage nearly spanning the
full width of the lot.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots over 10,000 SF are allowed
40% site coverage
• .40 x 14,065 SF = 5,626 SF
• 5,626 SF is the allowable site
coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 5,626 SF - 1,580 SF = 4,046 SF
• The site coverage restriction would allow for an additional 4,046 SF to be built on this site. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
An extremely deep backyard seemingly provides ample room for a detached ADU with plenty of separation from the main house. However, given fire access requirements pertaining to hose-pull lengths, the ADU must be situated within 150’ of the primary road as there are no other available routes for a fire truck to access the rear portion of the lot.
Narrow Lot Example
Lot Size (SF): 14,065 SF
Max Lot Coverage (%): 40%
Max Lot Coverage (SF): 5,626 SF
Existing Building Footprint (SF): 1,580 SF
Remaining Lot Coverage (SF): 4,046 SF
Maximum ADU Size (SF): 1,200 SF
PROPERTY LINE
SETBACK LINES
PROPOSED ADU
EXISTING RESIDENCE
57 Ideas to Consider 04
4.4.9 LARGE LOT WITH ACCESSORY STRUCTURES - SINGLE STORY
DETACHED ADU
DESCRIPTION
This large site consists of a main
residence with an attached garage,
a detached car port, and backyard
storage shed.
CALCULATE ALLOWABLE SITE COVERAGE
• Lots over 10,000 SF are allowed 40% site coverage
• .40 x 18,084 SF = 7,234 SF
• 7,234 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Check to ensure that a 1,200 SF ADU adheres to the site coverage restriction
• Subtract the square footage of existing structures from the allowable site coverage square footage:
• 7,234 SF - 4,298 SF = 2,936 SF
• The site coverage restriction would allow for an additional 2,936 SF to be built on this site. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
The lot has ample room for an ADU up to 1,200 SF, and it may make sense to convert one of the existing accessory structures to an ADU. By transforming the car port structure into a single-story detached ADU, the main residence can preserve its backyard privacy while accommodating and ADU with its own separate surface parking area.
Lot with Accessory Structures Example
Lot Size (SF): 18,084 SF
Max Lot Coverage (%): 40%
Max Lot Coverage (SF): 7,234 SF
Existing Building Footprint (SF): 4,298 SF
Remaining Lot Coverage (SF): 2,936 SF
Maximum ADU Size (SF): 1,200 SF
PROPERTY LINE
SETBACK LINES
PROPOSED ADU
EXISTING
RESIDENCE
La Mesa Accessory Dwelling Unit Guide
58 4.4.10 LARGE LOT SPLIT - TWO RESIDENCES AND
TWO DETACHED ADUS
DESCRIPTION
There are some large lots like the example
shown here at 38,663 SF where there is
adequate space to subdivide the lot into two
parcels and incorporate a primary residence
and an ADU on each of the two lots.
CALCULATE ALLOWABLE SITE COVERAGE
• The R1S zone has a minimum area of 10,000 SF per lot therefore the lot can be split and still meet the minimum area for each lot • Lots over 10,000 SF are allowed 40% site coverage
• .40 x 38,663 SF = 15,465 SF
• 15,465 SF is the allowable site coverage for this property
CALCULATE MAXIMUM ADU SIZE
• ADUs are not to exceed 1,200 SF on any lot
• Ensure that a 1,200 SF ADU adheres to the coverage restriction • Subtract the square footage of existing structures from the allowable site coverage square footage:
• 15,465 SF - 3,751 SF = 11,714 SF
• The site coverage restriction would allow for an additional 11,714 SF to be built - enough for an ADU plus another primary residence with its own ADU. Therefore, a 1,200 SF ADU is permissible.
DETERMINE AN APPROPRIATE LAYOUT
Splitting this nearly 1-acre lot would allow the site to accommodate 2 primary residences, each with its own 1,200 SF ADU. With the establishment of a new address on the lot, a separate driveway into the new property would be provided off of the primary street.
Large Lot with Proposed Lot Split Example
Lot Size (SF): 38,663 SF
Max Lot Coverage (%): 40%
Max Lot Coverage (SF): 15,465 SF
Existing Building Footprint (SF): 3,751 SF
Remaining Lot Coverage (SF): 11,714 SF
Maximum ADU Size (SF): 1,200 SF
PROPERTY LINE
SETBACK LINES
PROPOSED NEW
SINGLE FAMILY
RESIDENCE
PROPOSED ADU
PROPOSED ADU
EXISTING
RESIDENCE
59 Ideas to Consider 04
Kitchen
Bedroom
Bth
Living
18' - 0"
38' - 0"
ADU Yard ADU
Main House
Yard
Entry
Main House
Street
Floor Plan
Site Plan
3D View
684 SF
Sample Floor Plan A
ADU Type: Detached ADU
# of Stories: One Story
Unit Size: 684 SF
Bedrooms: 1 Bedroom
Bathrooms: 1 Bathroom
4.5 SAMPLE ADU FLOOR PLANS
4.5.1 SAMPLE ONE STORY DETACHED ADU (1 BD / 1 BA)
La Mesa Accessory Dwelling Unit Guide
60 Living
Kitchen/Dining
Pwdr.
32' - 0"
18' - 0"
Closet
Bedroom Bedroom
Closet
Bath
Bath
32' - 0"
18' - 0"
Main House
ADU
ADU Yard Main House
Yard
Entry
Street
First Floor Plan
Second Floor Plan
Site Plan
3D View
1,152 SF
Sample Floor Plan B
ADU Type: Detached ADU
# of Stories: Two Stories
Unit Size: 1,152 SF
Bedrooms: 2 Bedrooms
Bathrooms: 2.5 Bathrooms
Living
Kitchen/Dining
Pwdr.
32' - 0"
18' - 0"
Closet
Bedroom Bedroom
Closet
Bath
Bath
32' - 0"
18' - 0"
Main House
ADU
ADU Yard Main House
Yard
Entry
Street
First Floor Plan
Second Floor Plan
Site Plan
3D View
1,152 SF
4.5.2 SAMPLE TWO STORY DETACHED ADU (2 BD / 2.5 BA)
61 Ideas to Consider 04
Bth
Kitchen
Bedroom
Bedroom
Bth
Dining
Living
22' - 0"
46' - 0"
Main House
ADU
ADU Yard
Main House
Yard
Entry
Floor Plan
Street
Site Plan
3D View
1,012 SF Sample Floor Plan C
ADU Type: Detached ADU
# of Stories: One Story
Unit Size: 1,012 SF
Bedrooms: 2 Bedrooms
Bathrooms: 1.75 Bathrooms 4.5.3 SAMPLE ONE STORY DETACHED ADU (2 BD / 1.75 BA)
La Mesa Accessory Dwelling Unit Guide
62 2 Car Garage
(Existing or new)
Main House
Driveway
Kitchen
Bedroom
Living
Bath
3' - 0"
min. at side P.L.
5' - 0"
Main House
ADU
ADU Yard
Main House
Yard
Entry
Above
Street
First Floor Plan
Second Floor Plan - ADU Addition Site Plan
3D View
ADU: 450 SF (or Garage Conversion)
2 Car Garage
(Existing or new)
Main House
Driveway
Kitchen
Bedroom
Living
Bath
3' - 0"
min. at side P.L.
5' - 0"
Main House
ADU
ADU Yard
Main House
Yard
Entry
Above
First Floor Plan
Second Floor Plan - ADU Addition Site Plan
3D View
ADU: 450 SF (or Garage Conversion)
2 Car Garage
(Existing or new)
Main House
Driveway
Kitchen
Bedroom
Living
Bath
3' - 0"
min. at side P.L.
5' - 0"
Main House
ADU
ADU Yard
Main House
Yard
Entry
Above
Street
First Floor Plan
Second Floor Plan - ADU Addition Site Plan
3D View
ADU: 450 SF (or Garage Conversion)
2 Car Garage
(Existing or new)
Main House
Driveway
Kitchen
Bedroom
Living
Bath
3' - 0"
min. at side P.L.
5' - 0"
Main House
ADU
ADU Yard
Main House
Yard
Entry
Above
First Floor Plan
Second Floor Plan - ADU Addition Site Plan
3D View
ADU: 450 SF (or Garage Conversion)
Sample Floor Plan D
ADU Type: ADU above garage
# of Stories: Two Stories
Unit Size: 450 SF
Bedrooms: 1 Bedrooms
Bathrooms: 1 Bathrooms 4.5.4 SAMPLE TWO STORY ABOVE GARAGE ADU (1 BD / 1 BA)
63 Ideas to Consider 04
Garage
JADU
Entry
Bedroom Bedroom
Bedroom
Living Room
Bath
Bath
Kitchen
Living
Dining
Kitchenette
Optional Connecting Door
Main House JADU
Entry
*
*
Garage
Bedroom Bedroom
Bedroom Bedroom
Bath
Bath
Kitchen
Living
Dining
Entry
Floor Plan - Existing House
1,500 SF
4 Bedroom/2 Bath
Floor Plan - with JADU
Main House: 1,050 SF
2 Bedroom/1 Bath
JADU: 450 SF
1 Bedroom/1 Bath
Main House JADU
Existing House
JADU
JADU Yard
Main House
Yard
Street
JADU
Entry
Garage
Site Plan
Sample Floor Plan E
ADU Type: JADU
# of Stories: One Story
Unit Size: 450 SF
Bedrooms: 1 Bedrooms
Bathrooms: 1 Bathrooms
ay
Main House
ADU
ADU Yard
Main House
Yard
Entry
Above
Street
Site Plan
3D View
Garage
JADU
Entry
Bedroom Bedroom
Bedroom
Living Room
Bath
Bath
Kitchen
Living
Dining
Kitchenette
Optional Connecting Door
Main House JADU
Entry
*
*
Existing House
JADU
JADU Yard
Main House
Yard
Street
JADU
Entry
Garage
Garage
Bedroom Bedroom
Bedroom Bedroom
Bath
Bath
Kitchen
Living
Dining
Entry
Floor Plan - Existing House Site Plan
1,500 SF
4 Bedroom/2 Bath
Floor Plan - with JADU
Main House: 1,050 SF
2 Bedroom/1 Bath
JADU: 450 SF
1 Bedroom/1 Bath
4.5.5 SAMPLE ONE STORY JADU (1 BD / 1 BA)
La Mesa Accessory Dwelling Unit Guide
64 4.6 ADDITIONAL RESOURCES
City of La Mesa Municipal Code
La Mesa ADU and JADU Regulations
https://library.municode.com/ca/la_mesa/codes/code_of_
ordinances?nodeId=TIT24ZO_CH24.05REZODEST_24.05.020PESTUS ADU: Section 24.05.020D8
JADU: Section 24.05.020D9
La Mesa Zoning Code
https://library.municode.com/ca/la_mesa/codes/code_of_ordinances?nodeId=TIT24ZO La Mesa Historic Preservation Ordinance
https://library.municode.com/ca/la_mesa/codes/code_of_
ordinances?nodeId=TIT25HIPR
City of La Mesa Forms and Handouts
ADU Quick Info Sheet
https://www.cityoflamesa.us/DocumentCenter/View/14739/ADU-Quick-Info-Sheet ADU FAQs Handout
https://www.cityoflamesa.us/DocumentCenter/View/14740/ADUs-FAQsHandout?bidId= JADU Quick Info Sheet
https://www.cityoflamesa.us/DocumentCenter/View/14741/JADU-Quick-Info-Sheet JADU FAQs Handout
https://www.cityoflamesa.us/DocumentCenter/View/14742/JADUs-FAQs-Handout Applications, Forms, and Informational Documents
https://www.cityoflamesa.us/112/Forms
Interactive Zoning Map
https://lamesaca.maps.arcgis.com/apps/webappviewer/index. html?id=8fe276fcec69432eab009b3f64eb35b9
Historic Landmarks in La Mesa Webpage
https://www.cityoflamesa.us/765/Historic-Landmarks
2021-2029 City of La Mesa Housing Element
https://www.cityoflamesa.us/DocumentCenter/View/17513/RevisedHousing-Element-041022?bidId= Residential Property Development Standards Handout
https://www.cityoflamesa.us/DocumentCenter/View/11269/Residential-DevelopmentStandards-08082018 Plan Review Submittal Checklist
https://www.cityoflamesa.us/DocumentCenter/View/346/Check-List-for-Plan-CheckSubmittals?bidId= Electronic Plan Review Portal
https://h9.maintstar.co/LaMesa/portal/#/
Fair Housing Webpage
https://www.cityoflamesa.us/127/Fair-Housing
General ADU Guidance Resources
AARP - The ABCs of ADUs
https://www.aarp.org/livable-communities/housing/info-2019/accessory-dwellingunits-adus.html BuildinganADU.com - ADU Photo Gallery
https://www.buildinganadu.com/adu-photos-home
California Department of Housing and Community Development - Accessory Dwelling Unit Handbook (July 2022)
https://www.hcd.ca.gov/sites/default/files/2022-07/ADUHandbookUpdate.pdf County of San Diego - Assessor’s Map Portal
https://www.sdarcc.gov/content/arcc/home/divisions/assessor/property-records.html County of San Diego - County Standard ADU Building Plans https://www.sandiegocounty.gov/content/sdc/pds/bldg/adu_plans.html Contractors State License Board
www.cslb.ca.gov
65 Ideas to Consider 04
Accessory Dwelling Units (ADUs) FAQs
COMMUNITY DEVELOPMENT DEPARTMENT / PLANNING DIVISION
8130 Allison Avenue, La Mesa, CA 91942
Phone: 619.667.1177 • Fax: 619.667.1380
INTRODUCTION
This Frequently Asked Questions (FAQ) was developed in response to common questions regarding development of Accessory Dwelling Units (ADUs). The regulations for ADUs can be found in La Mesa Municipal Code (LMMC) Section
24.05.020D8. For your reference and where applicable, the specific LMMC section related to each question is listed in parentheses at the end of the response. Please consult the Junior Accessory Dwelling Unit (JADU) FAQ for information about the development of JADUs.
1. What is an Accessory Dwelling Unit (ADU)?
An ADU is an attached or detached residential unit on the same lot as an existing or proposed dwelling in any single-family or multifamily zone, or on the same lot as existing multifamily dwellings in any residential or mixeduse zone. An ADU is an independent unit from the primary residence that provides its own kitchen, bathroom, living area, sleeping area, and entrance. ADUs are commonly known as granny flats, studio apartments, or motherin-law apartments. (LMMC 24.01.100)
2. Can I put an ADU on my property?
One ADU is allowed in conjunction with an existing or proposed dwelling on lots zoned for single-family or multifamily use (R1E, R1R, R1S, R1, R1A, R2, R3, and RB). (LMMC 24.05.020.D8a and 8e) At least one ADU, or a number of ADUs totaling not more than 25% of the existing dwelling units in a multifamily dwelling* structure, may be allowed on lots with existing multifamily dwelling structures in any residential or mixeduse zone. (LMMC 24.05.020.D8e.iii) Two detached ADUs are allowed in conjunction with existing multifamily dwellings* on lots zoned for residential or mixed-use. (LMMC 24.05.020D8e.iv.)
*Multifamily dwelling: Consisting of two or more attached dwelling units on the same lot
3. Am I allowed to have an ADU and a JADU on my property? An ADU and a junior accessory dwelling unit (JADU) may be developed on the same lot as an existing or proposed single-family residence. See JADU regulations for more information. (LMMC 24.05.020.D9)
4. What size ADU may I build?
The maximum floor area for an ADU is 1,200 square feet, including basements and attics. Any garages or accessory structures to the ADU are not included in the 1,200 sq. ft. calculation. (LMMC 24.05.020.D8a) ADUs created from the conversion of existing or proposed space within a single-family dwelling or existing accessory structure, or converted from non-livable space within an existing multifamily dwelling, are not subject to a size limitation. (LMMC 24.05.020.D8e)
5. May I build an ADU if my house is 1,200 square feet or less? Yes, an ADU may be built up to 1,200 square feet even when the existing house is 1,200 square feet or less. The ADU may be located in front or behind the primary home regardless of size, and the homeowner may choose
which to identify as primary residence and ADU. (LMMC 24.05.020.D8a) However, this does not apply to historical sites or within historical districts. (LMMC 24.05.020.D8c)
6. What are the setbacks for an ADU?
Generally, the setbacks for an ADU are the same as the underlying zone. However, an ADU may use reduced setbacks up to four feet from the rear and side property lines. An existing garage, accessory structure, or space entirely within an existing primary residence may be converted to an ADU, even if the structure doesn’t meet the setbacks of the underlying zone. All ADUs shall comply with all local building and fire code requirements, as appropriate. (LMMC 24.05.020.D8l)
7. What is the maximum height for an ADU?
An ADU on a lot with an existing or proposed single-family or multifamily residence is subject to the height limitations applicable to the primary dwelling. (LMMC 24.05.020D8)
8. What is the allowable lot coverage for an ADU project? Generally, properties in single-family residential zones are allowed up to 40% lot coverage. On lots that are 10,000 square feet in area or less and have an existing single-family residence, the lot coverage may be increased up to 45% for ADU projects. However, no lot coverage limitation, front setback, minimum open space, or minimum lot size requirement may prevent the development of an ADU that is at least 800 square feet with a minimum of four-foot side and rear setbacks, provided that all other development standards are met. (LMMC
24.05.020D8a)
9. Do I need to provide additional parking?
No additional parking is required for an ADU. If an ADU project involves the demolition or conversion of required parking spaces (e.g. garage or carport), those parking spaces are not required to be replaced. Any proposed parking spaces for ADUs are required to comply with LMMC Section 24.04 (Parking), and Parking Standards adopted by City Council.
(LMMC 24.05.020.D8f)
13. May I convert an existing garage or other existing accessory structure into an ADU? Yes. An existing garage, accessory structure, or space entirely within an existing primary residence, may be converted into an ADU even if the structure doesn’t meet the setbacks of the underlying zone. However, the Fire Marshal or the Building Official must determine the existing setbacks are sufficient for fire safety. (LMMC
24.05.020D8e)
14. What impact fees apply to the development of an ADU? Projects that only propose an ADU are exempt from public right-of-way dedication, improvement requirements, park fees, and maybe RTCIP fees. (LMMC 24.05.020D8a)
15. Am I required to install fire sprinklers for an ADU? An ADU is not required to have fire sprinklers installed, unless required for the primary residence. (LMMC
24.05.020D8a)
16. May I build an ADU if my property is an historic resource or in an historical district? An ADU may be built on a designated historical site and within a historical district; however, a detached ADU must be placed behind the primary residence and/or historic structure. Furthermore, the design and finished materials composition of the ADU must be architecturally compatible with the primary residence and/or historic structure, and must comply with historical preservation requirements in place at the time of construction. The
construction of an ADU is prohibited from removing any historically significant accessory structures. (LMMC
24.05.020D8c)
17. How do the Scenic Preservation Overlay, Hillside Overlay, Bowling Green Overlay, and Urban Design zones apply to ADU development?
Scenic Preservation Overlay Zone (P): The requirements of LMMC Section 24.09, Scenic Preservation Overlay Zone, apply to the development of ADUs, except that Planning Commission review is not required for a project that solely proposes an ADU. (LMMC 24.05.020D8d.i)
Hillside Overlay Zone (H): The requirements of LMMC Section 24.13, Hillside Overlay Zone, apply to the development of ADUs, except that Planning Commission review is not required for a project that solely proposes an ADU. (LMMC 24.05.020D8d.iii)
Bowling Green Overlay Zone: Any tree that was required to be planted per LMMC Section 24.17.030D that is disturbed by a project to build an ADU must be preserved in place, or replaced in kind on the same property if disturbed by the project. (LMMC 24.05.020D8d.iv)
Urban Design Overlay Zone (D): A project that solely proposes an ADU is not subject to the requirements of LMCC Section 24.11, Urban Design Overlay Zone, or the requirements of the Urban Design Program. (LMMC
24.05.020D8d.ii)
18. Are utility connections required for ADUs?
No new or separate utility connection between the ADU and utility (i.e., water and sewer) will be required for an ADU that meets the criteria of being contained wholly within the existing space of a single-family residence or accessory structure; has independent exterior access from the existing residence; and the side and rear setbacks are sufficient for fire safety. However, a new or separate connection directly to the utility shall be required for an ADU that cannot meet the aforementioned criteria and where the physical characteristics of the lot on which the ADU is proposed preclude connection to the existing utility connection of the primary dwelling. (LMMC 24.05.020D8g)
19. Do utility connection fees or capacity charges apply to ADUs? Utility connection fees and capacity charges apply to ADUs that voluntarily propose or are required to have a new or separate connection directly to the utility. The connection fees and capacity charges are to be proportionate to the burden of the proposed ADU, based upon either its size or the number of its plumbing fixtures impacting the water or sewer system. For attached or detached ADUs built on the same lot as an existing multifamily dwelling structure, a new or separate utility connection may be required, subject to a connection fee and/or capacity charge. (LMMC 24.05.020D8g)
20. May I rent my ADU?
Yes. An ADU may be rented. Some ADUs are required to be rented for terms longer than 30 days. (LMMC
24.05.020D8i)
21. Do I have to live on my property if I build an ADU? No. The property owner is not required to live on the premises. (LMMC 24.05.020D8i)
22. How do I apply for an ADU permit and how much does it cost for the permit? Submit a building permit application and building plans to the Building Division for review. A fee for the plan review is assessed based on several factors, including but not limited to: floor area size of the proposed ADU; whether or not the ADU will be attached or detached; and whether you will be converting an existing garage,
part of an existing primary residence, or existing accessory structure into an ADU. The Building Division can provide a rough estimate for the plan check fee once the needed information discussed above is provided. Building permit fees are determined during initial review of the building plans.
23. Does the City have pre-approved plans for ADUs?
Currently, the City of La Mesa does not have any pre-approved plans for ADUs. Other jurisdictions, including San Diego County, have pre-drawn plans available at no cost that may be used in La Mesa if adapted to meet the Building Division’s submittal requirements. The plans and a building permit application must be submitted to the Building Division for review.
24. How long will it take to obtain a building permit for an ADU? Is there an expedited review? Applications for a building permit submitted for ADUs must be approved or denied within 60 calendar days after receiving the application, if there is an existing single-family or multifamily dwelling on the lot. However, on lots with a proposed single-family dwelling, an ADU building permit application will be delayed until the City acts on the permit application for the single-family residence. (LMMC 24.05.020.D8h)
ACCESSORY DWELLING (ADU) UNIT QUICK INFO SHEET
COMMUNITY DEVELOPMENT DEPARTMENT / PLANNING DIVISION
8130 Allison Avenue, La Mesa, CA 91942
Phone: 619.667.1177 • Fax: 619.667.1380
Number of Units • On lots with an existing or proposed single-family or multifamily dwelling, one attached or detached ADU on lots zoned for single-family or multifamily (R1E, R1R, R1S, R1, R1A, R2, R3, and RB zones) (LMMC 24.05.200D8a or LMMC
24.05.020D8e)
• One JADU in addition to an ADU may be constructed on the same lot with an existing single-family residence (LMMC 24.05.020D8a.iv) • On lots with a multifamily dwelling (consistency of 2 or more dwelling units) (LMMC 24.05.020D8e):
o One or more ADUs converted from non-livable space, totaling not more than 25% of the existing dwelling units (LMMC 24.05.020D8e.iii) o Up to two detached ADUs per existing or proposed multifamily dwelling (LMMC 24.05.020D8e.iv)
Maximum Unit Size
(Living Area)
Attached or detached ADUs: 1,200 square feet in floor area, including basements and attics but does not include a garage or any accessory structure (LMMC
24.05.020D8a.ii)
Parking Requirements • No additional parking spaces required for an ADU (LMMC 24.05.020D8f.i) • Not required to replace parking space(s) removed when a garage, carport, or covered parking structure is demolished to construct an ADU or converted to an ADU (LMMC 24.05.020D8f.iii)
• When proposed, parking spaces for ADUs must comply with Chapter 24.04 (Parking) of the La Mesa Municipal Code, including but not limited to design requirements of the Parking Standards adopted by City Council (LMMC
24.05.020D8f.ii)
Front Setback Same as required for the primary dwelling (LMMC 24.05.020D8b.i) Side and Rear Setback • A four-foot minimum setback (LMMC 24.05.020D8b.ii) • Any ADU created by new construction, including additions to existing structures, that does not comply with setbacks established by the underlying zone must be maintained as an ADU (LMMC 24.05.020D8b.iii)
• No setback(s) required for conversion of existing space entirely within an existing primary single-family residence, detached garage or other accessory structure for a single-family residence that is converted to an ADU* (LMMC 24.05.020D8e.i) • ADUs may replace an existing garage or accessory structure located on the same lot as a single-family residence, in the same location* and to the same physical dimension** (LMMC 24.05.020D8e.i)
*The Fire Marshal or the Building Official must determine setbacks are sufficient for fire safety
**May be increased by 150 square feet solely to accommodate ingress and egress
Lot Coverage • Subject to the underlying zone
• On lots 10,000 square feet or less in area with an existing single-family residence, lot coverage may increase by 5% only for ADU projects (e.g., 40% lot coverage increases to 45% lot coverage in single-family residential zones) (LMMC
24.05.020D8a.iii)
• At least an 800 square foot ADU may be constructed using no less than four-foot side and rear setbacks, regardless of lot coverage limitation, front setback, minimum open space requirement, or minimum lot size requirement (LMMC
24.05.020D8a.vi)
Height An ADU on a lot with an existing or proposed single-family or multifamily residence is subject to the same height limitations applicable to the primary dwelling structure. (LMMC 24.05.020D8e.ii and iv)
Rental/Sale • May rent the primary dwelling and/or the accessory dwelling unit (LMMC
24.05.020D8i)
• Property owner is not required to live on the premises • ADUs developed in accordance with LMMC Section 24.05.020D8e must have rental agreements subject to a minimum period of 30 days • ADU may not be sold separately from primary residence, except as discussed in La Mesa Municipal Code Section 24.05.020D8(i)
Other • Not required to provide fire sprinklers unless required for primary residence (LMMC 24.05.020D8a.viii)
• Exempt from the requirements for public right-of-way dedication and improvement (LMMC 24.05.020D8a.ix)
• ADU building plans must be approved or denied within 60 calendar days after receiving the application, if there is an existing single-family or multifamily dwelling on the lot (LMMC 24.05.020D8h.iii)
• ADU not subject to Urban Design Overlay Zone or Urban Design Program requirements (LMMC 24.05.020D8d.ii)
• Additional regulations may apply on historic sites or districts(LMMC 24.05.020D8c) • Additional regulations may apply within overlay zones (LMMC 24.05.020D8d)
Junior Accessory Dwelling Units (JADUs) FAQs
COMMUNITY DEVELOPMENT DEPARTMENT / PLANNING DIVISION
8130 Allison Avenue, La Mesa, CA 91942
Phone: 619.667.1177 • Fax: 619.667.1380
INTRODUCTION
This Frequently Asked Questions (FAQ) was developed in response to common questions regarding development of Junior Accessory Dwelling Units (JADUs). The regulations for JADUs can be found in La Mesa Municipal Code Section
24.05.020D9. For your reference and where applicable, the specific LMMC section related to each question is listed in parentheses at the end of the response. Please consult the Accessory Dwelling Unit (ADU) FAQ for information about the development of ADUs.
1. What is a Junior Accessory Dwelling Unit (JADU)?
A JADU is a residential dwelling unit that is no more than 500 square feet in area, contained entirely within an existing or proposed single-family residence. (LMMC 24.05.020D9f)
2. May I put a JADU on my property?
One JADU is allowed in conjunction with an existing or proposed single-family residence, on lots zoned for singlefamily residential or multifamily uses (R1E, R1R, R1S, R1, R1A, R2, R3, and RB). JADUs are not allowed on lots with a multi-family dwelling (two or more attached dwelling units on a lot). (LMMC 24.05.020D9a)
3. May I put both a JADU and an ADU on my property?
Yes. A JADU and an accessory dwelling unit (ADU) may be developed on the same lot. (LMMC 24.05.020D9b)
4. What size JADU can I build?
The maximum floor area for a JADU is 500 square feet. (LMMC 24.05.020D9f)
5. Can an addition or modification to an existing single-family residence be used to create a JADU? Yes, it may be possible to make an addition or modification to an existing single-family residence to create a JADU. (LMMC 24.05.020D9f)
6. What type of entryway is required for the JADU?
A JADU requires a separate (private) exterior entryway. (LMMC 24.05.020D9f)
7. Do I need to provide a kitchen for a JADU?
A JADU shall include an efficiency kitchen, with the following components:
a) A cooking facility with appliances
b) A food preparation counter and storage cabinets that are reasonable to the size of the unit. (LMMC 24.05.020D9f)
8. Is a separate bathroom required for a JADU?
A JADU may share bathroom/sanitation facilities with the primary residence or may provide separate facilities. If sharing bathroom/sanitation facilities, an interior entry to the primary residence must be maintained to provide access to the sanitation facilities (LMMC 24.05.020D9f)
9. What are the setbacks for a JADU?
No setbacks apply to the conversion of existing space contained entirely within the primary residence to a JADU.
However, the JADU shall comply with all local building and fire code requirements, as appropriate. (LMMC
24.05.020D9g) A JADU that is created by new construction, including additions to a single-family residence, must comply with the setbacks established by the underlying zoning designation or overlay zone.
10. Do I need to provide additional parking?
No new or additional parking spaces are required for a JADU. (LMMC 24.05.020D9f)
11. May I convert an existing garage or other existing accessory structure into a JADU? The creation of a JADU must be contained entirely within an existing or proposed single-family residence. An existing attached garage or other existing attached accessory structure that shares a common wall with the primary dwelling may be converted into a JADU. (LMMC 24.05.020D9f)
12. What impact fees apply to the development of a JADU? Projects that only propose a JADU are exempt from public right-of-way dedication, improvement requirements, school fees, park fees, and maybe RTCIP fees. (LMMC 24.05.020D9m)
13. Are utility connections required for JADUs?
No, however, the City may inspect the JADU to verify it complies with development standards. (LMMC
24.05.020D9j)
14. Do utility connection fees or capacity charges apply to JADUs? No sewer or water connection fees required. (LMMC 24.05.020D9j)
15. Am I required to install fire sprinklers for a JADU? Fire sprinklers are not required for the JADU, unless required for the primary residence. (LMMC 24.05.020D9i)
16. Can I rent my JADU?
Yes. A JADU may be rented, but only with a rental agreement with terms greater than 30 days. It is important to note that a JADU cannot be sold separately from the primary residence. (LMMC 24.05.020D9d)
17. Do I have to live on my property if I build a JADU? Yes. A covenant will be recorded between the property owner and the City of La Mesa that requires the owner of record of the property to live in either the JADU or primary dwelling. (LMMC 24.05.020D9k)
18. How do I apply for a JADU permit and how much does it cost for the permit? Submit a building permit application and building plans to the Building Division for review. A fee for the plan review is assessed based on several factors, including but not limited to, the floor area size of the proposed JADU consisting of the floor area to be converted within a single-family dwelling and/or floor area of proposed (attached) addition to a single-family dwelling. The Building Division can provide you with a rough estimate for the plan check fee once you provide the needed information discussed above. Building permit fees are determined during review of your building plans. Before building permits can be issued, the property owner must record a covenant with the City of La Mesa agreeing to the size, occupancy and rental terms for a JADU identified in La Mesa Municipal Code Section 24.05.020D.
19. How long will it take to obtain a building permit for a JADU? Is there an expedited review? Applications for a building permit submitted for JADUs must be approved or denied within 60 calendar days after receiving the application, if there is an existing single-family dwelling on the lot. However, on lots with a proposed single-family dwelling, a JADU building permit application will be delayed until the City acts on the permit application for the single-family residence.
JUNIOR ACCESSORY DWELLING UNIT (JADU) QUICK INFO SHEET
COMMUNITY DEVELOPMENT DEPARTMENT / PLANNING DIVISION
8130 Allison Avenue, La Mesa, CA 91942
Phone: 619.667.1177 • Fax: 619.667.1380
Number of Units One JADU per existing or proposed single-family residence on lots zoned for single-family residential or multifamily uses (R1E, R1R, R1S, R1, R1A, R2, R3, and RB). One ADU may be constructed on the same lot.
Maximum Unit Size
(Living Area)
500 square feet in floor area, contained entirely within an existing or proposed single-family residence, or attached garage or other accessory structure Parking Requirements No additional parking spaces required Entryway Must have a separate (private) exterior entryway Kitchen Must have an efficiency kitchen, with the following components:
• A cooking facility with appliances
• A food preparation counter and storage cabinets that are reasonable to the size of the unit
Bathroom May share bathroom/sanitation facilities with the primary residence when an interior entry to the primary residence’s main living area is provided, or separate bathroom/sanitation facilities may be provided
Covenant Before building permits can be issued, property owner must record a covenant with the City of La Mesa agreeing to the size, occupancy and rental terms for a JADU identified in La Mesa Municipal Code Section 24.05.020D Fire Sprinklers Fire sprinklers not required for a JADU unless required for the primary residence.
Sewer & Water Separate sewer and water connections not required Owner Occupancy Property owner is required to live in either the primary dwelling or the JADU Rental Rental agreements subject to a minimum period of 30 days Other • JADU may not be sold separately
• Exempt from the requirements for public right-of-way dedication and improvement
• Impact fees not required