37% of parking spaces in new Seattle multifamily buildings sit empty at peak hours due to outdated demand assumptions baked into construction decisions

An analysis of 23 recent Seattle-area multifamily developments found that 37% of built parking spaces were unoccupied even during peak evening hours, meaning developers spent tens of millions constructing structured parking that sits permanently underutilized. With structured parking costing $25,000-$50,000 per above-ground space, this represents hundreds of millions in wasted capital across just one metro area. Why it matters: Empty parking spaces still carry mortgage, maintenance, lighting, and insurance costs that are bundled into tenant rents, so residents effectively pay $100-$250/month for parking they may not use, so buildings become less competitive on price compared to what they could offer, so the urban land consumed by unnecessary parking structures cannot be used for additional housing units or commercial space, so the opportunity cost compounds across every new development in a housing market already short hundreds of thousands of units. The structural root cause is that parking demand projections used by developers and lenders are based on ITE Parking Generation rates derived from suburban, auto-dependent sites measured decades ago. Lenders typically require developers to meet or exceed these ratios as a condition of financing, creating a structural over-supply independent of actual tenant car ownership rates, which in transit-rich urban areas can be 30-50% lower than suburban benchmarks.