# Addition permit BLD-SFD2025-00089 at 665 Maxwell Ave, Boulder

Boulder Planning and Development Services permit BLD-SFD2025-00089: issued Oct 27, 2025 for addition work at 665 Maxwell Ave. The project involves renovating the existing basement and adding an 80-square-foot rear entry. The basement floor will be excavated approximately three feet to achieve a 10-foot ceiling height, requiring foundation reinforcement. The electrical panel will be relocated, and the existing HVAC system will be replaced with an electric heat pump and a gas air handling unit, to be design-build. COB additional description - scope includes excavation of existing crawl space (approximately 271 sf) under north end of dwelling, approximately 7 feet to match proposed excavation depth in the existing basement (approximately 670 sf). Proposed basement plan to include 1 bedroom/office, 1 bathroom, storage/mechanical area, living room / family room, and wet bar. Expansion of existing basement window openings and new window wells for egress.

- Permit number: BLD-SFD2025-00089
- Issued: Oct 27, 2025
- Type of work: Addition (city: Building Permit - Single Family Detached Dwelling, Addition and Alteration)
- Status: Issued (city: Issued)
- Reported cost: $225,500
- ZIP code: 80304
- All permits at this address: https://nearbypermits.com/boulder/address/665-maxwell-ave/

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Source: Boulder Planning and Development Services permit data (https://www.arcgis.com/home/item.html?id=e3ff6248e4a547bcba31025d2c5c9fee). Checked 2026-10-07 12:26 UTC. Nearby Permits, https://nearbypermits.com. JSON API and MCP server: https://nearbypermits.com/developers/

Every permit at 665 Maxwell Ave: https://nearbypermits.com/boulder/address/665-maxwell-ave/