Licensed ADU Builder · Downey, California
ADU Construction
in Downey
Expand your property's potential with a professional ADU. From detached guest houses to garage conversions, we manage the entire process — permits, engineering, and construction. Family-owned since 1987. Class A, B & C-8 licensed.
Why Build an ADU?
Maximize Your Property Value
Adding an ADU in Downey is the most effective way to increase square footage and rental income. Our Class A, B, and C-8 licenses allow us to handle the full scope — including complex structural and civil work that most contractors cannot legally self-perform.
California's ADU laws have expanded dramatically since 2020. Reduced fees, streamlined permitting, and broader zoning approval mean your lot may qualify even if it previously didn't.
Serving Downey including Northeast Downey, Orange Estates, Downtown Downey and all surrounding areas.
ADU Types
ADU Services in Downey
Detached ADUs
Stand-alone backyard homes built from the ground up. Perfect for rental income or private guest housing.
High ROI InvestmentGarage Conversions
Transform your underused garage in Downey into a fully functional studio or 1-bedroom living space.
Most Cost EffectiveJunior ADUs (JADU)
Converting existing space within the main home footprint (like a spare bedroom) into an independent unit.
Fast PermittingAttached ADUs
Additions that share at least one wall with the main residence, often used for multi-generational living.
Seamless IntegrationDesign & Engineering
Full architectural services, structural engineering, and Title 24 energy calculations tailored to local codes.
Permits IncludedUtility Connections
Expert handling of sewer, water, and electrical upgrades required for a second legal dwelling.
Class A ScopeWhy Choose TDQ
The Only ADU Contractor with Class A Authority
Building an ADU in Downey requires more than a general contractor — it requires licensing authority to handle the civil and infrastructure components that most residential contractors cannot legally perform.
TDQ's Class A General Engineering license means we handle sewer laterals, utility connections, and site grading in-house — keeping your project on schedule under one accountable team.
Discuss Your Downey ADUClass A Licensed — Civil Work Included
Most contractors cannot legally complete the civil and infrastructure components of an ADU — sewer laterals, utility tie-ins, site grading. TDQ holds a Class A General Engineering license, giving us full authority to handle every phase in Downey.
One Contractor, Full Scope
From permits and foundation to framing, utilities, and final finishes — TDQ manages the entire project under one license. No coordination gaps, no finger-pointing between subs.
California ADU Law Experts
California ADU law has evolved significantly since 2020. We understand local permitting requirements, setback rules, and utility connection standards specific to Downey and surrounding municipalities.
Family-Owned Since 1987
Our business runs on referrals. Every ADU we build in Downey is treated like our own property — because our reputation depends on it.
Free Estimate
Start Your Downey ADU Project
TDQ Construction provides detailed written estimates before any work begins. Call or email us to discuss your property and ADU goals.
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