ADU Builders Seattle – Seattle Modern Buildings ADU Builder
Fully Build a 1,000 sqft
Seattle DADU From $320k
We design, permit, and build Seattle DADUs as the area’s most trusted ADU builders – Financing options available.
10+ years building in Seattle
70+ homes built per year
From feasibility to move-in ready
4.8 Google Rating
Based on 30+ Reviews
600+ Homes Built
Across 10+ Years in Seattle
Seattle Permitting Expertise
ADU & DADU Specialists
3-Year Warranty
Because we stand behind our work
Why Build With Seattle Modern Buildings ADU Builder
Local experience.
Built on scale. Better value
We build DADUs the same way we build for ourselves – efficient, well-managed, and designed to perform. As experienced ADU builders in Seattle, our clients benefit from better pricing, faster timelines, and local permitting expertise.
Because we build 70+ homes per year in Seattle, our clients benefit from:
Better pricing through volume
Dedicated framing & sitework crews
Faster coordination across trades
See what type of ADU or DADU fits on your lot
We’ll review your property, check zoning and setbacks,
and show you what may be possible.
Seattle ADU & DADU Projects
Real Seattle ADU projects. Real Seattle neighborhoods. See what kind of accessory dwelling units we’ve built for homeowners across the city.
5906B 41st Ave.
304 32nd Ave.
8645 18th Ave SW.
Portfolio
Completed Project Locations
Real projects across Seattle neighborhoods. Click any pin on the map to explore.
600+ Homes BuiltClick a pin to see project photos and details
Why Seattle Homeowners Build DADUs & ADUs
More Space.
More Income. More Flexibility
Family Flexibility
Multi-generational living
Rental Income
$3,000-$4,000+/mo
Long-Term Asset
Build long-term property value
Development Potential
Build, hold, or resell
Use accessory dwelling units to increase property value and improve resale potential.
Get My Free Feasibility Review
Get a property-specific feasibility review from Seattle’s most experienced ADU contractors. Free, fast, and no obligation.
DADU & ADU Pricing In Seattle, WA
Seattle DADUs
Starting Around $320K
Typical 1,000 sqft Seattle ADU or DADU fully built and move-in ready:
Foundation & site work
Utility connections
Cabinets & finish materials
Final inspections
Starting around
$320K
See what fits on your lot
We’ll review your zoning, sizing & placement options — free.
A Clear Path From Idea to Move-In Ready
We handle the process from feasibility and permitting to final ADU construction.
Feasibility Review
We assess what fits on your property and define the right project path.
Design & Permitting
Budget & Financing
We define realistic costs and financing options before construction begins.
ADU Construction
Your Seattle ADU is built by one managed team with a dedicated point of contact.
Move-In Ready
What Seattle Homeowners Say About Building With Us
Real reviews from real Seattle homeowners who trusted us with their DADU & ADU construction projects.
“I’ve been working with Modern Buildings Seattle for the past two months on design plans, and it’s been an excellent experience. Their team is knowledgeable, responsive, and really takes the time to understand your vision. The process has felt smooth and collaborative from start to finish. Highly recommend them if you’re looking for thoughtful, high-quality design work!”
“Met with Ivan and Peter, they were extremely knowledgeable and helped answer all my questions about DADU construction code in Seattle. They did preliminary feasibility for my parcel to determine what can be built and estimated the time and cost. Very professional. I can recommend reaching out to Modern Buildings if you are thinking about building on your property.”
“Modern Buildings have been fantastic to work with. They helped me evaluate feasibility on multiple development projects and went deep into layout options, constraints, and risks. Communication has been excellent — quick responses, clear explanations, and very thoughtful insights throughout the process. I feel much more confident moving forward and am excited to use them for my next construction build.”
“I worked with Vlad and Peter on a feasibility study for our property, and the experience was excellent. They demonstrated great patience, provided clear and thoughtful guidance, and addressed all of my questions in detail. Their knowledge and responsiveness throughout the process gave me confidence and made the experience smooth and efficient. I highly recommend Seattle Modern Buildings and their team.”
“I am in the early stages of building a 1000 sq ft backyard cottage and am happy with the well researched feasibility study and options they presented. I have spoken with many design build firms, architects, and developers in the Seattle area. As a small homeowner, their process makes the most sense for me. I am excited to start the permitting next!”
“We hired Modern Buildings to bring our rental property vision to life, and they absolutely delivered. Quality craftsmanship and quick turnaround. Couldn’t be happier.”
PROPERTY FEASIBILITY REVIEW
See What You Can Build
on Your Lot in Seattle
What accessory dwelling units can realistically fit on your property
Rental and resale potential for your accessory dwelling units
Call us at (206) 840-8356
FAQ
Seattle DADU & ADU Questions
Common questions from Seattle homeowners who are considering building a DADU or a custom ADU.
How much does an ADU cost with Seattle Modern Buildings?
Most 1,000 sq ft DADUs start around $320K for a full build, including foundation, utility connections, kitchen, cabinets, and standard appliances. Final cost depends mostly on site conditions, utility access, design complexity, and finish level.
How long does it take to build with your team?
Most ADU projects take several months from planning to completion. In most cases, design, architectural plans, and structural engineering take about 2 months. Permitting depends on jurisdiction and current city review times — at the moment, approval for one DADU in King County is often around 2 months, while Seattle typically takes closer to 4–5 months. Construction usually takes about 3–6 months depending on site conditions, scope, and project complexity.
Can I rent out my ADU in Seattle?
Yes. Seattle homeowners can typically use an ADU as a long-term rental, guest house, or flexible living space for family. The best rental strategy depends on your property, layout, and long-term goals.
Do you handle permits and city approvals?
Yes. We handle feasibility, zoning review, design coordination, permitting, and city approvals as part of the process, so you do not have to manage multiple teams on your own.
How do I know what can fit on my property?
The fastest way to find out is to send us your address. We review zoning, lot layout, setbacks, and site constraints to help you understand what can fit, what it may cost, and whether an ADU makes sense for your property.