Most Local Law 97 metering conversations are about electricity. That made sense for the first compliance period. It stops making sense in 2030, and the reason is a single line in the rule book.
The coefficient that halves
Local Law 97 converts energy use into tonnes of CO₂e using fuel-specific coefficients set in 1 RCNY §103-14(d)(3)(ii). Those coefficients change for the 2030–2034 compliance period, and they do not change evenly.
| Fuel | 2024–2029 | 2030–2034 | Change |
|---|---|---|---|
| Grid electricity, tCO₂e/kWh | 0.000288962 | 0.000145 | −49.8% |
| Natural gas, tCO₂e/kBtu | 0.00005311 | 0.00005311 | none |
| District steam, tCO₂e/kBtu | 0.00004493 | 0.00004320 | −3.9% |
| Fuel oil #2, tCO₂e/kBtu | 0.00007421 | 0.00007421 | none |
Figures as presented in the NYC Department of Buildings webinar LL97: Calculating Building Emissions & Emission Limits, 26 June 2024.
The city is crediting the expected decarbonisation of the grid. Electricity gets cleaner on paper whether or not a building does anything. Gas does not.
Per MMBtu, the ranking inverts
Penalties under LL97 run at $268 per tonne of CO₂e over the limit. That converts each unit of energy avoided into a dollar value.
| Unit saved | 2024–2029 | 2030–2034 |
|---|---|---|
| 1 kWh | $0.0774 | $0.0389 |
| 1 therm | $1.423 | $1.423 |
Normalise both to site energy and the picture flips:
| Per MMBtu saved | 2030–2034 |
|---|---|
| Electricity | $11.38 |
| Natural gas | $14.23 |
Before 2030, a MMBtu of avoided electricity is worth about 59% more than a MMBtu of avoided gas. From 2030, a MMBtu of avoided gas is worth about 25% more than electricity. Same building, same meter, opposite conclusion — driven entirely by the coefficient change.
The practical consequence: a metering system that measures only electricity is instrumented to optimise the lever that is about to lose half its value. Every kWh it helps you avoid is worth half as much in 2030 as it is today. The therms it cannot see are worth exactly what they were.
The hardware the code already requires is the hardware this needs
This is the part worth sitting with if the building is new construction in New York.
The 2025 Energy Conservation Construction Code of New York State took effect 31 December 2025 with no transition period. It is based on the 2024 IECC, and Section C405.13 applies at 10,000 square feet of gross conditioned floor area. Unlike the 2021 edition, C405.13.8 requires submetering of non-electrical end uses — gas, fuel, and district energy.
So a new covered building in New York is already obliged to install a gas measurement channel. That channel is not a sustainability nice-to-have. It is the instrument that tells you where your 2030 exposure actually sits.
Buildings that treat C405.13.8 as a box to tick get a gas pulse output wired to nothing useful. Buildings that treat it as the start of a 2030 position get a gas consumption record from day one.
What metered data does and does not do under LL97
It is worth being precise here, because overstating it is easy and an engineer will catch it.
Interval metering is not required to file. A building can report annual utility consumption against the default coefficients and that is a compliant filing. Anyone who tells you LL97 mandates submetering is wrong.
What hourly, submetered data opens up:
- Time-of-use electricity coefficients — §103-14(d)(3)(iii)(b). Hourly consumption data lets electricity be valued against when it was actually used rather than a flat annual factor.
- Metered beneficial electrification — §103-14(d)(4)(iii)(a). A deemed route exists without metering for equipment below 1,200,000 Btu/h; above that, measurement is the route.
- Campus time-of-use, distributed generation and storage — §103-14(d)(3)(vi).
- Six-year record retention — §103-14(b)(1). Worth noting that this is twice the energy code's 36-month requirement. If a monitoring arrangement is being written, it should be written to the longer obligation, not the shorter one.
The honest version of the argument is this: metering is what lets you file the favourable way, and it is the only way to find the reductions you will need by 2030. It is not what lets you file at all.
How much of the exposure is still ahead
Urban Green Council, analysing 2024 energy data, found that roughly 9% of covered properties exceeded their 2024 cap while roughly 57% exceeded their 2030 cap. That is an analysis by a policy organisation rather than a City figure, and worth citing as such — but the shape of it is the point. The first compliance period caught a minority of buildings. The second catches most of them, and it is the period in which gas becomes the expensive fuel to waste.
What this means for specification
For a new or substantially altered covered building in New York:
- Specify the C405.13.8 gas channel as a measurement point, not a compliance artefact. A pulse output from the gas meter into a data concentrator costs very little more than a pulse output into nothing.
- Two pulse inputs on a typical gateway will not carry gas plus water. If both are in scope, a pulse or Modbus concentrator belongs in the design.
- Size record retention to six years, not 36 months.
- Treat the electric channels as the near-term lever and the gas channel as the 2030 lever. Both are needed; they pay off in different compliance periods.
Emergent Metering supplies the measurement hardware for this — gas meters and pulse outputs, current transformers, electric submeters, concentrators and gateways, and the enclosures they sit in.
Frequently asked questions
Does Local Law 97 require submetering? No. Annual utility consumption reported against the default coefficients is a compliant filing. Submetering enables the alternative calculation methods in §103-14 and is how reductions get found, but it is not a condition of filing.
Why does the electricity coefficient drop and the gas coefficient stay flat? The coefficients anticipate grid decarbonisation. Grid electricity is expected to carry less carbon per kWh by 2030, so the rule credits that. Combustion of natural gas on site produces the same emissions regardless of what the grid does, so there is nothing to credit.
Does saving water help an LL97 position? No. Emissions from treating and delivering water sit with the water utility, upstream of the building. Water savings are worth real money on the water and sewer bill, but they do not move a building's LL97 number by a single tonne.
What are the LL97 penalties? $268 per tonne of CO₂e over the annual limit, and $0.50 per square foot for failing to file. Reports are due 1 May with a grace period to 30 June. The law covers most buildings over 25,000 square feet.
Which buildings must install non-electrical submetering? Under the 2025 ECCCNYS, new buildings at or above 10,000 square feet of gross conditioned floor area fall under C405.13, and C405.13.8 extends the requirement to non-electrical end uses. Confirm scope for your specific project against the adopted code text.