NABERS UK

Does everybody need good NABERS?

The National Australian Built Environment Rating System (NABERS) has proved itself effective at significantly improving in-use energy performance in (initially mostly office) buildings in the Australian market, and is now being introduced to the UK.

There are two key elements:

Design for Performance – this is a framework providing a process, tools and advice needed to design for a specific NABERS rating

Energy for Offices – this is how the actual in-use NABERS energy rating is assessed.

Both elements are being administered in the UK by the BRE.

How are Inkling involved?

Inkling have been following NABERS with interest since Design for Performance was introduced to the UK by the Better Buildings Partnership.

Claire was in the first cohort trained to be on the UK Independent Design Review Panel this year.

Claire is also enrolled onto the NABERS UK Assessor Training course this autumn, and has recently completed the CIBSE Advanced simulation modelling for Design for Performance training course (which she discussed with Susie after each session).

Inkling have also pledged to be ‘Design for Performance Pioneer Supporters’.

Why have Inkling invested so much in this scheme?

Essentially Design for Performance is a methodology that allows us to flex all the dynamic thermal modelling expertise we have been building up through our careers, and the intent aligns closely with our mission to help make buildings more comfortable and energy efficient.

The NABERS scheme offers a protocol through which we can significantly narrow the humiliating performance gap that still dogs the construction industry. It does this by requiring a rigour and realism in the design approach akin to Passivhaus. This is backed up by detailed modelling to test the design intent including a number of ‘off axis scenarios’ which represent ways in which the building might not match the original proposals, either in terms of how the building is used and managed, or how it is constructed and commissioned.

The real genius in the scheme is that you are not assessed on the building design, the proof of the pudding only comes in operation when the actual in-use NABERS energy rating is carried out, based on the building energy meter readings. This is the point when the NABERS rating is formally bestowed. It is therefore important that the client and design team are realistic and not overly optimistic about how many stars they will achieve to avoid disappointment and embarrassment when the in-use rating comes through. A failed target may lead to financial penalties paid to tenants who were promised a building with more stars than delivered.

With that in mind there is significant pressure and responsibility on the modeller to provide an accurate representation of how the building will perform, and to do this they will need detailed information about the design including the HVAC systems and the control logic. It is important to note that this advanced simulation exercise:

Includes detailed HVAC modelling
Provides an estimated NABERS UK rating
Answers the question: “Can the project, in theory, achieve the target rating?”
Questions the design, rather than validates it
Considers ‘off-axis’ scenarios that could alter building performance

An important part of the Design for Performance process is the Independent Design Review. This review is carried out by an NABERS accredited individual (such as Claire) who reviews the building design, the ‘Rating Achievement Plan’ and the modelling report and challenges any aspects that are not well evidenced or explained and offers advice for improvements to the design. Ultimate responsibility for the star rating targeted remains with the client/design team, but the design review should help them feel more confident that what they have asserted is achievable.