Affordable Housing Regulations

When does this apply?

Compliance with the Mandatory Affordable Housing Program is required for all new residential projects. New residential projects are those that build housing where there is currently none, such as for a new subdivision or construction on a vacant lot. For a project that includes rebuilding a house to replace a demolished one, this Program would not apply. (SMC 21.10.020)

What is 80% AMI?

AMI stands for Area Median Income, as most recently determined by the Housing and Urban Development (HUD). Sammamish is part of the Seattle-Bellevue Metro Fair Market Rent (FMR) Area. More information can be found on the HUD User Portal.

Can I pay an in-lieu fee?

For constructing a new house on a vacant lot, an in-lieu fee can be paid instead of restricting the new house as an affordable unit at 80% AMI. The in-lieu fee is $34.45 per square foot of living space in the residence.

However, for a subdivision, the number of required affordable units is determined by rounding up from one-half to the nearest whole number. (SMC 21.10.030.C)

Can I do off-site construction or land dedication?

Construction of affordable housing off-site may be allowed if it does not result in an undue concentration of affordable housing in the City. Priority is given to sites within 0.25 miles of the project site, and approval must be prior to the issuance of building permits for the project. The intent is for affordable housing units to be provided before or at the same time as the on-site market rate housing.

Land dedication would be part of a Development Agreement between the applicant and the City. The Development Agreement must be adopted by City Council prior to the issuance of building permits for the project. (SMC 21.10.060)

New Single-Family House Example

Construction of a new single-family house on a vacant lot. The new house will be 3,5000 square feet.

One house = 1 unit

1 unit x 10% = 0.1 mandatory affordable units

Option 1: designate the house as affordable at 80% AMI

Option 2: pay in-lieu fee (3,500 sqft. x $34.45/sqft = $120,575)

New Single-Family House with Accessory Dwelling Unit (ADU) Example

Construction of a new single-family house with an ADU on a vacant lot. The new house will be 2,500 square feet and the ADU will be 1,000 square feet.

The ADU will not be part of the calculation, since it is not bigger than 1,000 square feet.

1 unit x 10% = 0.1 mandatory affordable units

Option 1: designate the house as affordable at 80% AMI

Option 2: pay in-lieu fee (2,500 sqft. x $34.45/sqft = $86,125)

Four Unit Example

A project will build four new homes of 3,000 square feet each, for a total of 12,000 square feet.  

4 units x 10% affordable = 0.4 mandatory affordable units

Option 1: designate one house as affordable at 80% AMI

Option 2: pay in-lieu fee (12,000 sqft. x $34.45/sqft = $ 413,400)

Six Unit Example

A project will build six new homes of 3,500 square feet per home, for a total of 21,000 square feet.

6 units x 10% affordable = 0.6 mandatory affordable units, which must be rounded up to 1.0

Only option: designate one house as affordable at 80% AMI

Fourteen Unit Example

A project will build 14 new homes with an average of 3,500 square feet per home for a total of 49,000 square feet.

14 units x 10% = 1.4 mandatory affordable units

Option 1: designate one house as affordable at 80% AMI (this satisfies the affordable housing requirement for the first 10 homes);

then in-lieu would be paid on the remaining 4 homes, calculated at the average size of all the homes

4 x 3,500 sqft. = 14,000 sqft.        14,000 sqft. x $34.45/sqft = $482,300

Option 2: designate one house as affordable at 50% AMI, which is equal to two 80% AMI units, then the entire affordable housing requirement is satisfied

Option 3: designate two houses as affordable at 80% AMI, then the entire affordable housing requirement is satisfied