Design review OK'd for 8,800 sq ft hillside home on Spring Hill Road with tree mitigation and engineered drainage

Lafayette's Design Review Commission voted unanimously to approve a phase‑2 hillside development permit on April 13 for a new primary residence at 3535 Spring Hill Road, adopting the staff recommendation and conditions.

Project planner Nicole ZL reviewed the application (ADP05‑26/GR09‑26/TP20‑26), saying the project proposes an 8,837‑square‑foot two‑story main house with a detached ADU and pool house, a maximum height of 33 feet and limited on‑site grading (about 1,100 cubic yards of cut balanced with 1,100 cubic yards of fill). Nicole indicated the house will be sited in a previously disturbed, lower‑slope area and is not visible from off‑site homes due to existing vegetative screening. She told the commission the applicant proposes to remove five trees (four listed as protected) and plant 26 new native trees on site as mitigation.

Owner Eric Williams and project designer Mark Becker described the team's effort to preserve the site's natural character and to employ fire‑wise building and landscape strategies. Becker said the team prioritized reducing risky roof connections, using noncombustible materials where appropriate, and siting circulation and plantings to reduce fire exposure. Nicole and the design team added a project‑specific condition that the fire district must approve any alternative materials and methods for fire protection before construction.

Civil engineer Angelo (CBG) explained the drainage approach: conveyance down a dry corridor into a series of retention basins with overflow control so post‑project runoff is equal to or less than existing flows. The basins are designed to be dry most of the year but to attenuate peak flows during storms via orifice plates and controlled outlets.

Neighbor Doug Del, the closest resident, voiced support and praised the team's outreach and attention to drainage, while acknowledging that lower neighbors may experience any failures in conveyance and that engineering follow‑through is essential.

The commission praised the architecture and materials—several commissioners singled out slate roofing and the restrained palette—and endorsed the applicant's tree replacement and drainage strategy. The commission approved the staff recommendation to find the project exempt from CEQA and adopted DRC resolution 20263 on a 3–0 voice vote. Conditions include final engineering review, fire district approval of proposed alternative materials/methods and protections for newly planted and existing protected trees.