How To Design And Build Sustainable Construction

There is much talk at the moment about ozone layers and sustainable building practices, but very little help on how to design and build sustainable construction. This is the first in a series of articles to explore the options available and hopefully start some discussion.

The most difficult challenge facing the construction industry at the moment is how to put up more buildings to satisfy the need for an ever increasing standard demanded by the clients, whilst also trying to make little impact on the environment.

Not too many years ago in the UK, and I suspect in most parts of the developed western world, everyone was happy to work in a workplace that had minimum heating and haughty windows. If it was cold, you put on a jumper. If it was really cold you worked in a coat. Now buildings are centrally heated with air conditioning and minimum standards for space and ventilation.

BACKGROUND

There are two driving forces to make buildings more “Green." One concerns greenhouse emissions and the ozone layer. The other is protecting the environment, which includes wildlife, and not causing flooding.

For many years, the standards of construction have been increasing with the intention of making life easier for the inhabitants, but with little consideration for any effect on the environment. Now people still expect those still high standards, but in order to satisfy local regulations, they also need to be environmentally friendly.

This is not a bad thing, as for too many centuries standards have been improving. At least we don’t have to dispose of our sewage in the streets anymore. The current move to be environmentally friendly is just a natural progression from what has already been done.

WHAT HAS ALREADY BEEN DONE

For various other reasons, such as to stop flooding, reducing energy demands, and making people happier and more productive, a lot has already been improved.

On new build, rainwater is no longer free to discharge at the fastest possible rate into the nearest river, and flood the next town downstream. Water is slowed down and if necessary held in ponds or storage tanks, within the site and allowed to discharge at the same rate as from if the site was a green field. It may not be obvious to the casual person in the street. But if a site was returned to a green field state there would still be a surface water runoff into small watercourses and eventually into the rivers and sea.

The buildings are already much more efficient at using less energy. Through the use of double glazed windows, use of insulation and more efficient energy sources. First of all houses got cavity walls, then the inner leaf was made of concrete blocks which are more energy efficient than brick. Then insulation was added into the cavity. Also all windows are now double glazed and made to much more exacting standards.

WHAT CAN BE DONE

The old building and infrastructure is still in need of improvement (although most of it has undergone various stages of modernization at various times). In some cases windows have been changed to double glazed, walls have had insulation added, and modern energy sources are now used. But there are acres of old terrace houses and hard paved areas where the rain water discharges directly downstream within minutes, creating with it the potential of creating a flood downstream.

Nevertheless, reusing old buildings is more energy efficient than constructing new buildings. It is not commonly recognized that the best answer may be to do nothing (in certain cases), or that to improve existing buildings may be a better answer than to demolish and rebuild.

New buildings can have more insulation added, and the rain water runoff can be slowed even more. These are not a problem. Also new techniques will need to be adopted and accepted by the general public, such as using recycled water for toilet flushing. Generating your own energy through use of windmills and solar panels attached to the homes is another possibility.

New construction methods may be developed, perhaps even a resurgence of old techniques. Evidently mud walls are a viable option. Smaller windows will automatically make buildings more energy efficient. South facing windows will absorb heat from the sun. There will also be other savings through more efficient electrical appliances which will not be noticed.

Sustainability is a broad term describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs.' (Brundtland Commission, Our Common Future, 1987).

Some broader descriptions include social and economic welfare although these can confuse the basic issue of the depletion of resources.

Sustainability in building developments is a vast and complex subject that must be considered from the very earliest stages as the potential environmental impacts are very significant (ref Technology Strategy Board).

The built environment accounts for:

• 45% of total UK carbon emissions (27% from domestic buildings and 18% from non-domestic).
• 72% of domestic emissions arise from space heating and the provision of hot water.
• 32% of landfill waste comes from the construction and demolition of buildings.
• 13% of products delivered to construction sites are sent directly to landfill without being used.

Key decisions may be picked up by an environmental impact assessment on larger projects, but even then, this can be a post-rationalization process used to justify decisions to the local planning authority, rather than a genuine decision making process.

Clients may wish therefore to appoint an independent client adviser with specialist knowledge of sustainability during the very early stages of their project (before the consultant team has been appointed) to help them address these high level decisions.

CONCLUSION

The construction industry is just one of many industries that will have to work together in order to make improvements to the world. But we are also one of the largest energy producers and what we build also has one the largest long term effects on the world. A car has a lifespan of usually no more than 15 years, but buildings often last for 100 years or more.

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