Wei Chen

Wei Chen covers Bay Area permits, planning, ADU development, and code compliance for 9Builders. He translates the thicket of California and municipal building regulations — SB-9, AB-68, JADU rules, coastal commission requirements, and San Francisco unique permit process — into actionable steps for homeowners. Wei has followed California ADU reforms since 2017 and researches current planning department timelines, fee schedules, and approval requirements across Santa Clara, San Mateo, Alameda, and Contra Costa counties. His guides also cover how to work through code violation notices and bring older homes up to current standards without triggering unintended triggers for mandatory retrofit work.

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Posts by Wei Chen

Bay Area Green Building Requirements for New Construction and Additions

Bay Area Green Building Requirements for New Construction and Additions

Discover the Bay Area's green building requirements for new construction and additions, including energy codes, permits,...

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How to Design an ADU Floor Plan for Maximum Rental Income

How to Design an ADU Floor Plan for Maximum Rental Income

Maximize rental income with smart ADU floor plan design tips—learn how layout, size, and amenities can attract quality t...

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ADU Setback Requirements in the Bay Area Explained

ADU Setback Requirements in the Bay Area Explained

Learn the ADU setback requirements across Bay Area cities, including minimum distances from property lines, to plan your...

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Sunnyvale ADU Requirements: Permits, Setbacks and Fees

Sunnyvale ADU Requirements: Permits, Setbacks and Fees

Everything Sunnyvale homeowners need to know about ADU permits, setback rules, and fees to build a compliant accessory d...

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Fremont ADU Permit Guide: Requirements, Fees & Timeline

Fremont ADU Permit Guide: Requirements, Fees & Timeline

Navigate Fremont's ADU permit process with confidence—learn the requirements, fees, and timeline to get your accessory d...

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Oakland ADU Permit Requirements: A Homeowner's Guide

Oakland ADU Permit Requirements: A Homeowner's Guide

Learn Oakland's ADU permit requirements, from zoning rules to inspections, so you can confidently navigate the approval ...

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Junior ADU (JADU) Guide: Rules, Costs, and Permits in the Bay Area

Junior ADU (JADU) Guide: Rules, Costs, and Permits in the Bay Area

Convert your attached garage or basement into a legal Junior ADU in the Bay Area — covering local rules, permit steps, a...

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SB 9 Lot Split Guide: How to Split Your Property in the Bay Area

SB 9 Lot Split Guide: How to Split Your Property in the Bay Area

Split your Bay Area property in 2026 with SB 9: learn eligibility, costs, and steps to legally divide your lot and unloc...

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ADU Utility Upgrades: Electrical, Plumbing, and Permit Costs Explained

ADU Utility Upgrades: Electrical, Plumbing, and Permit Costs Explained

Plan your 2026 ADU utility upgrades with a clear breakdown of electrical, plumbing, and permit costs to budget confident...

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