Greening the urban landscape

There is a growing recognition, both nationally and internationally, that our approach to the built environment requires a re-assessment. Increasingly green infrastructure within the urban realm will, and to a certain extent is, being seen as a major player in this realignment.

Buildings and the built environment are major sources of carbon dioxide emissions. Energy use and the impact of hard surfaces on surface water run off and the urban heat island are all issues of adaptation mechanisms to climate change in our cities. Whilst traditional responses to drainage and issues related to city wide heat waves and the energy performance of buildings have relied upon a grey infrastructure response – more pipes and more air conditioning – there is a need to move toward an ecosystem services approach. Such an approach requires embracing green roof and wall technologies.

The second World Green Roof Congress [WGRC] in London provides a unique opportunity for professionals within the built environment to witness the latest developments in this field, whether it is the development of city wide policies, the latest implementation techniques or detailed research on how green roofs and walls perform within the sustainability agenda.

These themes are as important today, a time of fiscal restraint, as they were when the first London WGRC was held in 2008. Government businesses are in possession of a large portfolio of buildings, whether it is hospitals, local authority buildings, the fire service, job centres or the MOD. Buildings are part and parcel of the public sector. Many such buildings will or are already in need of refurbishment.    
   
Understanding how green roofs and walls can be part of the refurbishment programmes will help climate proof old buildings and extend their working life. The same will apply to new developments, whether they are schools, new offices, accommodation, and so on.

The whole sustainability agenda
An ecosystem service approach to the built environment is not a singular approach, instead it takes a more rounded view of how ecological processes can meet a range of issues across the sustainability agenda. Whilst there is no doubt climate change and carbon dioxide emissions should be high on the agenda, we also need to address issues related to water, biodiversity, air quality, noise and the extended life of buildings.
   
Green roofs are often dismissed, primarily because they do not score as high on the energy and carbon dioxide emissions as some would like. Green roof technology is one of the few technologies that provide a range of benefits. This has started to be recognised at policy level throughout the world, from Portland, Oregon in the USA to Tokyo in Japan.

In the UK, London has been at the forefront of advancing the green roof agenda. The Greater London Authorities’ green roof and wall policy has been in place since March 2008. During the period of 2004 – 2008 we know that over 450,000m2 of green roofs were installed in the capital. It is likely that at the WGRC in September the latest figures will be available to demonstrate how the policy is having an effect. However below the GLA, are the 32 London boroughs, many of which have been very actively pursuing green roofs through the planning process.            

The London Borough of Islington has been spearheading this approach and they will be providing details of their approach and the reason for their success at the Congress.

Biodiversity
One of the major drivers in London and elsewhere in the UK for green roofs has been biodiversity. New guidance on green roofs and biodiversity will be presented at the Congress. This guidance will soon be published by Natural England and has been written by Gary Grant, Dr. G.Kadas one of the world’s leading researchers in this field and myself. All government businesses and local authorities need to show how they are addressing biodiversity issues within their activities.

The three premium sponsors of the WGRC are leading green roof suppliers in the UK. Their work is based on exemplar green roof systems developed in Germany and modified for the UK market. Flag-Soprema UK Ltd’s nature roof on the Tremough Campus in Cornwall (case study one) is an excellent example of a green roof that fits into the ecological context of the South West.

Bauder Ltd has a long track record of supplying green roofs on local authority buildings, such as the Ethelred Estate in the London Borough of Lambeth. At present both Bauder Ltd and Flag-Soprema UK Ltd are involved in retrofitting a number of green roofs in London on local authority offices or housing stock.

The importance of planning
Planning has an important role to play in mainstreaming green roofs in the UK. Whilst there is a need for clear codes of practice for green roofs in the UK, which will be addressed at the Congress, planning authorities have an important role in ensuring that the quality of green roof implementation is embedded in conditions. This has been the great achievement in Germany, the leading green roof market in the world. Whilst they have strong green roof codes of practice, the quality of the green roofs installed is actually down to individual cities providing clear policy and planning requirements at a local and regional level. A number of London Boroughs have relatively detailed approaches to green roofs, as do Brighton and Hove and the City of Sheffield.    

The New Providence Wharf development in the London Borough of Tower Hamlets delivered by another premium sponsor – Alumasc Exterior Building Products Ltd, is an excellent example of what a local planning authority can achieve. This was the first green roof planning condition for biodiversity in the borough and the work of the planning and landscape teams ensured that this exemplar project, achieved what was required. Today the roof is well visited and has featured on a number of television programmes.

With hotter summers and the likelihood of increased intensive summer storms predicted as a consequence of climate change, green roofs have a distinct role to help ameliorate these effects. The Congress is fortunate to have a number of recognised authorities on these issues. At the time of writing this article new evidence from the largest green roof in Washington DC, USA points to a 30 per cent decrease in energy use since the installation of a green roof on the US Postal building. Although for some this is research from beyond the UK, the data and evidence does suggest that green roofs will have an important role in reducing energy loads within buildings in cities in the UK.

Green roofs and ecosystem services are now part of the built environment agenda. However a full understanding of the range of benefits and how these benefits relate to one another needs to be understood by all involved in designing, project managing and delivering buildings within the built environment. The Congress offers the only chance to engage with a range of independent authorities from around the globe and many UK suppliers.

Dusty Gedge, president of the European Federation of Green Roof Associations, director of Livingroofs.org Ltd and lead consultant with www.greenroofconsultancy.com

Case Study: Tremough campus in Cornwall
The CUC Tremough Academic Building was a new build project with 3,000m2 of living green roof specified for the new academic building.

The green roof was chosen due to its environmental qualities, as well as for aesthetic purposes and the building was intended to blend into the landscape. A fantastic wild flower roof with locally sourced plants was erected onto the site.
 
An Optigreen nature roof from Flag UK with wild seed mix from the local areas was loosely laid onto Tremough Campus.
 
The ‘Nature roof’ (which contains Flagon TPO as its waterproofing layer) provides a high diversity of species of flora and fauna with long lasting blooming effect and is consequently of high ecological value. Discussions with local advisors and residents led to the agreement that Flag UK should incorporate a wildflower roof with native local species rather than the originally proposed sedum roof. This had the effect of reducing costs and also ensuring that the roof fitted with the surrounding area and would flourish in the maritime climate.

This environmentally friendly project saw all parties working together in a true spirit of co-operation and commitment. Both the architect, contractor and Flag UK spent a substantial amount of time planning and clarifying requirements which added to the overall success of the build.

The WGRC takes place on 15-16 September 2010 in London. For more information visit: www.worldgreenroofcongress.com