Buildings are increasingly expected to be designed, built and operated in a way that minimises their impact on the environment. But few designers have the resources to research the environmental impact of each material used in a building – I think I would get funny looks from my peers if I started asking about the environmental impact of the carpets on a project.
This is where Envest comes in. Developed by the BRE, this software program considers the materials used during construction and the resources consumed over a building’s life to give designers an instant environmental assessment. The system covers impact on climate change and ozone depletion, production of pollutants (including carbon dioxide, sulpher dioxide and nitrogen oxide) and waste, water consumption, fossil fuel depletion and toxicity.
The program, which costs £2000, has been developed for use from the very earliest stage of a building’s design, while its form and orientation are still being considered. It will allow designers to identify instantly those aspects of a building that have the greatest influence on its overall environmental performance, such as the carpets or the roof cladding. A designer will be able to consider if the building’s layout can be adapted to reduce the roof area or whether the environmental impact can more easily be mitigated by changing the roof cladding’s specification.
This is an improvement on the current situation, where environmental consultants do not join the project until the preliminary design has been established and can only tweak what is already there. Considering the environmental impact at the outset of the design process will also heighten awareness of the subject within the design team.
To calculate a building’s eco-performance, the program asks the user to:
- Select one of eight generic building shapes or create an original building form.
- Use pull-down menu choices to input the basic dimensions and details, such as building height, number of stories, wall specification and so on. There is no need to look up U-values – the program calculates them automatically.
- Refine the design by experimenting with different specifications to see how this affects the building’s environmental rating.
- Add details of the building services – for example, how the office will be heated and lit – so that the software can estimate the office’s operational impact.
This simple four-stage system is the key to Envest’s success. To go through a series of options, ranging from type of primary structure to flush volume of the toilets, is a very straightforward way of obtaining key facts and of increasing awareness of environmental issues.
The only weakness of the four-stage set-up is that the type of construction and the materials used are all selected from pull-down menus. When all you have are options to pick from, you will always want one that is not on the list. For instance, in the test session, a trombe wall was not an option.
After the four stages, the building is given an “ecopoint”, or whole-life environmental impact, rating. The user can then compare the building’s environmental score with benchmarks for typical green buildings. It also breaks down the rating into different elements so that the user can compare different designs and specifications.
As a guide, 100 ecopoints are equivalent to the environmental impact caused by one UK citizen in one year.
Being able to equate the ecopoint to something outside the program would be very useful – for example, how many kilowatts are going to be used in lighting and how many in heating. In a large practice, there is always a specialist who can help. However, small practices cannot tap into this knowledge base, so the program could be really useful in getting quick and simple answers.
Although the software is intended primarily to enable the environmental impacts of construction and operation to be balanced over the life of a building, the operational values and environmental awareness the software generates could also prove useful as a design tool, particularly given the likely introduction of a carbon tax in the near future. Envest is also well placed to address client demands for running costs. I see it being able to tell you how this legislation will financially affect the landlord that takes the building.
Envest will be even more useful when it can be applied to other parts of the world. As I work in a practice that has many projects outside the UK, I can see myself becoming frustrated at not having this tool at my disposal.