No. A certified Energy Performance Certificate must be produced by an accredited assessor using approved software such as SAP or SBEM. This tool gives an operational-energy-intensity indication based on actual consumption, useful for screening but not valid for legal or transaction purposes.

What is energy intensity?

Energy intensity is annual energy use divided by floor area, expressed in kilowatt-hours per square metre per year. Lower intensity means a more efficient building. It is the core metric behind operational ratings like the Display Energy Certificate.

Why combine electricity and gas?

Operational ratings consider total delivered energy across all fuels. The tool sums electricity and gas in kWh to get total annual energy, then divides by area. For a primary-energy or carbon view you would weight each fuel, which a full assessment does.

What does the gap to next band show?

It shows how many kWh per square metre per year you would need to cut to reach the next better band. Multiplying by floor area gives the annual energy saving required, which you can translate into measures like insulation, lighting, or controls.

Does building type change the result?

Yes. Benchmarks differ by building type because a data centre, a warehouse, and an office have very different baseline energy needs. Selecting the right type applies an appropriate band scale so the rating is meaningful for that use.

Building Energy Performance Rating Estimator (EPC/DEC)

This estimator gives a fast indication of a building’s energy performance band from its actual annual consumption and floor area. It is an operational intensity screen — useful for landlords, property managers, and sustainability consultants deciding where to focus — not a substitute for a certified EPC produced by an accredited assessor.

How it works

The core metric is energy intensity: total delivered energy per unit of floor area, mapped to a band scale that depends on building type.

total energy   = electricity kWh + gas kWh
intensity      = total energy / floor area   (kWh/m²/yr)
band           = lookup(intensity, building-type band scale)
gap to next    = intensity − next-band threshold   (kWh/m²/yr)
annual saving  = gap × floor area               (kWh/yr)

Better bands have lower intensity thresholds. The gap to the next band up tells you how much energy per square metre you must remove to improve the rating.

Example and notes

A 2,000 m² office using 180,000 kWh of electricity and 120,000 kWh of gas has a total of 300,000 kWh, giving an intensity of 150 kWh/m²/yr — a mid-table band for offices. To reach the next band you would target the lower threshold for that band and multiply the difference by 2,000 m² to size the saving in kWh per year. Use the indicative improvement cost only as an order-of-magnitude prompt; real costs depend on the specific measures, building fabric, and local prices.