Last month, Master Builders Association of Pierce County has formally submitted a Comprehensive Plan Amendment in Pierce County to change density calculations from “net” to “gross” in urban residential areas. This change would apply the allowed density to the entire site rather than applying it only to the area that is left over after deducting features such as roads, wetlands, and so on. Because residential zones include a requirement that subdivisions comply with both the minimum density and the maximum density, calculating density using Gross Site Area will achieve the following: predictability, simplicity, flexibility, and better infill potential.
Predictability- Gross density calculations will ensure that feasibility analysis, property transactions, and pre-application meetings will all be based on the same understanding of the lot potential. Furthermore, because many permits, utility connections, and impact fees are based on the number of lots created, it will be easier to understand upfront costs.
Simplicity- It will be far easier for the applicant and Pierce County Staff to understand the subdivision potential when using gross density calculations. The gross density calculation is a figure that is a known quantity from the beginning whereas net density calculations are not fully understood until well into the design process (as roads, critical areas, etc. are subtracted out).
Flexibility- Applicants and Pierce County can exercise greater creativity in designing lot and road layouts when working around wetlands, steep slopes, storm water ponds, and other constraints that exist on lots.
Better Infill Potential- One of the foundational goals of the Growth Management Act is to encourage growth within Urban Growth Areas to reduce sprawl in surrounding farm, forest, and open space areas. Net density calculations have reduced lot potential in various urban zones.
By adopting this amendment, land in the Urban Growth Area can be used more efficiently, maximizing the developable acreage available within the UGA, resulting in more efficient use of public utility infrastructure, reducing lot development costs and furthering efforts for attainable housing in Pierce County (all of which advance regional goals). For example, in areas within the County that have sewer, to accomplish the urban densities, we should be obtaining 6 units per acre. Current realized density is closer to 4.5 units per acre due to policies like Gross vs Net calculations.
The math required for such calculations that needs to continually be updated through the platting process adds unneeded complexity and time with no benefit provided to the public and contributes to the high cost of housing. The current net density calculations penalize available lands, even those without critical areas. This proposed change will not affect the amount, calculation, or the size of critical areas OR the protections of those lands.
Per Pierce County Planning and Public Works’ website, “the application period for the 2021 Comprehensive Plan Amendments closed on July 31, 2020. The applications received will be forwarded for consideration for initiation by the County Council prior to September 30, 2020. Please refer to the Guidelines document for additional information about the amendments, timelines and process.”