New Guidance - Concrete and BREEAM
20 Feb 2015
Concrete in Credit
Elaine Toogood explains some of the revisions in BREEAM New Construction and how the new credits for material efficiency and adaptability to climate change are an opportunity to score credits for concrete and masonry buildings.
Last year, BREEAM UK New Construction 2014 (BREEAM NC) replaced the 2011 version of the standard. Concrete continues to offer ample opportunity for achieving the very highest BREEAM scores, its versatility of uses providing opportunities for potential points in most of the categories. Most obviously there are credits available based on the material specification and selection itself, such as responsibly sourced concrete or its Green Guide rating, but also through the performance of material in use. Concrete offers opportunity to score credits for resilience and durability and through the use of its thermal mass.
There seems to be a general consensus that, while there are many differences between BREEAM NC 2014 and the 2011 edition, the changes are not as fundamental as those experienced in previous versions. One significant shift is towards the availability of more credits early in the design process, rewarding early appointment of a BREEAM assessor and Sustainability Champion and for embedding processes from early on in the development process. Projects aiming for high scores are likely to find it more difficult to achieve if these early ‘wins’ are not bagged from the outset
A new aspect of BREEAM NC is the potential separation of assessment into stages, whereby the building can be assessed as ‘shell-and-core’ or ‘shell’ only with subsequent ‘fit-out’ stages assessed separately under the BREEAM Refurbishment/Fit out. This staged assessment process, together with the new BREEAM Refurbishment and Fit-out scheme, offers different routes through which a development can achieve a fully fitted assessed certificate, and therefore allows a means of standardised benchmarking and potentially simpler assessment of shell-only and shell-and-core developments.
The use of a concrete structure – exposed internally to use its thermal mass as part of a low-energy servicing strategy – continues to attract substantial numbers of credits in many areas of BREEAM, not only in the Energy section. This includes newly introduced credits for ‘material efficiency’ and ‘adaptability to climate change’, in the Waste (Wst) and Materials (Mat) sections respectively, potentially rewarding the natural resilience and all-round performance of exposed concrete.
In the latest version of BREEAM NC, the minimum percentage levels of recycled or secondary aggregate required to earn the “recycled aggregates” credit in Wst 02 have been lowered to 15% in the structural frame and 20% in the foundations, compared to 25% under BREEAM 2011. This is technically more achievable with current British standards for concrete specification, but will remain aspirational for many projects as there is an additional requirement to exceed a 25% replacement overall.
But not all the changes are welcomed and the current revisions treatment of responsible sourcing credits is disappointing. In Mat 03, up to four credits are available for specifying and procuring responsibly sourced materials. Under BREEAM 2011 materials rated ‘very good’ and ‘excellent’ under the BRE’s own responsible sourcing scheme BES6001 attracted a score of 3 and 3.5 respectively, with 3.5 representing the highest score of any recognised scheme. Curiously, under BREEAM NC 2014, most of the recognised schemes have been given exactly the same score, irrespective of their rating. This revision potentially undermines the effectiveness and credibility of both BREEAM and BES 6001 and BRE Global has advised that this is only an interim position. There is undoubtedly a sustainability benefit in sourcing materials accredited to BES 6001, and the concrete industry currently reports that 91% of concrete produced in the UK is responsibly sourced, with 85% of this rated “very good” or “excellent” under BES 6001.
In the latest guidance from The Concrete Centre on Concrete and BREEAM, to be launched at Ecobuild, it is shown that many issues are linked. For example, a low-energy servicing strategy using natural ventilation and the thermal mass of concrete with night-time cooling, can score significant specific points in Energy, Health and Wellbeing and Pollution categories and also potentially Waste through the section Adaption to Climate Change. This strategy also has the potential for additional scores for other performance benefits such as inherent acoustic insulation, fire insulation, durability, low maintenance and VOC-free finishes in categories Pollution, Materials, Waste and Health and Wellbeing.
This interconnection of credits includes further potential places for scores when one takes in to account performance of materials in construction and benefits such as low-waste construction, ease of recycling, locally available, off-site construction and cost-effectiveness.
Similarly the selection of a SUDs system has the potential to score points in the Water, Pollution, Land Use and Ecology categories and is assessed for further points in Materials and Waste – the score depending upon the exact material specification or selection.
To find out more about scoring credits with Concrete in BREEAM New Construction 2014: