Whether dead or alive trees are an important resource that we at DLG aim to work with whenever possible. As architects we are an important catalyst in promoting their use in both states and can potentially make a substantial contribution to minimising global warming and the future impact of climate change.
Whilst alive they are wonderful assets to any scheme and their contribution should never be underestimated. At the outset of any project with the help of arboriculturalist’s and landscape architects we look to retain all viable trees. After all they offer so much; solar shade, cooling, capture of pollution, reduce land erosion & flooding, biodiversity, wellbeing and of course carbon sequestration. Visitors, staff students and the local community at DLG’s Ashville College in Harrogate have benefited from this approach during the recent provision of car parking. Through careful substrate specification and layout design over 100 car parking spaces have been sensitively provided within some prominent existing mature woodland.
Where poor quality trees were removed they were replaced on site several times over. It would be fabulous if we could use the green timber from felled trees within a projects on site but this is rarely practical.
However when we are using timber we aim to source it locally or if not possible from recognised certified schemes such as FSC and PEFC. The specification of timber for building structures and cladding is where architects with their clients blessing can really have an impact.
Many facets of our industry seem to be pre-programmed into using steel or concrete for building structure. It’s often what the team know and are comfortable with. In comparison to timber both materials have high embodied carbon values and this should be a good enough reason to get out of our comfort zone? Timber had many positive attributes; Natural fire resistance, easily & accurately worked, carbon sequestration, strong and flexible, aesthetically appealing. Some of these attributes were helpful in promoting the use of glue laminated timber within the exposed roof structure of DLG architects designed Marks & Spencer’s food outlet design off Leeds Rd, Harrogate. For yet further carbon sequestration and of course visual appeal we added untreated vertical larch boarding to the external materials pallet mix.
At Derby College Ilkeston a more refined aesthetic was required by our client and treated boarding was specified to minimise the maintenance regime. Budget permitting the specification could have included Thermowood or Accoya modified timber to extend its longevity.
The projects above illustrate some of the obvious uses of timber within DLG construction projects. In the coming years we would be keen to expanded its use within our projects, perhaps utilizing it as primary material for structure and enclosure in the form of cross laminated timber (CLT)(1).Of course expanded use of timber as a resource would inevitably result in a requirement to replenish existing national stocks. Current figures show we are planting in excess of 13000 hectares a year in the UK and if we begin to use more in construction this figure will need to be increased substantially. What a better way than to start by planting trees on the upland areas feeding our river systems where they will delay the release of water and prevent severe floods similar to those seen in Carlisle recently. (2) Then we will be truly working within a “win win” closed loop circular economy in synch with the environmental systems that supports and protect us.
There’s no doubt about it as an industry our increased use of trees – dead or alive will be rewarded handsomely by minimising the growing impact of climate change as well as creating a better local environment to live and work in.
Taking all of this into consideration why not give a tree this Christmas with Trees for Life (3).
Associate Director Certified Passivhaus Designer