Development of brownfield sites: what you need to know
Since 2008 the number of new households in the UK has continued to exceed the number of new homes built, giving rise to the current shortage in housing supply, and creating the urgent need for a period of sustained development within new house building.
The Government has set two clear targets in relation to house building supply; to deliver 1 million new homes by 2020, and to provide 240,000 homes in 2016.
In the need to identify suitable land, the safe development of housing on brownfield sites will be fundamental in achieving the objectives set by government. A. Proctor Group Ltd has over twenty years’ experience in providing solutions for the safe development of brownfield land, and has extended its range of ground gas protection products to include Protech VOC Flex, a new and innovative solution in membrane technology, specifically to make the development of these sites safer and easier.
The Government has ambitions that it expects to see local development orders being used to get planning permissions on at least 90% on suitable brownfield sites by 2020. In order to do this, it has implemented a package of support that local authorities can use, with a total of £400 million of government funding being invested to create housing zones on brownfield land.
Aubrey Machin, Ground Protection National Technical Sales for the Group explains, “The Government is referring to the use of brownfield sites that are suitable for development, not sites which are too heavily contaminated and in need of expensive remediation. The sites that are to be identified are those which developers would consider viable, with either no special environmental protection measures or sites which would be considered viable within the guidance outlined in BS8485 2015 (Code of practice for the design of protective measures for methane and carbon dioxide ground gases for new buildings) and NHBC Guidance for the Safe Development of Housing on Land Affected by Contamination” & CIRIA C716 Remediating and mitigating risks from VOC Vapours & CIRIA C748 Guidance on the use of plastic membranes as VOC vapour barriers.
The latest in ground gas protection
“However, with the emphasis that is being placed on brownfield development, more is required from the systems that have traditionally been used for ground gas protection. We therefore decided to develop a new membrane that is designed specifically to meet the needs of these sites. Principally our new membrane was designed as a Hydrocarbon and VOC membrane as in our experience, these are typical of the type of contaminates present on many brownfield developments. It is more than just another membrane offering. We have a programme of continual testing, which we are carrying out in order to provide not simply a hydrocarbon membrane, but a chemical barrier, which should be suitable against a whole range of contaminates.”
The reasons for developing Protech VOC Flex, and the benefits it provides are extensive. Previously the membranes which, were recommended to provide protection for buildings, were derived from landfill and industrial solutions, typically HDPEs of various thickness. “The main problem with these membranes is that they are incredibly difficult to work with and detail, particularly on housing schemes, where the house plots are small. So the main design objective was to produce a membrane which is highly resistant to Hydrocarbon and chemical attack, plus strong and robust enough to survive the build process (highlighted in BS8485 2015), more importantly flexible enough to detail and install quickly and easily. Our initial projections are that it should be four times faster to install against traditional HDPEs,” says Machin.
A. Proctor Group is working with developers and contractors to guide them on all aspects of designing gas protection systems. From recommending the ideal level of protection for a particular site, through to selection of suitable materials, and advice on detailing, highly trained specialists provide technical assistance to give developers the confidence to build on brownfield sites.