Accessory Dwelling Unit - Step by Step Guide - planning - building & safety - fire prevention

Oct 23, 2026

Accessory Dwelling Unit step-by-step guidance covering prerequisite checks, planning confirmation, and development requirements. It instructs applicants to verify zoning allows ADUs, review development standards, and coordinate with a designer to prepare required plan sets including architectural elevations, floor, electrical, plumbing, mechanical, foundations, structural frame, truss calculations, energy, solar, and California Green Building Standards sheets. Fire prevention steps address Title 7A/Title 14 compliance in high-risk zones, sprinkler triggers based on will-serve water flow, hydrant distance thresholds, and access-road/street proximity. It also outlines site electrical planning and possible second-meter requirements, including encroachment permits and contact points for utilities.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages18

Reading Time45 min

AccessFree to download

planning

building & SAFETY

fire PREVENTION

stepFOUR

stepFIVE

stepSIX

stepSEVEN

stepEIGHT

building & SAFETY

stepNINE

ADU forYOU Accessory Dwelling Unit-Step by Step Guide ENTER planning stepONE stepTWO stepTHREE I have confirmed the zoning designation for my property is residential and allows for an Accessory Dwelling Unit by visiting HERE, emailing [planningemail@moval.org](planningemail@moval.org), or calling 951-413-3206 . My property is developed with either a single or multiple family residence or I am prepared to submit plans for approval of a new single or multiple family residence atthe same time as I submit for my Accessory Dwelling Unit. I have reviewed the development standards for my property and am working with a designer to prepare the required plans to ensure that all development standards are met. CONTINUE planning Please note that there are fees associated with new development. Some of which are based on the size of your property and the size of the building you wish to construct. You are encouraged to reach out to the Planning Division by emailing [planningemail@moval.org](planningemail@moval.org) or calling 951-413-3206 for more information. CONTINUE building & SAFETY Please have your Plan Designer prepare the following plans. · Architectural Elevations sheets Four sides · Floor Plan · Electrical Plan · Plumbing Plan · Mechanical Plan · Foundations Plan · Structural Frame Plans 1st floor frame plan, 2nd floor frame plan, roof plans, construction notes, detail sheets · Truss Calculations and layout plan (if applicable, as determined by the plans designer) · Energy Calculations · Solar Plans · California Green Building Standards Mandatory required sheets. There are a few additional plans that you may need to prepare which we will walk you through in the next steps. CONTINUE fire PREVENTION stepFOUR stepFIVE If your property is located within a High or Very High Fire Severity Zone as identified on the State Fire Hazard Severity Zone Viewer located at [https://egis.fire.ca.gov/FHSZ/](https://egis.fire.ca.gov/FHSZ/ your)[ your](https://egis.fire.ca.gov/FHSZ/ your)[ ](https://egis.fire.ca.gov/FHSZ/ your)designer will need to prepare plans that comply with Title 7A (Construction) Title 14 (Fire setbacks), and prepare a Fuel Modification Plan. Your ADU will need fire sprinklers if they are installed in the primary dwelling. Please work with you designer to prepare plans. CONTINUE fire PREVENTION stepSIX You will need to have a will serve letter that is less than 12 months old from your water service provider which identifies the amount of water that is available to your property. If you have a water flow over 1000 gallons per minute at 20 pounds per square inch, you can move to the next step. If your will serve letter identifies that your water flow is below 1,000 gallons per minute and above 500 gallons per minute at 20 pounds per square inch for one hour, you will need to have a fire sprinkler plan designed for your ADU. If your will serve letter identifies that you are below 500 gallons per minute at 20 pounds per square inch for one hour, you will need to contact your water service provider to develop a plan for service. Your service provider is identified on your water bill. You can reach Eastern Municipal Water District [www.emwd.org](www.emwd.org), email [Customerservices@emwd.org](Customerservices@emwd.org), or call 800-426-3693 . You can reach Box Springs Mutual Water Company at INFO@BSMWC.ORG or 951-653-6419 . CONTINUE fire PREVENTION stepSEVEN If a fire hydrant is within 400 feet of your property, you can move to the next step. If a fire hydrant is between 400 feet and 600 feet of your property, you will need to have afire sprinkler plan designed for your ADU. If a fire hydrant is greater than 600 feet from your property, please contact your water service provider to develop a plan for service. You can reach Eastern Municipal Water District [www.emwd.org](www.emwd.org), email [Customerservices@emwd.org](Custome

FAQs

How do I confirm my property is eligible for an Accessory Dwelling Unit?

Confirm zoning designation is residential and allows an Accessory Dwelling Unit by visiting the provided link, emailing the Planning Division, or calling the listed planning phone number.

What plans must my plan designer prepare for building & safety requirements?

The guide lists architectural elevations (four sides), floor plan, electrical, plumbing, mechanical, foundations, structural frame plans (including multiple floors and roof plans), truss calculations/layout (if applicable), energy calculations, solar plans, and California Green Building Standards mandatory sheets.

When are fire sprinkler plans or fire-related compliance needed?

Compliance may be required in High/Very High Fire Severity Zones with Title 7A/Title 14 and a Fuel Modification Plan. Sprinkler needs depend on will-serve letter water flow thresholds, and hydrant distance thresholds determine whether additional sprinkler planning is required.

Oct 23, 2026

Uploaded by Sophia Brooks