Glossary
Building performance standards and benchmarking

What is NABERS UK?

Definition

NABERS UK is a voluntary operational energy rating for UK office buildings, adapted from Australia's NABERS, that rates a year of measured energy use on a scale of 1 to 6 stars.

Who uses NABERS UK

Office landlords, developers and occupiers use it to show how a building performs in use rather than by design. Investors and tenants can compare ratings across buildings because every rating rests on metered consumption.

Rating scopes and scale

  • Scale: 1 star, the lowest, to 6 stars, market leading, based on measured energy over a year, per the Better Buildings Partnership.
  • Base building: central services the landlord controls, such as heating, cooling and ventilation plant serving office and common areas.
  • Tenancy: energy under the tenant's control, such as tenant lighting and small power.
  • Whole building: base building plus all tenancies.

Separating landlord and tenant energy

A base building rating depends on splitting landlord services from tenant loads. Aqueduct's energy balance divides facility load by feeder into HVAC, lighting, plugs and services, and Billing Management distinguishes shared from dedicated meters, showing a landlord each tenant's share of a shared meter.

Questions

NABERS UK: common questions

NABERS UK is a performance-in-use energy rating for offices, run in the UK by CIBSE under license from the Australian scheme. A licensed assessor uses twelve months of metered energy to give the base building, tenancy or whole building a star rating. It complements MEES and EPC.

An EPC estimates performance from design and fabric. NABERS UK rates the energy a building actually used over a year. A building can hold a good EPC and a weak NABERS rating if plant runs long hours or controls drift, which is why many investors now ask for both.

A full year captures seasonal heating and cooling, so the rating reflects operation in all conditions rather than one season. It also means metering gaps matter: a missing month has to be filled with acceptable evidence before the assessor can complete the rating.

Metering that separates landlord services from tenant consumption, so central plant and common areas can be rated alone. Aqueduct's sub-metered feeders and tenant sub-metering give that split, while the licensed assessor checks the meter arrangement against the rules.

See Aqueduct on your own facility.

Bring a site, a utility bill or a question. We will show you where the loss is.