Outlook: Partly sunny, future uncertain
The average density of new residential development in north county urban areas has increased since the late 1990s and exceeds the 2035 target. However, average density in urban centers, corridors, and infill areas has decreased and remains below the 2035 target.
The average density of new residential development between 2015 and 2035 will be above 7 dwelling units per acre in urban areas as a whole, and above 15 units per acre within Lacey, Olympia, and Tumwater’s urban centers and corridors.
Lacey, Olympia, Tumwater, and Yelm are within Intercity Transit’s service area. In order to make efficient use of the region's significant investment in transit, local land use plans encourage new growth to be at transit-supportive densities. The rule of thumb: 7 dwelling units per acre is the minimum density needed for transit service, and 15 units per acre (along with a mix of jobs and activities) is needed to support frequent transit service (service every 15 minutes or less).
What are we measuring?
Average density of new residential development (new homes per residential acre).
After the passage of the Growth Management Act (GMA) in the early 1990s, local cities and Thurston County increased zoning densities (the number of dwelling units required per acre) in areas designated for urban growth, which includes the cities and their adjacent Urban Growth Areas (UGAs). The cities also increased densities in urban centers and corridors. The results were mixed: While this led to an increase in residential density in the urban areas overall (with the exception of several small urban areas without urban infrastructure, such as sewer), there has been little residential activity within the north county centers and corridors, and what has occurred has not averaged very high densities.
This has led to Lacey, Olympia, and Tumwater re-examining zoning and incentives in their centers and along the commercial areas of the corridors. The next step is to re-examine zoning in neighborhoods adjacent to corridors. Jurisdictions could allow more homes in these neighborhoods by providing opportunities for “middle density” — such as granny units, duplexes, and small apartments — without changing the character of the neighborhood. Such density will not only support transit, but it will also support businesses that can create neighborhood hubs.
Housing Types and Characteristics (PDF)
Understanding what density measures mean in relationship to local buildings can be difficult. This document shows that transit-supportive density does not have to be achieved by high-rise apartments.