Trombe Wall Case Study — GreenHome Institute: Design, Construction, and Cost ($67/sqft)

Source: GreenHome Institute webinar/case study Data basis: Single residential project, passive-certified home

Key Cost Data

• Total installed cost: ~$7,500 (materials and labor combined)
• Wall dimensions: 7’ x 16’ = 112 square feet
• Implied cost per square foot: ~$67/sqft (calculated, not stated by source)
• Described as: “a modest premium” for energy and comfort benefits
• No separate cost breakdown for materials vs labor provided
• No payback period calculated in the source

Construction Specification

• Core: 8-inch (or thicker) core-filled masonry block on substantial foundation
• Optimal thickness range: 6–10 inches (near 45th parallel)
• Selective surface: Tinox metal sheet — reached surface temperatures 25–30% higher than high-performance black masonry paint
• Alternative coating: SOLKOTE HI/SORB-II paint
• Air gap: 3/4 to 2 inches
• Glazing: Triple-pane Zola windows
• Sealing and insulation: High-heat tape, expanding foam tape, open-cell foam, backer rod, caulk
• Surrounding wall: 2x10 framed wall with Intello fabric, cellulose, and 6” rigid wood-pulp insulation (Timber HP)

Context for Cost Comparison

For reference, generic masonry wall costs (HomeWyse, May 2026):

• Basic masonry wall: ~$34–47/sqft installed
• Concrete block wall: ~$15–20/sqft installed
• The Trombe wall premium over a basic masonry wall is roughly $20–30/sqft, covering the glazing system, selective surface, air gap detailing, and enhanced foundation

Limitations

• Single project — costs vary by region, materials, and labor market
• Premium specification (triple-pane, Tinox) may be higher than simpler Trombe designs
• No energy performance or payback data provided
• US-based but location not specified beyond “near 45th parallel”