07 · Building Envelope
Status: Planned
The building envelope — the physical separator between the conditioned interior and the exterior — is one of the most complex coordination points in this project. It must integrate the solar roof, structural steel, existing stucco walls, and interior finishes into a continuous weather, thermal, and fire barrier.
Envelope components
The current concept includes:
- Roof: Standing-seam metal over self-adhered underlayment on metal deck (713 sq ft main + 131 sq ft hip cap)
- Wall assembly (inside existing stucco): Metal stud framing, R-19 batt insulation, 6-mil vapor barrier, 5/8″ Type X drywall (fire code), interior metal panels
- Interior metal panels: 2″ insulated metal panels, 665 sq ft net
- Openings: North loading door, west door, 3 north windows, balcony sliding door
Coordination challenges
- Thermal bridging: The steel frame penetrates the envelope at every column. Each penetration needs thermal break detailing.
- Moisture: Existing stucco walls must be evaluated for water intrusion before enclosing them behind new insulation and panels
- Fire separation: The Type X drywall requirement comes from fire code; the exact fire separation distance to property lines determines the assembly rating
- Ventilation: An enclosed space above a garage needs mechanical or natural ventilation per code
- Solar roof integration: The standing-seam metal roof must accommodate PV panel mounting without compromising the waterproofing
Design decisions needed
- Roof drainage plan (gutters and downspouts, or alternative)
- Condensation management strategy
- Vapor barrier placement (climate zone determination)
- Flashing details at all steel column penetrations
- Hip cap transition detailing
- Exterior-grade door and window specifications