Environmental consumption data is measured. But is it accurate?

By Stuart Cox ,

Chief Commercial Officer, Praysio

The property industry accepts that design stage models are a poor guide to a building's environmental performance. Innovate UK's Building Performance Evaluation Programme monitored fifty non-domestic buildings, twenty five of them BREEAM Excellent or Outstanding on paper, and found the average emitted 3.8 times the carbon estimated at design stage. [1] Only one came close to matching its prediction.

The response has been to move towards operational data. I believe this was the right move, but it brought an unintended consequence. Modelled data is now treated with scepticism, whilst metered data is treated as gospel and used as the foundation for ESG reporting.

But can you be sure this data is right?

What the Meter Never Saw

The underlying assumption is that a building's metering estate is complete. In most multi-tenanted buildings we have encountered, nobody has checked. A data centre in the basement pulling power straight off the landlord supply with no meter of its own. A rooftop solar array with nothing sub-metering self-consumption against export. Tenant load tapped off a rising busbar with nothing downstream to record it. Heat meters that appear on the BMS and the as-built drawings but cannot be found on site.

The dashboard shows a number, it is recorded and processed, and it works its way into the annual report. The consumption that was never metered is not in the figure, and nothing flags its absence.

Where meters do exist, the second question is what they can actually tell you. A single incoming supply meter reports the building total, so consumption is apportioned by floor area: the tenant running servers overnight pays the same rate per square metre as the one whose team leave at five. Monthly readings show consumption rose, but not why. Half hourly data at demise level shows a spike at three in the morning, and which tenant it belonged to. That is actionable data for a property manager.

The Rating Inherits the Gap

An EPC rating provides a notional model of the building. BREEAM and LEED assess design and construction, and do not come back five years later to check the metering estate is still reporting correctly. NABERS UK is the exception, built on twelve months of actual metered consumption, which is also why it carries a particular risk. Every gap identified above passes straight through, without anyone knowing it is there. A rating derived from real data is trusted more than a modelled one, which makes the gaps underneath it more consequential.

Where the Liability Sits

The failure to prevent fraud offence under the Economic Crime and Corporate Transparency Act 2023 came into force in September 2025. It applies to large organisations, which captures most landlords and managing agents, and the defence is having had reasonable procedures in place. An inaccurate ESG figure is not fraud. But describing a figure as measured is a representation about how it was produced, and defending it means showing the process.

This is where much of the sector would struggle. Manual readings transcribed into spreadsheets, with an incomplete audit trail back to a physical meter, are hard to stand behind as a reasonable procedure. If a reading cannot be traced to a specific meter serving a specific demise, there is very little left to demonstrate.

Getting the Foundation Right

At Praysio we treat metering data as the foundation of the energy tech stack. Tenant recharge, ESG reporting and net zero planning all sit above it. It is why we produce a Utilities Management Document: a walked survey of every network, meter and generation asset, traced back to source and checked for MID compliance and condition, with a record of who is being recharged for what. That is what is on site today, not a desktop review of drawings from the 1990s.

Tenants can query a bill and get an accurate answer. For a portfolio manager it is confidence in the meter data sitting underneath the ESG return. And when a building comes to transact, the new owner knows what is connected and what is metered, with an accurate record of ESG data and no nasty surprises.

The commercial property sector has spent a decade learning to be sceptical of modelled building data. How much scrutiny have we applied to the metering infrastructure we are now reliant on?