Accessory Dwelling Unit Preapproved Standard Plan

Westminster Build Online Portal

Online submittal is now available. You may submit your application in person or online. To submit online, simply visit the portal to upload the required forms. Before applying, please review the submittal requirements to ensure a smooth process.

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Preapproved ADU Standard Plan Program

The City offers a pre-approved ADU standard plan program, allowing property owners to save time and costs by using these plans instead of preparing new architectural and construction drawings for their ADU.

Not Pre-Permitted
While the ADU plans are preapproved, they are not pre-permitted. A complete plan check, review process, and submittal of required technical documents are still required.

Site-Specific Requirements
Property owners must retain licensed professionals (e.g., designers or engineers) to prepare site-specific documents, including a site plan and existing floor plans of the main residence.

Using the City’s standard plans can help reduce time and costs associated with preparing construction drawings for the ADU structure. Please refer to the handout titled “Preapproved ADUs: What’s Preapproved & What’s Not” for a quick reference on which documents are covered by the standard plans and what additional materials are still required.

The following resources have been created to assist you in the preparation of your Preapproved ADU plan submittal. The Preapproved ADU plans available are to be used for the development of a detached ADU.

ADU STANDARD PLAN GUIDE

Provides program overview, process, and eligible projects.

WHAT'S PREAPPROVED, & WHAT'S NOT

Quick reference guide on which documents are preapproved and what is still required.

ADU STANDARD PLAN FEE SHEET

Provides a breakdown of applicable fees.

ADU STANDARD PLAN CHECKLIST

Provides a checklist of all required forms, documents, and plan details.

ADU STANDARD PLAN APPLICATION

To apply, use this form and fill out all sections as requested.

FULL ADU STANDARD PLAN PACKET

Consolidates all documents listed.

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ADU PREAPPROVED PLANS

The City offers detached ADUs in four (4) different sizes: 748 square feet, 791 square feet, 998 square feet, and 1,198 square feet. Out of these four sizes there are a total of six (6) different floor plans or plan types. Each plan type offers three (3) different roof designs consisting of a hipped truss roof or a gabled roof with either a conventional or truss design option. This provides a total of eighteen (18) different plan combinations to select from.

After selecting the plan, it must be printed out on standard 24’’ x 36’’ plans. Please see application checklist for more information.

DETACHED ADU STANDARD PLAN OPTIONS
PLAN 1	PLAN 2	PLAN 3	PLAN 4	PLAN 5	PLAN 6
748 sq. ft.	791 sq. ft.	998 sq. ft.	998 sq. ft.	1198 sq. ft.	1198 sq. ft.
2 Bedrooms 1 Bathroom	2 bedrooms 1 Bathroom	2 Bedrooms 2 Bathrooms	3 Bedrooms 2 Bathrooms	4 Bedrooms 2 Baths	3 Bedrooms 2 Baths
Conventional Gabled Roof Or Gabled Truss Or Hipped Truss	Conventional Gabled Roof Or Gabled Truss Or Hipped Truss	Conventional Gabled Roof Or Gabled Truss Or Hipped Truss	Conventional Gabled Roof Or Gabled Truss Or Hipped Truss	Conventional Gabled Roof Or Gabled Truss Or Hipped Truss	Conventional Gabled Roof Or Gabled Truss Or Hipped Truss

Note: Square footage shown is the net square footage measured from the interior walls.

PRE-APPROVED PLAN SETS Note: Plan square footage shown is the net square footage measured from the interior walls.
PLAN 1: 748 SQUARE-FOOT DETACHED ADU
PLAN 1: 748 SQ. FT., 2 BED, 1 BATH, CONVENTIONAL GABLED ROOF
PLAN 1: 748 SQ. FT., 2 BED, 1 BATH, GABLED TRUSS
PLAN 1: 748 SQ. FT., 2 BED, 1 BATH, HIPPED TRUSS

PLAN 2: 791 SQUARE-FOOT DETACHED ADU
PLAN 2: 791 SQ. FT., 2 BED, 1 BATH, CONVENTIONAL GABLED ROOF
PLAN 2: 791 SQ. FT., 2 BED, 1 BATH, GABLED TRUSS
PLAN 2: 791 SQ. FT., 2 BED, 1 BATH, HIPPED TRUSS

PLAN 3: 998 SQUARE-FOOT DETACHED ADU
PLAN 3: 998 SQ. FT., 2 BED, 2 BATH, CONVENTIONAL GABLED ROOF
PLAN 3: 998 SQ. FT., 2 BED, 2 BATH, GABLED TRUSS
PLAN 3: 998 SQ. FT., 2 BED, 2 BATH, HIPPED TRUSS

PLAN 4: 998 SQUARE FOOT-DETACHED ADU
PLAN 4: 998 SQ. FT., 3 BED, 2 BATH, CONVENTIONAL GABLED ROOF
PLAN 4: 998 SQ. FT., 3 BED, 2 BATH, GABLED TRUSS
PLAN 4: 998 SQ. FT., 3 BED, 2 BATH, HIPPED TRUSS

PLAN 5: 1198 SQUARE FOOT-DETACHED ADU
PLAN 5: 1198 SQ. FT., 4 BED, 2 BATH, CONVENTIONAL GABLED ROOF
PLAN 5: 1198 SQ. FT., 4 BED, 2 BATH, GABLED TRUSS
PLAN 5: 1198 SQ. FT., 4 BED, 2 BATH, HIPPED TRUSS

PLAN 6: 1198 SQUARE FOOT-DETACHED ADU
PLAN 6; 1198 SQ. FT., 3 BED, 2 BATH, CONVENTIONAL GABLED ROOF
PLAN 6: 1198 SQ. FT., 3 BED, 2 BATH, GABLED TRUSS
PLAN 6: 1198 SQ. FT., 3 BED, 2 BATH, HIPPED TRUSS

ADU CITY CONTACTS