249: BREEAM, NABERS or EPC – what do these green energy ratings mean?

A commercial development at 10 Station Road in Cambridge is the first in the city to achieve a BREEAM ‘outstanding’ rating, as well as being the first NABERS rated building in the city. Funded by Aviva Investors, the building is part of Brookgate’s ongoing development around Cambridge Station and is due to be completed in 2024. Commercial buildings are increasingly being rated according to various green building rating systems, but what do these ratings actually mean for investors, developers and occupiers and what distinguishes one rating system from another?

What’s an EPC?

An Energy Performance Certificate (EPC) rates how energy efficient a building is, from grade A to G, and is legally required for a commercial property if the property is to be rented or sold or if a building under construction is finished. The purpose of an EPC is to make sure a building’s owners and its tenants have access to information about the energy efficiency of the building and so that they can identify areas for improvement.

What’s BREEAM?

BREEAM (Building Research Establishment’s Environmental Assessment Method) and NABERS (National Australian Built Environment Rating System) assessments are voluntary and assess the green credentials of a building rather differently. A BREEAM certification assesses the environmental impact and sustainability of a building. Assessors give credits across nine categories, depending on whether the building falls into the New Construction, In-Use or the Refurbishment and Fit-Out section. A percentage score is awarded; a score of 85% or more would qualify as outstanding. BREEAM is a design-based energy rating and takes into account such things as the health, safety and comfort of occupants of the building, so the interests of occupiers are very important to the rating.

What’s NABERS?

NABERS UK measures and rates the actual energy use in a building; in other words, it uses real world data rather than points being awarded by an assessor for meeting criteria. A building’s efficiency is measured in terms of energy, water, waste and the indoor environment and a star rating is awarded, from one to six. NABERS provides a benchmark for a building’s performance as compared with comparable buildings. In addition, the rating awarded is only valid for 12 months and so ensures that the rating represents a building or workplace’s current operational performance.

Which green energy rating should we use?

EPCs, BREEAM and NABERS each offer a different way in which to rate the green credentials of a commercial building. EPCs are a legal requirement and, alongside the recommendation reports that accompany them, they represent a reference point for owners and occupiers and a way in which to identify areas for improvement. EPCs are valid for 10 years and the EPC system is design-based; it provides an assessment of efficiency based on how a building should perform in theory.

A BREEAM certification is primarily based on an assessor’s scorecard and spans a wide range of criteria ranging from land use to health and wellbeing factors. It offers a holistic view of the environmental impact of a building and the comfort and wellbeing of occupants is an important factor. By contrast, NABERS is a performance-based scheme and provides an assessment of efficiency based on how a building actually performs during each 12 month period.

As society becomes increasingly aware of the need to pursue net zero carbon targets, it is not surprising that commercial buildings such as 10 Station Road in Cambridge are being promoted on the basis of excellence in more than one energy efficiency rating system. Indeed, the Government has been consulting on whether owners and tenants of buildings over 1,000 sqm will be required to obtain an annual efficiency rating for their building, such as NABERS, so a compulsory multi-level ratings system may not be far away.