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Specifying water-efficient loos

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To comply with the strict water-use guidelines set out in the Code for Sustainable Homes, more and more firms are specifying low-flush WCs, says sustainability editor Hattie Hartman

The low-water target of the Code for Sustainable Homes is a powerful incentive to reduce water consumption in WCs. Flushes account for 30-40 per cent of domestic water use and up to 90 per cent in commercial premises, according to water consultancy Elemental Solutions.

Less water flushed means more for showers or baths. As recently as 2001, water regulations specified six litres as the maximum flush, down from 7.5 litres in 1993 and less than half of the 13-litre flush specified in the 1960s.

There are two types of flushes with water-efficient WCs: a low-volume single flush and a dual flush. Environment Agency research shows that an average domestic WC is used five times a day, with only one use requiring a long flush. Although market demand and public understanding of dual-flush mechanisms is growing, research by sanitary product firm Geberit showed that users in the commercial sector often press both short and long flush buttons together.

A recent DEFRA briefing note estimated that 91 per cent of WCs sold in 2008 were 6/4 litre dual-flush, and predicts that low-volume single-flush models will acquire a 55 per cent market share by 2012.

The Ifö Cera ES4, a low-volume single flush WC, combines a Swedish pan (the term for the ceramic bowl) with a British siphon flushing mechanism. Until recently, only Ifö manufactured low-flush volume WCs. Now bathroom giants Twyford and Ideal Standard have developed low-flush models, and manufacturer Impulse Bathrooms is importing a low-flush range, manufactured in China and widely used in Australia, where low-flush WCs are well-established.

The choice of designs of full systems is still limited. One approach is specifying dual- flush concealed cisterns, which are compatible with a much wider range of WCs.

That’s fine for new builds, but according to Ideal Standard, over 60 per cent of the WCs in the UK still have 7.5 to 13-litre cisterns. To seriously reduce water consumption, specifying correctly will be as important with refurbishments as with new buildings.

The AJ profiles four low-flush WCs currently on the market:

Geberit UP320 concealed cistern

Flush type 6/3 litres dual; 6 single
Mechanism Valve
Delayed action inlet valve No
Models Compatible with wall-hung sanitaryware from 16 manufacturers
Country of origin Switzerland
UK distribution Earlier models since 2001; this model from May 2008

Projects Fletcher Priest Architects, Watermark Place, London; Bere Architects, all projects
Comments ‘We use them because of their low water use, strength, reliability and ease of removal for maintenance. Also, after years of pestering them about the visual design quality of the flushing plates, they have now produced really beautiful ones.’ Justin Bere, director, Bere Architects

Ifö Cera ES4

Flush type 4.5 litre single
Mechanism Siphon, minimising leaks
Delayed action inlet valve Yes
Models available Close coupled, back-to-wall (pictured) or wall-hung
Country of origin Sweden and UK
UK distribution Since 1999 from the Green Building Store

Projects Various National Trust properties. Architype specifies Ifö on all projects, including its own offices
Comments ‘We’ve been using Ifö for years. I have one in my own home and at the office, and we’ve used them on various schools. The design is elegant and was specifically developed to save water.’ Jonathan Hines, director, Architype

Twyford Galerie Flushwise

Flush type 4/2.6 litres dual; 4.5 single
Mechanism Valve
Delayed action inlet valve No
Models available Close coupled (pictured), back-to-wall and wallhung available as 4.5 single flush
Country of origin UK
UK distribution Since 2007

Projects ECD Architects’ terraced house in Mottingham; Wolseley’s Sustainable Building Center in Leamington Spa
Comments ‘The Galerie Flushwise is installed in our Sustainable Building Center and is a key contributor to its improved water efficiency.’ Tim Pollard, head of sustainability, Wolseley

Ideal Standard/Armitage Shanks Concept

Flush type 4/2.6 litres dual; 4.5 single
Mechanism Valve
Delayed action inlet valve Yes, bottom inlet only
Models available Close coupled, back-to-wall (pictured), wall-hung
Country of origin Mostly UK
UK distribution 2008

Projects Manufacture started in 2008; none as yet
Comments ‘Finally, UK manufacturers have caught up [with European firms]. It’s great that we now have the choice not only of a 6/4 litre dual flush, but also in the lower volume, 4/2.6 litre [category].’ Cath Hassell, director, ECH2O water consultancy

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