Drainage & Wastewater
The new Design Museum, and adjacent Holland Green apartments, is a new mixed-use development at the south end of Holland Park in west London
Project: Design Museum Location: West London Architects: OMA and Allies & Morrison Drainage specialist: Geberit
The Design Museum is now housed in what’s left of the Commonwealth Institute, a distinctive Grade II Listed Modernist building which had stood vacant for over a decade. Transformed by architect firms OMA and Allies and Morrison, it has been upgraded to meet the demands of the 21st century, whilst retaining its unique spatial quality, including the regeneration of its original pavilion and the eyecatching parabolic copper roof.
Siphoning rainwater
DRAINAGE WITHOUT COMPROMISING DESIGN How does roof drainage with a negative pressure result in a positive outlook for installers working on challenging building designs in notoriously wet climates? Jonathan Briafield, Senior Product Manager at Geberit, takes a look at the advantages of siphonic systems. to Met A ccording Office figures, the UK experiences an average of 133 days of rain or snow, totalling 885mm (33.7"), a year. In fact, record-heavy rainfalls are now being experienced across the world, and this, coupled with new demands in the architecture of buildings, has seen a move away from traditional gravity drainage.
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As the roof needs to protect the rest of a building’s structure from the elements, installing an adequate and effective drainage system is an important consideration of any building project, particularly for largescale projects and for those buildings with flat roofs. For the architect, flexibility is a key issue in terms of roofing and
there aren’t any more flexible yet effective roof drainage systems available than the siphonic method.
Listed buildings The new Design Museum, and adjacent Holland Green apartments, is a new mixed-use development at the south end of Holland Park in west London.
Geberit Pluvia was specified for the roof drainage for this demanding project. Originally developed in Scandinavia 50 years ago, siphonic roof drainage systems have been in use in the UK since the early 1980s. Since then, many large projects, such as the London Design Museum, have used the siphonic system to overcome installation problems which would have been difficult to solve using a traditional gravity rainwater system. While conventional systems simply allow rain to run off the roof through sloping pipes, the compact Geberit Pluvia pipe system fills up quickly and draws the rainwater from the roof using the resultant negative pressure. The roof outlets prevent air from being sucked in and guarantee reliable performance, resulting in double the amount of rainwater discharge at half the pipe diameter. There is also greater design freedom in terms of planning, as there is no longer any need for sloping pipelines; instead, pipelines are laid completely horizontal, so the drainage system does not result in any loss of space or height. A siphonic drainage system is not only cheaper to construct than a typical roof drainage system – especially when a large industrial roof or complex roof structure has to be covered – but the system’s design means there is no need for the pipe pitch or gradients found in typical roof drain piping, making installation a relatively simple process, even