Local Law 97 Compliance Retrofit Planner

Why Local Law 97 Planning Matters Now

New York City’s Local Law 97 sets aggressive carbon caps for buildings over 25,000 square feet, with penalties reaching $268 per metric ton of CO₂ above the permitted threshold. The first compliance period began in 2024, but the most stringent limits arrive in 2030. Waiting until the last minute risks costly fines, rushed retrofit contracts, and limited access to incentives. This calculator helps property managers, co-op boards, and energy consultants translate emissions limits into actionable retrofit plans. By comparing baseline intensity against future thresholds, you can see whether envelope upgrades, electrification, and renewable energy purchases will close the gap or if additional measures are required.

Many building owners rely on simple spreadsheets or vendor proposals that focus on energy savings alone. Local Law 97 requires a carbon lens: electrification can reduce on-site emissions but may raise electricity consumption, and offsets such as renewable energy credits (RECs) have limited applicability. The Retrofit Planner combines energy and carbon accounting while also surfacing financial impacts so decision makers can balance compliance with affordability. It handles both electric and fuel energy streams, applies user-defined emission factors, and calculates whether RECs or other clean energy purchases can bridge the final compliance gap.

How the Model Computes Compliance

The tool first calculates baseline emissions using the intensity you provide. Gross floor area multiplied by baseline intensity yields total kilograms of CO₂-equivalent. Converting to metric tons provides a reference point for penalties. It then compares this baseline to the allowed emissions for the compliance year, which equal the target intensity times the same floor area. The difference highlights how far the building must reduce to avoid fines. Next, the tool estimates post-retrofit emissions by applying projected energy savings and renewable purchases to your current energy usage.

Electricity savings reduce both cost and emissions. Fuel savings, often from boiler retrofits or heat pump conversions, cut natural gas or oil usage. Renewable purchases are credited against electric consumption, reflecting the city’s allowance for RECs sourced from Tier 4 projects. The core equation governing post-retrofit emissions is shown below.

Here, represents baseline electricity use, is projected electric savings, is renewable energy credit volume, is the electric emission factor, is baseline fuel use, is projected fuel savings, and is the fuel emission factor. The expression assumes RECs offset electric load first. Negative values are prevented by clamping energy terms to zero so the model never credits more savings than physically possible.

After calculating post-retrofit emissions, the tool converts them into intensity (kg per square foot) and compares the result to the target. Any excess translates into penalties using your specified rate. Energy savings also feed into financial metrics: electric savings multiplied by your electricity rate plus fuel savings multiplied by the fuel rate yield annual utility cost reductions. Adding maintenance savings captures efficiencies like reduced boiler servicing or fewer emergency repairs. Net annual benefit equals the sum of energy and maintenance savings minus any remaining penalties. Simple payback divides the capital cost by the annual net benefit, while the carbon payback years show how long it takes to offset the embodied emissions of the retrofit if you enter a proxy such as 50 kgCO₂e per $1,000 of investment.

Worked Example

Consider a 220,000 square foot multifamily building with a baseline intensity of 9.8 kgCO₂e per square foot, exceeding its 2030 limit of 4.07 kgCO₂e. The building consumes 3.2 million kWh annually at an emission factor of 0.29 kg/kWh and pays $0.21 per kWh. Boilers burn 210,000 therms with a factor of 5.31 kg/therm and cost $1.20 per therm. Engineers propose a heat pump retrofit that will save 1.1 million kWh and 140,000 therms, plus targeted envelope sealing worth 80 RECs (80,000 kWh). Maintenance savings are estimated at $85,000 annually, the capital plan totals $5.8 million, and the penalty rate remains $268 per metric ton. Entering these figures shows post-retrofit emissions drop to roughly 1,020 metric tons, below the 895 metric ton limit but within striking distance. Annual penalties vanish, utility savings top $1.1 million, and the simple payback falls just under five years—useful data for co-op shareholders weighing special assessments.

Scenario Comparison Table

The following table illustrates how incremental measures stack together for the example building.

Package	Emissions Intensity	Annual Penalty	Annual Net Benefit	Simple Payback
Do nothing	9.8 kg/sq ft	$1.25M	- $1.25M	n/a
Boiler tune-up only	7.5 kg/sq ft	$620k	$190k	14 years
Heat pump + envelope	4.6 kg/sq ft	$0	$1.19M	4.9 years

Seeing each package quantified helps boards justify deeper retrofits instead of incremental fixes that still miss the limit. Documenting penalties in the same table as energy savings reframes Local Law 97 conversations from optional upgrades to mandatory compliance strategies.

Linking to Related Planning Tools

Use this planner alongside the building-embodied-carbon-calculator.html when evaluating shared systems or steam loop conversions. If electrification is on the table, combine results with the heat-pump-operating-cost-estimator.html to understand load shifts on your electric tariff. For financing conversations, the renovation-loan-payment-calculator.html can model loan amortization relative to the net benefits calculated here.

Limitations and Assumptions

The calculator assumes all RECs directly offset electric load, aligning with current guidance but subject to change. It treats emission factors as static even though New York’s grid is greening; consider updating the electric factor for later compliance years. The model does not account for peak load implications or demand charge changes, which could matter for multifamily buildings with high plug loads. Likewise, it ignores capital incentives such as NYSERDA grants or federal tax credits that shorten payback. Finally, the simple payback metric does not incorporate discount rates or inflation; use more sophisticated financial models for investment-grade decisions.

Despite these caveats, the Retrofit Planner offers a transparent, defensible approach to Local Law 97 strategy. Revisit the analysis annually as utility rates, emission factors, and tenant loads change. Pair the quantitative insights with stakeholder engagement to ensure residents understand both the climate benefits and the financial realities of the chosen retrofit path.