Custom ADUs Built in the Bay Area | As Fast As 90 Days
Steel construction, premium finishes, factory precision, and a backyard unit you can actually count on.
4.9 Rating — 120+ Verified Google Reviews
Licensed CA Contractor
State-Approved Facility
Your ADU. Your Design. Built Smarter.
At Fast Struct, we don’t hand you a catalog and ask you to pick a box. We hand you a blank canvas.
Whether you’re envisioning a private backyard retreat, a rental income unit, or a spacious live-work studio — our team designs your ADU around your property, your lifestyle, and your budget. Every layout, room size, finish, and configuration is tailored from the ground up.
What does your perfect ADU look like? We’ll build it.
Feature Callouts
- Any layout, any size — From ultra-compact studios to spacious two-bedroom units
- Fully custom finishes — Flooring, cladding, rooflines, HVAC, electrical — all your choices
- Designed for your lot — We work around narrow driveways, tricky access, and tight lot lines
- Steel-framed precision — Every ADU built to millimeter tolerances in our Santa Clara facility
Get Your Free Estimate
Fill out the form and a Fast Struct specialist will reach out to discuss your project, walk you through your design options, and outline your build timeline. No commitment required.
"*" indicates required fields
Fast Struct: California's Premier ADU Builder
Adding an ADU to your California property shouldn’t mean months of noise, disruption, and uncertainty. Fast Struct built a smarter way.
As a licensed California contractor with a state-approved manufacturing facility in Santa Clara, we specialize in factory-built ADUs that arrive 95% complete and are craned into place in a single day. Your backyard stays clean, your neighbors stay happy, and you get a premium living space faster than any traditional builder can promise.
From permits to final delivery, your dedicated project manager handles every step. We’re not just ADU contractors near you. We’re your partner from day one.
Licensed CA Contractor
State-Approved Manufacturing Facility
Complete A-Z Project Management
Steel Construction — Built to Last
What We Build
From compact backyard studios to spacious two-bedroom units, every Fast Struct ADU is engineered to your site, your design, and your timeline.
Detached ADUs
Fully custom standalone steel-framed units built in our factory and delivered to your property
Junior ADUs (JADUs)
maller attached units that maximize your existing footprint
Modular ADUs
Arrive 95% complete, craned into place in a single day with minimal disruption
Panelized ADUs
Precision steel Smart Walls for properties with difficult access or tight lot lines
Multi-Unit ADU Developments
Scalable solutions for investors and developers adding multiple units
Permits, Site Prep & Delivery
We handle the full process from zoning to final handover
Two Paths. One Standard of Excellence.
We don’t force you into a box. Fast Struct recommends the construction method that fits your site, your design, and your timeline. No upsells, no guesswork.
The Modular Route — Ideal for Rapid Deployment
Your ADU is fully finished in our factory — including structure, electrical, and finishes — then craned onto your property ready to connect.
- Arrives 95% complete
- Craned into place in a single day
- Minimum disruption to your property and neighbors
The Panelized Route — Ideal for Design Freedom
Precision-engineered steel Smart Walls that pack flat and assemble rapidly on-site. Ideal for properties with limited access or wider, open layouts.
- Works on narrow driveways and difficult lots
- Supports wider, more open floor plans
- Maximum design customization
Your ADU, Built Smarter.
We’ve removed every painful step from the ADU process in California. Production moves off-site and into our facility so your backyard stays clean while your unit is being built.
Discovery
We assess your property, budget, and goals to recommend the right ADU type and construction method for your lot.
Design & Permit
Our team customizes your floor plan and navigates the local zoning and permitting process on your behalf. Because we're a state-approved modular factory, plans submitted through the state route are approved in days — not the months it takes traditional builders. You stay informed without the headache.
Fabrication
While your foundation is prepared on-site, your ADU is simultaneously precision-manufactured in our Santa Clara, California facility. This parallel process — steel-framed, factory-controlled, and built to tolerance — is exactly how we move so fast.
Assembly
Your unit arrives and is craned into place. Installation is rapid, clean, and quiet.
Handover
Walk into a fully finished ADU ready for occupancy. Keys in hand, no punchlist.
Why Bay Area Homeowners Choose Fast Struct for Their ADU
As Fast As 90 Days
Our parallel factory and on-site process means your ADU is ready faster than any traditional ADU contractor near you can promise.
Steel Construction — Not Wood
Every Fast Struct ADU is built with a steel frame, not wood. Steel is non-combustible, doesn't rot, and holds to millimeter-level tolerances. It's a fundamentally better building material — and one that 90% of our competitors simply can't offer.
State-Approved Facility = Faster Permits
As a state-certified modular factory, our plans go through the state approval route — meaning permits in days, not months. No other local ADU builder can say that.
Complete A-Z Solutions
ermits, design, fabrication, and delivery all handled by one team. One point of contact, zero coordination stress.
Arrives 95% Complete
Your ADU is craned onto your property nearly finished. Installation takes a single day, not months.
Factory Precision, Premium Finishes
Premium materials and finishes built to tolerances that traditional ADU builders simply cannot match.
Dedicated Project Manager
One person guides you personally from the first call to the day you hand over the keys to your tenant or family member.
Licensed CA Contractor + State-Approved Facility
Fully licensed, bonded, and compliant. Every build is warrantied and certified.
What Our Homeowners Are Saying
Locally Built. Serving the Bay Area and Beyond.
- Fast Struct
- 3395 Edward Ave Santa Clara, CA 95054
- (408) 702-9012
- Santa Clara County
- San Mateo County
- Alameda County
- Contra Costa County
- Santa Cruz County
Get Your Free ADU Estimate
Fill out the form and a Fast Struct specialist will reach out to discuss your property, walk you through your design options, and outline your build timeline. No commitment required.