Coming Soon: Backyard Cottages in Seattle

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A recently completed backyard cottage near Columbia City.

After a several year test period in southeast Seattle (south of I-90 and East of _I5), the City Council on Nov. 2nd unanimously approved an ordinance to allow backyard cottages to be built in all of Seattle.

Backyard cottages, formerly known by the not-so-friendly-sounding term DADU (detached accessory dwelling unit) have been championed by many homeowners, local politicians, architects, and urban planners as a way to increase density in our city and also give homeowners extra income to allow them to afford high mortgages and property taxes.  One homeowner is quoted by the City as describing a backyard cottage as a “mother-in-law unit with a little more breathing room”.

Of course, there are limits to where backyard cottages can go:  in the backyard, obviously, and your lot will need to be 4000 sf or larger.  And you can’t only have a backyard cottage if there already is an attached mother-in-law (ADU) unit in your house at present.

You can read the proposed ordinance here, as well as more information in a great packet put together by Seattle’s Department of Planning and Development (DPD).  Some highlights include the cottage being limited to 800 sf, not counting below grade area.  It must sit 5 feet back from the property lines, though if you have an alley behind your lot your cottage can abut that property line.  The height limit for your backyard cottage varies with your lot width, from between 15 up to 23 feet. You also need to provide a parking space for the cottage, as well as the one for the existing house.   There are some exceptions spelled out in the ordinance.

Building a new backyard cottage is a good chance for you to help green our city and world – many sustainable building strategies can be incorporated into your new backyard structure.  This includes solar hot water and PV (photovoltaic) panels, passive solar designrainwater harvesting, greywater reuse, or perhaps a green roof.  And don’t forget recycled and sustainably harvested materials.  Places such as the Re-Store, Second Use, and Earthwise all have a variety of all kinds of recycled building items from lumber to windows, doors cabinets and appliances.

The cost to build a backyard cottage in Seattle could run anywhere from $100/sf or more…there are many variables in materials, fixtures and finishes.

If you are interested in a free consultation to explore building a cottage in your backyard, drop us an email or call!  We can help you navigate the city’s zoning rules, work out a design, create plans and get it permitted and built.

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