Decarbonization Strategist.

Overview

Build a 5–15 year decarbonization roadmap for a single building (existing or new). Combine:

1. Operational carbon — envelope improvements, HVAC efficiency + electrification, hot water electrification, on-site renewables, off-site RECs.
2. Embodied carbon — low-carbon concrete, EPD-driven steel, mass timber substitution, retain-vs.-replace decisions on existing structure.
3. Regulatory mandate timeline — jurisdiction-specific deadlines (LL97 cap periods, Title 24 cycle, BERDO targets, AIA 2030 ratchet).
4. Incentive stack — federal IRA tax credits, state rebates, utility programs.
5. Phased capex sequencing — what to do this year, in 5 years, in 10 years.

Output is a roadmap memo in docs/decarbonization/ that the owner / sustainability consultant / energy modeler takes into the actual technical scopes (whole-building energy model, LCA, incentive applications).

This skill is strategic, not technical: it does not produce energy-model outputs, LCA reports, or final incentive calculations. It frames the sequence of decisions that carbonization-impact technical work will prove out.

Aligned with NYC LL97, Boston BERDO, Washington DC BEPS, CA Title 24 Part 6, CA SB 253, Vancouver ZEBP, AIA 2030 Commitment + SE 2050, SBTi Buildings, IRA, EPA Portfolio Manager + ENERGY STAR, EC3 / Athena / OneClick LCA / Tally.

When to use

Trigger on:

• Pasted owner OPR with a carbon, EUI, or net-zero target.
• Building baseline (existing EUI from Portfolio Manager / utility bills, OR new-construction modeled EUI from Title 24 / IECC compliance).
• Explicit asks: "decarbonization roadmap", "decarb plan", "LL97 strategy", "Title 24 path", "2030 Commitment plan", "embodied carbon plan", "electrification roadmap", "net-zero strategy", "BERDO path", "IRA stacking question".
• Hand-off from passive-house-tracker, leed-tracker, or resilience-check when the certification / resilience target requires a longer-horizon carbon plan beyond the certification scorecard.

Do NOT trigger for:

• Whole-building energy modeling (use sustainability consultant + energy modeler — IES VE, EnergyPlus, eQUEST, OpenStudio).
• LCA / embodied carbon detailed modeling (use LCA consultant + EC3 / Athena / OneClick LCA / Tally).
• Single-credit LEED / WELL / PHIUS scoring (use the respective tracker skill).
• Single-mandate compliance check (use jurisdiction-specific code skill — e.g., climate-zone-mapper for IECC).
• Incentive application drafting (use sustainability consultant + tax counsel for federal incentives).

Workflow

Step 1 — Bootstrap if needed

Check that docs/decarbonization/index.md exists. If not:

python scripts/init_decarb_workspace.py

Step 2 — Anchor the project context

Read docs/project.md if it exists. Pull:

• Building type + use (multifamily / office / retail / institutional / industrial / mixed). Determines mandate applicability and benchmark medians.
• Existing or new construction. Existing buildings face benchmarking + cap mandates (LL97, BERDO, BEPS). New construction faces code-cycle mandates (Title 24, IECC + state stretch).
• Square footage (gross, conditioned, by-use breakdown). Mandates often kick in at thresholds (LL97: 25,000 sf; BERDO: 20,000 sf in 2025, lower thresholds later).
• Jurisdiction + named AHJ. The mandate landscape varies sharply — see references/mandate_landscape.md.
• Baseline EUI (kBtu/sf/yr — site EUI for existing, modeled EUI for new). Source: EPA Portfolio Manager (existing); compliance model output (new).
• Owner targets — IRR / NPV thresholds, hard deadlines (LL97 Compliance Period 2 starts 2030), certification commitments (LEED Gold, PHIUS+, WELL v2), 2030 Commitment / SBTi.
• Capex tolerance + horizon — owner staying long-term vs. flipping; sale at year 5 vs. hold for 30 years drastically changes ROI calculus.
• Trigger event — pending major renovation, leasing turnover, equipment end-of-life, electrification mandate effective date, refinancing covenant.

Step 3 — Map applicable mandates

Use references/mandate_landscape.md. For the named jurisdiction, identify:

• Carbon-cap mandate (LL97 / BERDO / BEPS) — building-class-specific cap, compliance periods, fine schedule. Cite from references/ verbatim — do not recall caps from memory.
• Energy-code mandate (IECC + state stretch / Title 24 Part 6 / NYS ECCC / WSEC) — applicable at permit. New construction or major renovation triggers.
• Disclosure / benchmarking mandate (CA SB 253, NYC LL84/87, BERDO benchmarking) — annual reporting requirements.
• Resilience overlay (NYC LL126 façade, FEMA flood zone, Title 24 wildfire) — affects sequencing.
• Federal mandate (Executive Orders on federal building decarbonization, GSA P-100 sustainability requirements) — federal projects only.

For each mandate, document: applicable / not applicable, threshold met (Y/N), next deadline, fine exposure, available compliance pathways.

Step 4 — Build the operational carbon path

Use references/operational_carbon_pathway.md. The standard sequence:

1. Envelope — air sealing, insulation upgrade, window replacement / film. Baseline-load reduction ALWAYS comes first (avoids oversizing electrified equipment).
2. HVAC efficiency — controls, BAS optimization, recommissioning. Cheap, fast.
3. HVAC electrification — replace fossil-fired boilers / furnaces / DHW with heat pumps. The largest operational carbon move on most buildings; staging matters.
4. DHW electrification — heat-pump water heaters; large central systems may stage longer than space heat.
5. Cooking electrification — induction, electric ovens (multifamily, commercial kitchens); often last to electrify.
6. On-site renewables — rooftop PV, EV charging infrastructure (some grid-resilience overlap).
7. Off-site renewables — RECs / PPAs to close residual operational carbon. Acceptable as last lever, not first.

Document the project's sequence with phasing: now / 5 yr / 10 yr / 15 yr.

Step 5 — Build the embodied carbon path

Use references/embodied_carbon_pathway.md. The standard moves:

1. Build less / retain more. Refurbishment + adaptive reuse beats new construction on embodied carbon almost always.
2. Concrete — Portland-cement substitution (slag, fly ash, LC3); lower-strength specs where structural; CarbonCure / Solidia-treated.
3. Steel — EAF (electric arc furnace) over BOF (basic oxygen furnace); EPD-required spec; recycled-content targets.
4. Insulation — avoid HFC-blown foam; use EPS / mineral wool / cellulose; check GWP.
5. Mass timber — substitute for concrete / steel on appropriate spans; carbon-storage benefit + sequestration (LCA accounting matters).
6. Façade — aluminum recycled-content, low-carbon glass.
7. Interior finishes — health-product declarations (HPDs) + EPDs.

Document the project's embodied-carbon move set with phasing.

Step 6 — Stack the incentives

Use references/incentives_stack.md. For the project profile, layer:

• Federal IRA — §13301 (179D commercial deduction), §13303 (45L residential credit), §48 (Investment Tax Credit for renewables), §13501 (45Y/48E clean electricity), Domestic-content bonus, Energy-community bonus, Prevailing-wage + apprenticeship bonus.
• State — CA SGIP, NY NYSERDA, MA Mass Save, IL ComEd, etc. — varies sharply.
• Utility — local utility incentives for heat pumps, building decarbonization, BAS optimization.
• Carbon credit / offset markets — caution; not a substitute for direct reductions.

Cite incentive amounts from references/ — do not recall from memory. IRA provisions have changed multiple times since 2022 enactment; confirm current rates via IRS guidance.

Step 7 — Phase + sequence the capex

Use the templates in assets/decarb_roadmap_template.md. The phasing logic:

• Year 0 (now) — fast, no-regret actions: benchmarking submission, BAS optimization, controls / setpoints, lighting LED retrofit, low-cost air sealing.
• Year 1–3 — medium capex, high impact: envelope improvements, HVAC partial electrification, on-site PV start.
• Year 4–7 — major capex, mandate-driven: full HVAC electrification, DHW electrification, façade upgrade if BERDO / LL97 cap pressure.
• Year 8–15 — finishing moves: cooking electrification, cooking-load shifting, off-site PPA / RECs to close residual.

Sequence so that mandate deadlines are met with margin. NYC LL97 Compliance Period 2 (2030–2034) starts 2030; building-decarb capex needs 2–4 years of design + procurement + install + commissioning lead time.

Step 8 — Write the roadmap memo

Use assets/decarb_roadmap_template.md. The memo includes:

• Header — project, building profile, baseline EUI, owner targets, jurisdiction, date.
• Mandate landscape — applicable mandates with deadlines and fine exposure.
• Baseline + target EUI / carbon trajectory — table or chart description.
• Operational carbon path — sequenced moves with year, scope, capex range, kBtu/sf reduction.
• Embodied carbon path — sequenced moves (mostly relevant for new construction or major renovation).
• Incentive stack — applicable federal + state + utility programs with amounts (from references/).
• Phased capex schedule — table by year.
• Open questions for the energy modeler / LCA consultant / tax counsel / utility.
• Risk flag — regulatory landscape changes, pending legislation, technology cost trajectory.
• Disclaimers — strategic plan, not energy model or LCA.

Write to docs/decarbonization/<project-slug>-<YYYY-MM-DD>.md and append to docs/decarbonization/index.md.

Step 9 — Hand off

The roadmap is strategic. Hand off to:

• Energy modeler / sustainability consultant for whole-building energy model under proposed scope.
• LCA consultant for embodied carbon quantification.
• MEP engineer for system sizing under the proposed electrification path.
• Tax counsel for IRA + state incentive application strategy.
• Owner facilities + capex planning for phased capex inclusion in long-range plan.
• passive-house-tracker / leed-tracker / resilience-check for certification + resilience overlays.
• value-engineering-advisor if budget constraints challenge the roadmap.

Anti-patterns

• Never recall LL97 caps, BERDO targets, BEPS performance standards, or fine schedules from memory. Cite from references/mandate_landscape.md only. The 2024 amendments to LL97 (Article 321) restructured the cap formula; the 2026 BERDO performance period began Jan 2025; the 2025 Title 24 cycle starts Jan 2026. Regulatory landscape changes faster than this skill — verify last-verified date on every reference; if > 12 months, flag for re-verification.
• Never recall IRA tax credit amounts from memory. §13301 (179D), §13303 (45L), §48, §45Y, §48E rates and bonus eligibility (domestic-content, energy-community, prevailing-wage) have changed multiple times since IRA enactment (Aug 2022). Cite from references/incentives_stack.md and direct user to IRS guidance + tax counsel for application.
• Never present this skill's roadmap as a guaranteed compliance pathway. The roadmap names strategic moves and phasing; actual compliance is proven by the energy model, LCA, and final permit / benchmarking submission.
• Never recommend off-site RECs / offsets as a primary compliance strategy. They are last-lever residual closure, not first move. LL97 explicitly limits REC + offset substitution per Article 321; BERDO and other mandates similarly restrict.
• Never skip the "build less / retain more" check on embodied carbon. New construction's embodied carbon often dwarfs decades of operational carbon savings. This skill must explicitly evaluate refurbishment / adaptive reuse against new construction.
• Never recommend electrifying space heat without first reducing envelope load. Electrified equipment sized to a leaky envelope is oversized, expensive, and underperforms. Envelope first, then electrify.
• Never quote $/sf or $/MMBtu cost numbers from memory. Cost benchmarks (RSMeans, RMI Net-Zero Buildings cost data, NREL ATB) update annually. Direct user to current source.

Resources

• scripts/init_decarb_workspace.py — bootstrap docs/decarbonization/ and index.md.
• references/_provenance.md — pinned editions; regulatory landscape changes fast.
• references/mandate_landscape.md — jurisdiction-specific carbon mandates.
• references/operational_carbon_pathway.md — standard operational decarb sequence.
• references/embodied_carbon_pathway.md — standard embodied decarb moves.
• references/incentives_stack.md — federal IRA + state + utility incentives.
• references/phasing_patterns.md — common phasing patterns.
• references/aia_2030_sbti_targets.md — AIA 2030 Commitment + SBTi.
• assets/decarb_roadmap_template.md — roadmap memo template.