/epd-compare
Side-by-side environmental impact comparison with LEED MRc2 check
What it does
Type /epd-compare with products to compare — from parsed EPDs, research results, sheet references, or pasted data. The skill validates comparability (declared units, system boundaries, PCR alignment), generates side-by-side impact tables, calculates percentage deltas relative to the lowest-impact option, and checks LEED v4.1 MRc2 eligibility.
Install
Claude Desktop:
- Open Customize → Browse plugins
- Click + → Add marketplace from GitHub
- Enter
AlpacaLabsLLC/skills-for-architects - Install the Sustainability plugin
Claude Code (terminal):
claude plugin marketplace add AlpacaLabsLLC/skills-for-architects
claude plugin install 05-sustainability@skills-for-architectsOr symlink just this skill:
git clone https://github.com/AlpacaLabsLLC/skills-for-architects.git
ln -s $(pwd)/skills-for-architects/plugins/05-sustainability/skills/epd-compare ~/.claude/skills/epd-compareUsage
After parsing or researching EPDs:
/epd-compare compare the CLT EPDs I just foundOr with inline data:
/epd-compare concrete A: 320 kg CO2e/m3, concrete B: 280 kg CO2e/m3, concrete C: 410 kg CO2e/m3What it checks before comparing
- Declared unit alignment — warns if units differ and normalization isn’t possible
- System boundary — flags cradle-to-gate vs. cradle-to-grave mismatch
- PCR alignment — notes when products use different Product Category Rules
- EN 15804 version — flags +A1 vs. +A2 differences (AP/EP units may differ)
- Validity — marks expired EPDs
- EPD type — distinguishes product-specific from industry-average
Sample: CLT comparison
Generated from: three CLT EPDs (Stora Enso, Arboreal, Kalesnikoff)
Comparability check: ✓ Declared unit: All 1 m3 ✓ All product-specific, third-party verified ⚠ System boundary: Stora Enso cradle-to-grave, others cradle-to-gate — A1-A3 comparison valid ⚠ Standard: Stora Enso & Arboreal EN 15804+A2, Kalesnikoff ISO 21930 — GWP comparable ⚠ Biogenic carbon: Use GWP-fossil for fair comparison across CLT producers
| Metric | Stora Enso | Arboreal | Kalesnikoff | Unit |
|---|---|---|---|---|
| GWP-fossil (A1-A3) | 52.6 | 111 | 124.5 | kg CO2e/m3 |
| GWP-biogenic (A1-A3) | -762 | -857 | — | kg CO2e/m3 |
| GWP-total (A1-A3) | -708 | -743 | 124.5 | kg CO2e/m3 |
| PENRE (A1-A3) | 816 | 1,700 | 2,352 | MJ/m3 |
GWP-fossil (relative to lowest): Stora Enso — baseline · Arboreal +111% · Kalesnikoff +137%
Recommendation: Stora Enso is the clear leader on fossil GWP — less than half of the North American alternatives. For North American projects, Kalesnikoff has a shorter supply chain. All three qualify for LEED MRc2 Option 1 and Option 2.
Output saves as a markdown comparison report.
Pairs with
/epd-parser— parse EPD PDFs to get data for comparison/epd-research— find more EPDs to compare/epd-to-spec— use the lowest GWP from the comparison as a spec threshold