Construction industry needs to act now to have impact on water stress in the UK

It is estimated that water harvesting can save up to 50% of mains water usage in the home and up to 80% in commercial / industrial installations.

The Government’s Code for Sustainable Homes has tried to encourage house builders to install rainwater harvesting and grey water reuse through voluntary action but the pressure is on and legislation will soon follow the voluntary initiatives and incentives.

Parts of the construction industry that fail to act now could find themselves with negative public relations, in conflict with planners and unpopular with councils and in a very short time, in breach of the law.

British Water, as the trade association representing manufacturers, design, construction and installation companies in the UK water industry, has specialist focus groups that work with regulators, industry and environmental organisations to improve standards by concentrating on elements of good water usage encouraging sustainable drainage and correct sizing and design (flows and loads) of small wastewater treatment systems.

Mike Norton is the chairman of the Sewage Treatment Plant Focus Group at British Water and of Rainwater Harvesting Association, and he believes it will take legislation before we start to see any real differences to our water consumption. He says: “Legislation will come but it may come too late. In the meantime, the water, construction and contracting industries can play a really influential role in helping this country to deal with problems now, rather than in 50 years time when we are at crisis point.”

The Code for Sustainable Homes which was introduced in 2007 set the target of reducing drinking water consumption per person per day from 150 litres to 80 litres but it has proved easier to push for these targets in the social housing sector rather than in the private as grants are only available to schemes that achieve 105 litres a day-- an incentive that has worked well in the social housing sector.

As from May 2008, the code is mandatory and measures nine categories of sustainable design including water consumption, but the code only applies to new homes, giving buyers information on the sustainability of their new home.

Although builders are still not obliged to build to its standards, consumer pressure
is mounting and by being seen to be building more sustainably, companies can differentiate themselves from the competition, giving themselves an edge in this competitive climate. Builders can also gain extra points on the homes’ sustainability ratings if 30% of water used is rainwater or grey water—a popular marketing tool that impresses prospective purchasers.

Making houses more sustainable at the point of construction has become a major issue but one of the practices that comes under criticism is the fact that we put drinking water in our toilets.

At the moment, Britain’s per capita daily use of water is 148 litres, which is one of the highest in Europe. While the revised Building Regulations Part G, which comes into operation this October, put the optimum figure at 125 litres a day, the Code for Sustainable Homes goes even further and targets 80 litres a day per person.

Norton said: “We spend a fortune purifying water that is just going to be flushed down the drain. Water harvesting can be installed so easily so that old bah or washing machine water could be used to supply toilet flushes and rainwater is collected to water plants and flowers.”

Periods of hot, dry weather exacerbate the problem as people use more water for showers, garden watering and washing clothes-- a hosepipe uses 1000 litres of fresh water an hour. With increased amounts of water being flushed down the drain, combined with the inevitable storms that follow periods of hot weather, the drains cannot cope and flooding ensues.