Parking under Silverview buildings remains disputed as engineers, planners contest aquifer, cost and design risks

A central planning question at the Silverview appeals hearing was whether the applicant must put parking under the proposed apartment buildings where feasible under the Silverdale waterfront design standards — and if so, whether that is feasible on this site.

What was argued: applicant-side witnesses and the project’s architect said structured (under-building) parking is not feasible because site-specific subsurface conditions — including a shallow, artesian aquifer in the downslope area — make deeper excavation risky and costly. The county’s staff (Jeff Smith) testified that the applicant’s feasibility analysis addressed the design standards and that staff believes the applicant has justified using surface parking rather than structured parking in the current proposal. Opponents and some independent witnesses argued that other design choices (podium parking, narrower building footprints, or alternative foundation methods) could allow under-building parking and that nearby examples in Silverdale show that one level of structured parking is feasible in the area.

Seismic, elevator and pit requirements: expert witnesses emphasized that elevators used in multiunit buildings require a below-floor elevator pit (industry practice cited: a minimum ~4.0 ft pit below the lowest service floor), plus sump and drainage for hydraulic elevator systems. Architects and engineers said that elevator pits and required waterproofing add complexity and depth to below-grade work and therefore can reach into subsurface lenses that parties call aquifer or confining till. One county-contracted geotechnical expert (testimony in prior submissions and referenced in hearing) signaled an opinion that foundations that preserve a specified thickness of confining till (50% of the confining layer, as cited in hearing) mitigate the highest risks, but witnesses disagreed on whether the project’s proposed structural sections meet that margin.

Costs and feasibility economics: parties discussed industry estimates. The applicant provided feasibility material citing a per-stall cost figure (~$30,000 per stall in one consultant analysis), while other industry references and a contractor estimate range shown in the hearing suggested higher per-stall ranges (examples used in testimony: ~$63,000 per stall in a comparative estimate from a construction-cost source). The arithmetic shown in the hearing: at $30,000 per stall for 160 required stalls, the incremental cost would be about $4.88 million; higher per-stall estimates would multiply that differential and affect project viability. County staff told the examiner they reviewed the applicant’s market and feasibility analysis and considered it sufficient for the remand issues.

Design trade-offs: witnesses and counsel agreed on trade-offs. Putting parking below the buildings reduces surface parking and visible car headlights, and can align better with the design standard preference to “build up rather than out.” But under-building solutions tend to narrow unit configurations or change unit orientation (double-loaded corridors versus garden-style walk-ups), which affects unit design, views, and perceived quality of housing. Architects warned that some low-cost design workarounds (for example, elevated walkways or “balcony” circulation to reduce measured egress distance) produce poor residential design; others argued they can be used to meet life-safety code if carefully done.

What the hearing produced: testimony, cross-examination, and exhibits. No final policy change was adopted during the session; the Hearing Examiner will consider the evidence and issue a decision. The debate included testimony from the applicant’s architect and contractor estimates, county staff, independent architects and geotechnical consultants, and references to nearby developments (North Beach, Rivulet) used as comparables.

Ending
The Examiner’s decision will need to weigh technical geotechnical risk, elevator and excavation depth requirements, construction-cost estimates, and the Silverdale design standards’ direction to prefer building up over out. The record includes competing professional judgments on subsurface risk and on how to interpret “feasible” in the waterfront design chapter; the Examiner’s written ruling will determine whether structured parking is required, optional, or infeasible for the Silverview proposal.