I researched zoning variances before I put my home on the market, but got informal feedback from the city that UW ‘protects’ the zoning ratios around the school to prove (on paper, at least) that there’s housing available for graduate/older students and staff, despite the prevalence of under-the-table rentals). The implication was it would not be granted until UW changed their ratio or impact area. I have not heard about ADUs in the area, nor seen many marketed in houses known to be rentals.

“with all the new apartments coming on line”
There are not a lot of new apartments coming on line. Seattle lost over 5000 rental units to condo conversions and development since 2003. The apartments coming on line are a drop in the bucket. The condo conversions reverting back to apartments not many. Those under construction or in the permit process won’t have any serious impact until 2010 at the earliest.

An ADU is the official term for the MIL. ADU has rules. And ADU is an owner occupied single family residence with an extra livable unit. It is not considered multi family. It is not zoned as multifamily. It must be owner occupied. Lending on property is based on the zoning and use. If a single family home has a non conforming second unit, then the lender will consider it as a single family home.

Generally, you must claim the rental income as income. You won’t have any capital gain on the rental portion of an attached ADU. The attached ADU such at the basement or attic falls under the owner occupied capital gains exemption up to $250K for a single person and $500k for a married.

Generally, and ADU adds some additional value.

The decision to rent or lower the price of the home to get it sold can be a complicated discounted cash flow analysis problem involving cash flows and the Time Value of Money. Ask for help from your CPA or another number crunching professional. What the market rent, cost of renting, cost of owning, lease term, time to sell if the price is dropped, time to sell if the price isn’t dropped, alternative uses of differences in cash flows, investment rate, tax rate, etc?

You bring up a good point: how does adding an additional unit (either permitted or not) effect the value of a home? The way it’s advertised? What it can legally be used for?

I added an attic apartment to my house a few years back when I had to replace the roof. I went through the whole permit process and now have a legal Accessory Dwelling Unit (ADU) recognized by King County. Even so, the city still classifies my house as a single-family (though I believe my neighborhood, Squire Park, is zoned multifamily?)

I’m thinking a MIL (mother-in-law) unit isn’t legal, while an ADU is? Jargon vs. legal definitions: very confusing in the real estate world. Maybe your agent can clarify for you and us?

Regardless, even if you can’t officially advertise it as a multi-family, maybe the remarks could include something like, “3-bedroom suite in lower level currently generates rental income.” That way, you’re technically not claiming multi-family, but you’re letting buyers know that the space exists. How they choose to use that space is up to them.

Just like in the U-district, there are several shared houses in my hood–some are legal multifamily and some not.

I’d certainly be interested in some input from agents. What are the legal/ethical standards in advertising snigle-family homes that are really used as multi family? If TF had permitted the ADU could it be advertised as multi-family?

In particular, I’m curious as to whether having the ADU makes my house worth more or less than if it were a single-family house with the same square footage.

Any of you pros want to jump in?

For those interested in this thread and part-rental homes, what would you look for when looking for such properties? Under my agent’s guidelines, I nearly have to let people discover the rental opportunity in my house.

There are a couple of good sites that do rentals though-mynewplace.com and rent.com.