Huntington Beach HB Pre-Approved ADU Plan: 1 Bedroom, 490 sq ft
About this design
1-story, detached 490 square foot ADU. Listed by the City of Huntington Beach in its pre-approved ADU plan program. The City says: "Pursuant to California Assembly Bill AB-1332, the City of Huntington Beach is offering our HB Pre-Approved Accessory Dwelling Unit (ADU) Plan for use in Huntington Beach." Restriction as published: "*Please note: modifications or deviations from the HB Pre-Approved ADU Plan are not allowed." Code cycle shown: 2025 CALIFORNIA BUILDING CODE (plan title sheet). A site plan and site-specific documents are still required.
Site Plan
See how this design fits on your lot. Drag the ADU footprint to explore placement options.
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Features & Specifications
Design Details
Plan Details
Pre-Approved / Standard Plan Cities
Permit Fee Estimate
Jurisdiction
Some West LA and Studio City pockets are unincorporated LA County. Confirm your jurisdiction with the local building department if you are near a boundary.
Estimated Build Cost Range
Based on square footage and regional construction averages
This range is a speculative estimate based on typical LA-area construction costs ($350 to $600 per square foot) and the plan's square footage. It does not account for site conditions, permitting fees, utility connections, or material selections. Actual costs must be validated with a licensed general contractor or the plan's architect before making any financial decisions.
Rental Income Estimate
Build Location
Los Angeles, CA
Financing Your Build
Most homeowners finance ADU construction rather than paying cash. These are the common routes. Talk to a lender you choose; A-du does not arrange loans.
Illustration only, assuming a 20-year fixed loan at 8.5% APR on the estimated build-cost midpoint. Your rate, term, and eligibility depend on the lender and your finances. This is not an offer of credit; financing is provided by third-party lenders, subject to their approval.
Renovation & ADU construction loans
Lenders that underwrite on your home’s value after the ADU is built, often the best fit when current equity doesn’t cover the build.
Home equity (HELOC / home equity loan)
For owners with substantial equity, a line of credit against the home is typically the simplest and fastest route to fund construction.
Grants & public programs
California periodically funds ADU grant programs (e.g. the CalHFA ADU Grant for predevelopment costs, when funded). Worth checking before you borrow.
Source & Availability
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Important Information
Pre-Approval Status: Pre-approval information is provided by the vendor and should be verified directly with your local building department.
Cost Estimates: All pricing information is provided by the vendor as estimates only. Actual costs may vary.
Platform Role: A-du is a technology platform connecting landlords with design vendors. We do not provide architectural, engineering, or construction services.
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Optional; at checkout you pay only the flat fee (credit cards, when offered, add a 2.99% surcharge). This plan is free from City of Huntington Beach either way. Get the plan, then request permitting by Chris Koss, AIA from your plan dashboard.
Chris Koss, AIA, a California-licensed architect who owns A-du, provides this permitting service personally under a separate written agreement with you (the Permitting Services Agreement). It is not performed by A-du, and A-du takes no part of his fee. You can take the plan to your building department yourself instead.
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