urban | design.banter :: More Guidelines for ADU's-North Puget Sound

Each Friday we bring you  urban | design.banter 
:: infill | re-knitting our urban fabric | cohousing | keeping small towns from becoming suburbs :: why shouldn't where you live be somewhere you would want to visit?

In this series, we are giving you a brief overview of what some jurisdictions allow. Not all of them allow Accessory Dwelling Units (ADU's) in single family zones. If you would like to build one, or just advocate for the cause of affordable housing, mixed income neighborhoods, density, accountable tenant-landlord relationships (landlord lives in the house, so he is not absentee, renter lives right there, so is held accountable), and allowing families to provide shelter for other family members on their land, talk to your local government. Many jurisdictions are realizing that allowing ADU's can help us reach many of the goals mentioned above and are changing their zoning codes to allow them. Here are some results of a questionnaire for the City of Seattle from our first article on ADU's:

Among those aware of a backyard cottage in their neighborhood:
• 71% said that the backyard cottage in their neighborhood fit in with the surrounding homes.
• 84% noticed no impacts on parking or traffic directly related to the backyard cottage.
• 83% were supportive or strongly supportive of backyard cottage policy.

Anacortes 

• Medium Density Residential zones: "caretaker's cottage" up to 140 SF. May need to fight for ADU. Attached ADU would be no problem in this zone as duplexes are allowed.

• Single Family Residential zones:  No ADU's allowed currently

Bellingham

The city allows attached ADUs only (for instance, in a basement, as a flat on the second floor, or in addition), unless you want to renovate and existing detached unit. Here are some of their guidelines:

• The floor area of ADU must not exceed 40% of the area of the primary residence, with a maximum area of 800 square feet (for both attached and detached), two bedrooms, three people
• Only one entrance can be visible from the street, and any off street parking displaced by the new building must be replaced. Parking for the ADU should preferably be off the alley, if possible.
• One of the building must be owner occupied. 
• More information here
• Here is some information on the code requirements in regard to construction, including creating a one hour fire separation between the units

Island County (Oak Harbor, Camano, Whidbey Island)

• ADU's (in this code referred to as detached accessory Dwelling Unit or Guest Cottage) are allowed in most zones (Rural Residential zones must have a lot size of at least 1 acre). 
• Must not exceed 1,000 square feet or 20% of floor area of the primary residence, whichever is larger (Max 2,500 square feet)
• ADU and primary residence must share a driveway
• Thirty five ADU's may be permitted each year in the county

Let us know if you are curious about ADU's and your city or county has not been covered.

Other blog entries about ADU's: ADU 101 with rules for Seattle/King County and San Juan Islands

 
 

urban | design.banter :: More Guidelines for ADU's

Each Friday we bring you  urban | design.banter 
:: infill | re-knitting our urban fabric | cohousing | keeping small towns from becoming suburbs :: why shouldn't where you live be somewhere you would want to visit?

This summer we posted a summary on Accessory Dwelling Units (ADU's): a brief explanation, some benefits, and regulations for Seattle and King County. Below we will outline the regulations for the San Juan Islands.

Accessory Dwelling Units (ADU's) have become more popular and acceptable in the past few years. The City of Seattle began allowing for ADU's in all residential zones (it had previously been only some south Seattle neighborhoods) in 2009. San Juan County allows for a limited number of permits for ADU's each year.

An ADU can be attached, as in a basement apartment, or detached, as in a backyard cottage, carriage house, or alley flat. The implementation of ADU's can fulfill many goals of sustainable development, including density, affordable housing, and smaller house sizes. As our urban fabric is "re-knit", neighborhoods can become more dense, creating more demand for services, therefore creating more opportunities for walkable neighborhoods and less dependence on a car.

Truly sustainable development also includes social goals, many of which are also met by integrating ADU's: a way for homeowners to have a separate income stream, a mix of income and ages; the ability to stay in one neighborhood through varying phases of life, therefore creating lasting community: kids can live in a backyard cottage as they start on their career path, elderly parents or relatives can live in smaller spaces that require less upkeep and be close to their children and grandchildren. The term "mixed income" may be worrisome, but from a social standpoint, renting out an ADU can more successful than an absentee landlord renting a house, in that owners are close to the rental unit, tenants are close to their landlord, so each keeps an eye on each other. The Kentlands Development in Maryland (designed by New Urbanism pioneers DPZ)  is a neighborhood that has successfully integrated market rate, large suburban housing with backyard rental units. An often cited example is of a woman who lived in her ADU and rented out her large house in order to save money and pay off her mortgage.

Anna spoke to BUILDERnews magazine about the benefits of building an ADU or guest apartment. See the article, including photos of two of our projects that include these structures here.

Hare House in Friday Harbor, Second Floor Plan: an apartment over an office and garage can be used for family, or rented out for extra income.

San Juan County:

San Juan County defines an ADU as "a living area that is accessory to the principal residence, located on the same lot, and that provides for sleeping quarters, kitchen, and sanitation facilities. An ADU may be internal, attached or detached."

• The distinguishing characteristic signifying an ADU for the county is a kitchen, even without an oven or stove. A guest or mother in law suite with just a bedroom and bathroom may not be subject to the same restrictions.
• An ADU must not exceed 1,000 square feet 
• There is a limit on the number of ADU permits available, so check with county before moving ahead. The number of detached ADU permits in any calendar year shall not exceed 12 percent of the total number of building permits for new principal residences issued for the previous calendar year. 
• In order to reduce impact, ADU's must be located within 100 feet of the principal residence. 
• Urban Growth Areas and Activities centers generally allow ADU's with less restrictions than rural zones
• A detached ADU is not permitted on parcels less than five acres in size in any rural district, 10 acres in size in the agricultural district, and 20 acres in size in the forest district. Visit the Assessor's Site to find out what zone you are in. 
• Within the Town of Friday Harbor, a detached guesthouse is not a permitted
  accessory structure in Single Family Zones. The Hare House, which is in town and includes a guest house, is in a Multifamily Zone.

 Example home plan, the Pearl Cottage, under 1,000 square feet

Our Home Plan Collection has some great floor plans and designs under 1,000 square feet. View the collection for ideas and inspiration-plans can be customized to meet your needs. 

Next Friday, we'll look at regulations for Bellingham, Anacortes, and Island County. 

 

ADU 101

Accessory Dwelling Units (ADU's) have become more popular and acceptable in the past few years. The City of Seattle began allowing for ADU's in all residential zones (it had previously been only some south Seattle neighborhoods) in 2009. San Juan County allows for a limited number of permits for ADU's each year.

An ADU can be attached, as in a basement apartment, or detached, as in a backyard cottage, carriage house, or alley flat. The implementation of ADU's can fulfill many goals of sustainable development, including density, affordable housing, and smaller house sizes. As our urban fabric is "re-knit", neighborhoods can become more dense, creating more demand for services, therefore creating more opportunities for walkable neighborhoods and less dependence on a car.

Truly sustainable development also includes social goals, many of which are also met by integrating ADU's: a way for homeowners to have a separate income stream, a mix of income and ages; the ability to stay in one neighborhood through varying phases of life, therefore creating lasting community: kids can live in a backyard cottage as they start on their career path, elderly parents or relatives can live in smaller spaces that require less upkeep and be close to their children and grandchildren. The term "mixed income" may be worrisome, but from a social standpoint, renting out an ADU can more successful than an absentee landlord renting a house, in that owners are close to the rental unit, tenants are close to their landlord, so each keeps an eye on each other. The Kentlands Development in Maryland (designed by New Urbanism pioneers DPZ)  is a neighborhood that has successfully integrated market rate, large suburban housing with backyard rental units. An often cited example is of a woman who lived in her ADU and rented out her large house in order to save money and pay off her mortgage.

Anna spoke to BUILDERnews magazine about the benefits of building an ADU or guest apartment. See the article, including photos of two of our projects that include these structures here.

Hare House in Friday Harbor, Second Floor Plan: an apartment over an office and garage can be used for family, or rented out for extra income.

Summaries of Seattle and King County's rules for Accessory Dwelling Units are below. In the coming weeks we will have summaries of the rules of other cities and counties.

Rules for Seattle ADU

View the Backyard Cottage Overview from the City of Seattle Department of Planning and Development here. 

From the overview:

Among those aware of a backyard cottage in their neighborhood:
• 71% said that the backyard cottage in their neighborhood fit in with the surrounding homes.
• 84% noticed no impacts on parking or traffic directly related to the backyard cottage.
• 83% were supportive or strongly supportive of backyard cottage policy.

Highlights from the Client Assistance Memo 116A, "Establishing an Attached Accessory Dwelling Unit (ADU)."

• Backyard cottages, also known as detached accessory dwelling units (DADUs) are allowed citywide effective Dec. 4, 2009
• Seattle Defines an ADU as: a room or set of rooms in a single family home that has been designed or configured to be used as a separate dwelling unit.
• A single family lot my have one ADU or Backyard Cottage.
• An ADU is limited to an area of 1,000 square feet in the single family structure. A unit in a single-family
  home may exceed the maximum size if the structure was in existence prior to June 1, 1999, and if the
  entire accessory unit is located on the same level.
• A parking space for the ADU is required unless it is located in a designated urban center or village, or if the topography of the site or structure location makes it "unduly burdensome."

Rules for King County ADU's

View a summary from the county with links to the code document (summarized below) here.  

• Accessory dwelling units are allowed in all zones in unincorporated King County except Mineral (M) and Industrial (I), provided that certain conditions are met.
• No separate ADU's are allowed on urban lots less than 5,000 square feet, a non-conforming rural lot, or a lot containing more than one
• Either the primary dwelling or the ADU have to be owner-occupied 
• Only one entrance can be located on the street side