The Back Story
The History of the Carbon Challenge is linked directly to the earlier ambitious English Partnership projects, the Millennium Communities and Design for Manufacture. Both of these programmes aimed to widen the scope of ambition in UK house building and raise its standards to be comparable to our European counterparts. With the Carbon Challenge and the Code for Sustainable Homes, it can rightly be said that we in the UK are leading the field in developing the standards of housing. The Millennium Communities projects focussed on what aspects of a housing project are most important for creating a community, the Design for manufacture focussed on how to procure projects using manufactured solutions within cost targets, and the Carbon Challenge focuses on the Carbon footprint of new housing whilst also bringing together the lessons learned from the earlier programmes.
Sustainability that Sells
Our intention was to design a development that holds appeal to the broadest range of potential purchasers in the community. Commercial success should not be antipathetic to sustainability. We take the view that it is time for sustainable design to enter the mainstream of housing design in the UK, as it is already doing in other industries. The fact that Barratt, one of the largest house builders in the UK is our client is proof that this is an industry wide ambition, and no longer a niche interest.We wanted to create a design that focuses on creating places that people will want to live in, and buy into. There are several strands of thinking that have led to the design we have developed. These are:
- High quality design.
We have designed a distinctive place which uses the advantages of this green and attractive site to accentuate the benefits of living on the edge of a city. The houses are oriented to maximise the benefits of light and views and have large open plan living spaces where people can relax and enjoy both the home they have bought, and the rich visual landscape that is part of this development. Every home has a private garden or balcony, and all homes front onto a public open space, either a landscaped courtyard or part of the parkland that surrounds the project.
The amount of green open space is high and we have used it to create a varied environment with many enjoyable landscape features. Some of these are practical such as the sustainable urban drainage, some are playful, such as the play sculptures, and some are didactic. We have placed an orchard, greenhouses and allotments close to the development to encourage residents to eat what they grow, and to help them understand the benefits of local food production.
- Collective behaviour.
We believe that collective behaviour is central to designing successful sustainable places. For example we have used a centralised energy system that allows the homes to share heat and power on a site wide network, rather than give every home its own individual system. We have extended this philosophy to the design of all the services for the development, for example the parking spaces are on street or in small shared courts, this saves on the amount of space given over to parking, and it improves the public realm by reducing the number of visible cars. In some areas we have created small shared gardens where residents and their children can interact in a car free environment. In the services design we are introducing shared rainwater tanks for rainwater harvesting, and rather than spoil the streetscape with a litter of bins, we have chosen to put large bins into enclosures that are shared by groups of dwellings. This makes refuse collection and recycling easier for everyone. This sharing of services also introduces the notion that people will be more likely to meet their neighbours than would happen in other developments. There are opportunities to meet on the way to the car, to the binstore, to the gardens and in the park. All of this helps to generate a better more closely linked community.
Elements of the Design
A new Housing Template
This development creates a template for new housing development in the UK. By demonstrating how zero carbon design can be achieved it has already had an impact on the development of the new definition of zero carbon announced by DCLG in late 2008. We have demonstrated that zero carbon design can be achieved and still produce an exemplary design that meets and in some cases exceeds the highest standards set for housing in the UK.
The elements of this template are:
- Urban Structure
We have used a route through the site to organise the main frontage of the dwellings, and behind this and leading from it are a series of short streets and mews courts that are reminiscent of historic street types behind more formal main streets.
We are fortunate to have a Grade 2* listed structure on site, and we have been able to demonstrate how to integrate such a building into a sustainable development. We have done this by respecting the historical importance of the structure, but not allowed it to define how the housing is treated in visual or material terms.
The refurbished Hanham Hall will be brought back to life as a working commercial building. It will be fitted out as office space for rent, and there is already a list of prospective tenants, including a local crèche.
The primacy of the Hall as the main architectural feature on the site has been retained in the way it has been allowed to dominate the Southern vista from the site through the neighbouring development. This connection which is both visual and physical successfully ties the building into its context.
The concept of zero carbon relates almost entirely to the carbon footprint of the home itself. A proportion of it also relates to the behaviour of the occupants in their energy use of appliances. These together make up about 60% of an individual’s average carbon footprint. In designing this development we also wanted to consider how the remaining 40% might be reduced, particularly in relation to the use of cars and the transport of food. We are taking care to ensure that car ownership is reduced by limiting the availability of parking, and providing parking spaces for car clubs. We are linking into a local cycling network to ensure that residents can cycle to work. We will provide residents with information about local public transport which goes past the site.
Sustainable places must incorporate high quality management of the public realm, and this is particularly important where much of that realm is landscape and requires regular and careful maintenance. The landscape performs many functions in this scheme, providing amenity, play, security, view and opportunities for food growing and recreational gardening. It is vital that there is careful site management of this infrastructure that the residents feel able to engage with and participate in. This is part of the role of the Community Interest Company that will be set up to manage the Hall and the open space in the development. The Community Interest Trust will also be responsible for the Energy Company who will run the Energy Centre, and for the management company running the rental space in the Hall.
- Technical Standards
This development meets the highest standards currently being applied to housing in the UK. To achieve this we are using systems and products from some of the largest and most familiar names in the UK construction industry. Some examples are: Corus are supplying the roofing material, Kingspan the main building fabric and Jeld-Wen the windows. In all cases these companies have invested considerable amounts of time and expertise to ensure that they have products suitable for the Uk market which meet the exacting technical standards that this development requires. They have done so because they realise that the UK housing market is changing to an arena of very high building performance.
Meeting Code for Sustainable Homes Level 6 has meant that we are fulfilling most of the Code requirements, and in many cases we are only omitting those areas of the Code that are impossible to achieve on his particular site for one reason or another.
The homes also meet a CIBSE overheating standard, to demonstrate that UK housing must not only be low energy but must also be prepared for the almost inevitable rises in temperature that we will face in the future.
The design of this project has been a huge challenge, but it has also been a rewarding experience. Everyone who has participated has learned something, and everyone understands that this is a special project. It has been an interesting journey from inception to this stage, and when planning permission is granted the next stage of technical development will begin. We have learned, among other things, that it is very important to bring others in the industry along with us as the design develops. It is important that this project is understood by the industry as a precursor of things to come.
See http://www.hanhamhall.co.uk for more information.
See HTA’s website for more information on my employer and the lead consultant on the project
This article first appeared in a shortened version in Builder and Engineer March 2009.