Technical explainer: NABERS
The third in a series of Technical Explainers published by the NLA,
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NABERS UK-Design for Performance is a process that enables developers and owners to achieve a rating for the energy efficiency of new office buildings. Anyone planning on constructing a new office building, or undergoing a major refurbishment, should definitely consider implementing NABERS UK. Not only will it help you understand your building's performance compared to other similar buildings, but it will also provide a more accurate understanding of how much energy your office will really use in practice, making it a fantastic way to create and promote energy efficient office buildings.
NABERS UK-Design for Performance is based on rigorous energy modelling and an independent design review of all aspects that impact energy use. This makes it much more accurate than an EPC as a guide to a building’s likely energy performance. The process is based on the energy aspects of the National Australian Building Environmental Building Rating System (hence the NABERS name) which has been operating as Australia’s sustainability rating system since 1999. The UK version is managed and operated by the BRE.
In addition to NABERS UK – Design for Performance, the BRE also offer NABERS UK – Energy for Offices. This is certification based on the measured performance of a base building and can be applied to any office that is currently in use and is the process for certifying a building’s energy rating once they are fully occupied.
So, how can your building achieve the best possible score?
There are three key things to focus on:
Minimise energy use and maximise on-site generation. Some of the highest impact strategies are to simplifying the design as far as possible, making use of mixed-mode ventilation strategy and ensuring that the design has excellent fabric efficiency and sensible glazing ratios.
Carry out thorough Energy Performance Modelling of the Stage 3 design, identifying the areas that carry the highest energy-use risk and fine-tune the design to mitigate them.
Create a detailed plan for how the building will be commissioned, handed over and managed in use. Don't forget to include a tenant fit-out plan and detailed NABERS-specific Employers' Requirements to clearly tell the main contractor what they must do to mitigate key energy risks.
All the factors above were crucial in securing a 5.5 Star rating for 11 Belgrave Road, our first NABERS UK project and the first to formally target a 5.5 Star rating (the highest target rating achieved so far). There are now also two other projects that are formally targeting 5.5 Stars and I’m sure that we will soon see a project achieving the top rating of Stars.
But why go to all this effort? Well, there are plenty of good reasons! For starters, implementing Design for Performance can increase the likelihood of achieving a Net Zero Carbon development in operation. It's also a great way to attract high quality tenants who have carbon reduction targets (such as science based targets) and can even help reduce capital costs by making sure that the MEP systems aren't oversized. Plus, it can improve build quality and operational performance in addition to the marketing opportunities of excellent environmental credentials. And as an added bonus, the process includes an independent design review to highlight any risks and opportunities before construction starts.
Now, let's talk about cost. The price of implementing NABERS UK Design for Performance can vary, but you should generally budget around £30,000 - £40,000 for design for performance modelling, production of a commissioning, training, and handover plan and management of the DfP process. You'll also want to set aside around £10,000 - £12,000 for an independent design review, and at least £30,000 for handover and aftercare support. So, in total you should generally budget for at least £70,000 to £85,000 for implementing NABERS UK Design for Performance. While it may seem like a significant investment, the benefits of implementing NABERS UK are well worth it!