8 minute read
Sustainability In Practice
Sustainability goes far beyond carbon emissions. It is about changing mindsets and behaviours. It requires an integrated and collaborative approach to design, operation and management from the entire supply chain. Collective ambition is critical, and our aim is to drive this through analysis and advocacy. Our sustainability expertsgive their opinion on the pertinent issues we face today
Net Zero Carbon
Net zero carbon is not an approach, it’s an outcome. And it’s an outcome that clients are quite rightly asking for our help to understand. But they’re doing so because they’re starting to realise that they are going to have to shoulder the burden of poor performance – both from a financial and reputational perspective. To call yourself net zero carbon you’ve got to meet embodied carbon and operational carbon targets, and be willing to pay to offset any emissions you’re left with. And you’ve got to disclose all of this publicly.
Of course there’s a cost premium associated with driving towards new performance goals. Industry data tells us that pursuing Passivhaus, for example, adds around 8% to the construction cost and similarly, we are expecting low embodied impact materials and high performance equipment to cost more. But with performance ambitions that are focussed on whole life impacts, our mindsets also need to shift from cost to value – and this means we have to lose area or adapt ways of working.
What is obvious, though, is that we can’t keep going the way we have been if we’re going to meet our local, national and global obligations. Clients, designers, contractors and occupiers alike need to take responsibility in driving change.
Measuring Green Infrastructure
As the long awaited Environment Bill mandating a minimum 10% increase in Biodiversity Net Gain (BNG) draws closer to Royal Assent, designers, ecologists and developers are navigating through the range of guidance and metrics for its measurement, alongside the other various valuation methodologies that already exist for measuring the benefits of Green Infrastructure (GI). There is currently no single tool that comprehensively enables the measurement of the range of ecosystem services GI can provide.
The Natural England Biodiversity Metric tool for BNG builds on and replaces the DEFRA metric. It focuses only on biodiversity, through a calculation of the change in units between the baseline and development proposals. Units are based on the distinctiveness, condition, strategic significance and habitat connectivity of features. What the tool reflects well, is the value of existing GI, and how established features are difficult to replace in terms of value. For example, approximately 20 young trees would need to be planted to achieve no net loss where a single mature urban tree is removed.
Even where the required biodiversity units are achieved, it is key that GI tools should be used alongside early ecological advice, to ensure that achieving certain greening targets is not to the detriment of other ecosystem services and existing site assets. It is also important to consult with the local planning authority when deciding upon the most appropriate metric for a project.
More comprehensive is the GLA’s Urban Greening Factor (UGF), a measurement that local authorities in London will be required to incorporate into policy by the New London Plan. Although surface cover factors have been developed specifically on the basis of potential for rainwater infiltration, water-holding capacity and associated soil are considered a proxy for ‘naturalness’ and ability to provide a range of benefits associated with more natural systems. Hence the UGF looks to increase functionality as well as quantity of GI. What is not clear, is the extent to which wider ecosystem service benefits such as enhanced wellbeing, community and social cohesion are incorporated.
Life Cycle Assessments
Life cycle assessment is the mechanism for assessing environmental impacts associated with all the stages of a product's life. In the case of the construction industry, we can apply this to the individual building elements to determine the total impact of procuring the asset.
We have grappled with this technique for several years with a variable degree of success but recently we have been equipped with more sophisticated tools and resources to not only quantify impact but reduce it.
The primary tool we use is One Click LCA but other tools for the construction industry exist, and individual practices are developing and publishing their own tools to fulfil their specific needs rapidly. Whilst the look and feel of these differ, the background data is sourced from the same places as they integrate many of the 30 Environmental Product Declaration (EPD) programmes and LCA databases, which are widely available. Anyone can pull this data into a database; the trick is making it useful and accessible, which requires an understanding of the overarching principles – heavy buildings consume more complex structural materials and bespoke elements consume more energy. So how can we better embed an understanding of the early principles that need to frame thinking before pen is put to paper?
We have been similarly developing our LCA strategy, in parallel with our materials specification framework, so that our design teams can undertake these, quickly and easily.
Resilience and Covid-19
In October 2016, Exercise Cygnus was carried out to test the UK’s readiness for a flu pandemic. A wargame simulated over three days, it involved 950 officials from central and local government, health services, prisons and local emergency response planners. It concluded that “the UK’s preparedness and response…is currently not sufficient to cope with the extreme demands of a severe pandemic”. Fast forward to 2021, and few would disagree.
There are clear parallels with the climate crisis that many commentators have been quick to identify. Even if every country was to achieve net zero by 2050, we will experience (and already are experiencing) consequences as the climate continues to change. The scale and pace of the response to Covid-19 needs to be leveraged into similarly speedy adaptation strategies to minimise the inevitable impacts even as we continue in our effort to limit emissions. Do our hospitals have the required cooling capacity for their patients during overcapacity and with summer temperatures rising? How safe are coastal towns and cities as sea levels rise and storms become more severe? Can infrastructure such as transport or food supply chains cope with severe disruption?
Being unprepared is not an option. If Covid-19 has taught us anything, it’s that the price of inaction is too high.
Healthy Buildings
People on average spend 90% of time indoors; this figure was reported prior to the Covid-19 pandemic when we were actively advised to stay at home.
Buildings and their complex arrangement of products have often been overlooked as regards their impact on health and productivity but ‘healthy buildings’ have more recently become a critical focal point for the built environment with a growing body of research showing that commercially available products can contain chemicals which are hazardous to human health.
Research demonstrates that in healthy office environments, productivity increases, absenteeism reduces and concentration improves. In residential environments sleeping patterns improve and respiratory issues decrease, which is vital in the current climate.
Environmental assessments such as BREEAM and WELL already consider the emissions from building products but in the Covid-19 climate, this has never been more crucial. Through better planning and informed choices, healthier building products can be specified to achieve improvements to health and the wellbeing of a building's occupants.
There are currently a number of certification schemes, which provide a measure of sustainability assurance of materials. These include: Cradle to Cradle, Healthy Product Declaration (HPDs), and the Declare Label. Ideally, only products from these and other third-party verified schemes should be specified, but they’re currently not mandatory and so can restrict the choice of materials for designers and contractors. And it is critical that ‘equal and approved’ is similarly scrutinised.
The Circular Economy
The goals of the circular economy in the built environment are to preserve natural capital and material value, optimise resource consumption through designing out negative externalities and designing in adaptability, and changing models of resource consumption.
As an industry, meeting these objectives requires holistic thinking about not only how we design buildings and select materials in their first life cycle, but how the approach to design and materials selection will affect future iterations and lifecycles.
Prioritising the refurbishment of buildings now and in the future will be critical in the shift to a circular economy. However this raises challenges; do we use highly durable technical materials that are designed for disassembly and reuse, or less durable and adaptable low carbon/bio-based materials? How do we design buildings to be as adaptable as possible for the future, but without over engineering or compromising the current needs of the building, or knowing what the future needs might be?
There is no definitive answer to delivering circular economy aims, but there is a consistent process we need to embed and follow to ensure we explore opportunities and test solutions to enable informed decision making. Utilising our work with the UKGBC and others, we need to work with our clients and wider stakeholders in developing a clear and robust brief that considers both current and future needs of our buildings, with a shift away from cost and towards value.