ADUs come up more often in Idaho and Washington deals now that both states have eased the rules. Buyers ask whether a backyard can hold a second home, and sellers want to know how to market one they already have. This real estate agent ADU guide covers what you need to answer those questions well.
You don’t need to be a builder. You need to know what makes a lot ADU-ready, which questions to send to the city, and where to point clients for costs and timelines.
Why ADUs matter to your buyers and sellers
Buyers look at ADUs for a few reasons: room for an aging parent, a first place for a grown kid, a home office, or rental income. A lot that can hold an ADU gives them all of those options.
The rules changed in both states. Our guides to Idaho’s ADU law, SB 1354, and the Washington ADU law cover what homeowners can build. The Washington Department of Commerce also keeps a plain summary of the state’s ADU requirements.
Real estate agent ADU checklist: spotting an ADU-ready lot
When a buyer asks whether a property could hold an ADU, these are the things to look at first:
- Zoning. Does the zone allow a detached ADU? Confirm with the city planning department, not just a listing note.
- Space and access. Is there room behind or beside the house, and can a crew and materials get there?
- Utilities. How far are water, sewer, and power from where the ADU would sit?
- Setbacks and slope. How close can it go to the lot lines, and is the ground fairly flat?
- HOA and CC&Rs. Private rules can limit a second unit even where the city allows one.
Questions buyers will ask, and where to send them
- “What does an ADU cost?” Kit Culture’s ADU plans start at $57,120 for the 490-square-foot Sunrise. The 495-square-foot Paisley is $65,940, and the 445-square-foot Getaway is $68,220. All three are one bedroom, one bath. Other plans are call for pricing, and the full list is in our ADU plan library. If a client needs two bedrooms, the 799-square-foot Cottage kit is $99,500. Site work, foundation, utilities, permits, labor, delivery, and sales tax come on top. Our breakdown of the total cost of a kit home lays it out.
- “How would I pay for it?” Our guide to kit home financing covers the common routes.
- “Could I rent it out?” Often, but the rules vary by city. Our ADU rental income guide covers the math and the questions to ask the city.
Helping sellers with an existing ADU
A permitted ADU can be a strong selling point if the paperwork backs it up. Ask your seller for permits and the final inspection, any leases and rent history, and the unit’s utility costs. Market it as flexible space, not just a rental. Our guide on whether an ADU adds value to a home covers how appraisers and buyers look at one.
Working with Kit Culture
You handle the lot and the deal. We handle the home side: which kit fits the lot, what the package includes, and what comes on top. If you’ve got a client looking at a lot in Idaho or eastern Washington, send us the details and we’ll talk through what fits before they commit.
We’re also rolling out a formal commission program for real estate agents who bring clients to Kit Culture. If you’d like the details, give us a call and ask about the agent program.
Real estate agent ADU FAQ
Can I list a property as “ADU-ready”?
Only describe what you’ve confirmed. Zoning that allows an ADU is a fact you can check with the city. Whether a specific ADU fits on the lot depends on setbacks, utilities, and site conditions, so frame it as potential, not a promise.
Do I need to know building codes?
No. Know enough to spot the big issues, then send code questions to the city planning department and building questions to the builder.
Can a buyer build an ADU right after closing?
Usually not right away. Plans, permits, and site work come first. Help them get a realistic timeline from the city and the builder before they plan around move-in dates.
The bottom line
ADUs are becoming part of more conversations in Idaho and Washington. Learn to spot an ADU-ready lot, confirm the rules with the city, and know where to send buyers for costs and financing. That makes you the agent who can answer the question instead of guessing.
If you’d like to talk through a client’s lot or hear about our agent commission program, give us a call.
