Detached ADU
A separate small house in the yard. In Redmond, plan for fire sprinklers, the hydrant and access questions above, and new utility runs to the unit.
AIM Builders / ADU construction / Redmond
ADU Builder in Redmond, WA
AIM Builders is based in Redmond, so an ADU here is close to home for us. Adi walks your lot with you, we check what the city and your utility providers require for that address, and you get a written, itemized estimate before any work starts.
Planning sketchStart with a plan
Make room for what comes next.
- Detached, attached, or a garage conversion?
- What's the intended use: rental, family, or a home office/studio?
ADU rules in Redmond
What Redmond and state law allow.
Washington's 2023 ADU law, HB 1337, now RCW 36.70A.681, sets the baseline for Redmond. A February 2024 city planning memo lists what Redmond's code had to change to comply. The city must allow two ADUs on most residential lots, attached, detached or one of each (lots with critical areas or their buffers are the exception), and conversions of existing structures count. It may not require the owner to live on the property or prohibit selling an ADU separately.
State law also bars a city from capping ADU floor area below 1,000 square feet or setting a roof height limit under 24 feet, apart from a narrow exception. Redmond's zoning code sets the exact size, height and setback numbers for your zone, and we confirm those for your parcel before design starts.
Applications go through Redmond's Plan Review Online portal, and the city does not accept paper plans. Its residential application packet, published September 2026, says all new residential dwellings, ADUs included, require fire sprinklers. Demolition, mechanical, electrical, plumbing and fire permits are applied for separately from the building permit.
Rules checked against the sources listed below on October 26, 2026. Codes change, so we confirm the current requirements for your address before design.
Lot and site
Your Redmond lot decides the plan.
The same packet lists the site conditions that trigger a fire plan review: the nearest hydrant more than 300 feet from the building, an access grade over 10 percent, or an access road narrower than 14 feet or longer than 150 feet. Those questions come up often with a unit at the back of a deep lot. A geotechnical report may be needed for difficult soils or steep slopes, and homes on septic or a well need King County Health approval when the permit is submitted.
Trees count too. Redmond asks for a tree removal plan where one is needed, and a separate tree removal permit may apply. Walking the lot early shows us where a detached unit can sit, how a crew and materials reach it, and how far new lines run to sewer, water and power.
ADU types in Redmond
About our ADU construction Four ways to add a unit.
How it starts
From the first walk to a written estimate.
A consultation with Adi
Adi personally takes every in-home consultation. You talk through what you want to change, what matters daily and what you hope the home could do.
A walkthrough of your space
We measure, check structure and access, and look at the rooms as they are today, so the plan fits the house you actually have.
A written, itemized estimate and schedule
You see exactly what you are paying for, with the scope and schedule in writing before any demo starts.
Redmond ADU questions
Questions we hear in Redmond.
Can I build two ADUs on my Redmond lot?
State law requires Redmond to allow two ADUs on most residential lots, attached, detached or one of each, with lots that contain critical areas or their buffers as the exception. Whether two fit on your lot depends on its size, setbacks, access and utilities, which we check during the walkthrough.
Do I have to live on the property to rent out an ADU in Redmond?
No. Under RCW 36.70A.681, a city may not require the owner to live in the main house or the ADU.
Does a Redmond ADU need fire sprinklers?
Yes. Redmond's residential application packet says all new residential dwellings, including ADUs, require fire sprinklers. We carry that in the scope and the written estimate.
How do I apply for an ADU permit in Redmond?
Through the city's Plan Review Online portal. Redmond does not accept paper plans, and mechanical, electrical and plumbing permits are applied for separately. We coordinate the permit work as part of your project.
What does an ADU cost to build in Redmond?
We price each ADU from a written, itemized estimate after a site visit. Utility runs, site access, sprinklers and the type of unit move the number more than anything else, so we do not quote a figure before seeing the lot.
Step 1 of 2Your project
Request a free ADU consultation in Redmond
Let’s plan your adu or garage conversion.
We’ve selected the service you were exploring. Continue with it or choose another below.
Roof repair is available only as part of a larger remodeling scope.
Planning an ADU in Redmond?
Talk it through first.
Share your address and what the unit is for. Adi personally takes every in-home consultation, and the walkthrough covers the lot, access and utilities before any design or price.
Call (425) 671-2917Keep planning
ADU pages for nearby cities.
Each page covers that city's own ADU rules and permit process.
Free In-Home Consultation
Let’s look at your lot in Redmond.
Tell us what you would like to change. Adi visits, measures and listens, and you receive a written, itemized estimate with one point of contact from the first walkthrough to the final details.
WA Reg #AIMBUBL742DO · Bonded and insured ↗