Measuring up: M&V for the decarbonisation era
As featured in EIBI · Energy Institute CPD
Measuring up: M&V for the decarbonisation era
How to prove that energy and carbon savings from heat pumps and retrofits are real, measured and attributable.
Decarbonisation changes what we need to prove. A heat pump that replaces a gas boiler doesn't just cut kWh — it switches fuel, runs differently, and can look good on paper while underperforming in practice.
Hilary's CPD module for EIBI sets out how Measurement & Verification (M&V) shows whether savings are real, measurable and attributable to the measures taken, rather than assumed. Here are the key points for anyone commissioning, funding or signing off an energy efficiency or decarbonisation investment.
Key takeaways
Five takeaways for estates and energy teams
Savings can't be metered — only shown against a counterfactual
M&V compares what you actually used with a modelled business-as-usual case: what you would have used without the measure.
So what?If your business case doesn't say how that baseline is built, your savings figure is open to challenge.
For electrification, carbon is the comparison — not kWh alone
Swapping gas for electricity changes the unit that matters. Comparing kWh before and after can mislead.
So what?Agree up front whether you're reporting energy, cost or carbon, so payback and value for money are judged on the right basis.
One COP reading tells you little — Seasonal Performance Factor tells you more
SPF is measured over a full heating season and reflects real operation. It only means something when it's quoted with its measurement boundary.
- H1Heat pump unit only
- H2+ source-side fans or pumps
- H3+ backup heaterMeter separately
- H4+ building-side fans or pumps
Each boundary includes everything in the one before. Source: SEPEMO-Build project.
So what?Meter the backup heater separately and check commissioning early. A system running hotter than necessary is a common, easily missed fault.
Choose the IPMVP Option to fit the decision
Option A is quick but relies on assumed demand. Option C uses utility data you already hold but picks up every change on site. Option D suits new buildings with no baseline.
So what?The right Option depends on what you need to prove, and to whom. Compare the four Options in our guide →
Track changes and state uncertainty — or expect disputes
Routine adjustments (weather, occupancy) and non-routine events (floor area, plant changes) both need a clear process. Uncertainty from models, meters and sampling should be weighed against the expected saving.
So what?Most savings disputes come down to gaps in the M&V Plan that could have been closed at the start.
A heat pump can look good at H1 and still disappoint at H3/H4 if the backup heater is doing too much work.
Hilary Wood PMVE · writing in EIBI
Applying it
What this means for your organisation
If you're investing in heat pumps, a PSDS-funded scheme or a RE:FIT programme, M&V is how you show funders, boards and auditors that the investment delivered. Ongoing measurement also catches underperformance early, while it can still be fixed.
Whether you're buying an energy efficiency or decarbonisation scheme or delivering one, agree the baseline, boundary and reporting unit before the measure goes live.
FAQs
Frequently asked questions
How do I prove a heat pump has saved carbon?
Build a weather-normalised baseline of the gas that would have been used. Subtract any residual gas and the heat pump's electricity, converted to carbon. Measure over a full heating season.
What is the difference between COP and SPF?
COP is a snapshot under set conditions. SPF is measured over a heating season and reflects real operation, so it is the better guide to actual performance.
Which IPMVP Option is best for a hospital or university?
Multi-measure, whole-site programmes often suit Option C. Single measures where demand is hard to isolate may suit Option A or B. It depends on the metering available and what must be proven.
Can IPMVP use assumed values?
Option A allows some parameters to be estimated, provided the key parameter is measured and the estimates are justified in the M&V Plan.
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EEVS has been independently measuring and verifying savings since 2011. M&V is all we do.
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This article summarises a CPD module first published in Energy in Buildings & Industry (EIBI), October 2026. IPMVP® is a registered trademark of the Efficiency Valuation Organization (EVO).