A group of children rushing round the opening of the 'Hardcore' exhibition at the RIBA had more familiarity with the subject of the show - concrete - than most. They were the children of American architect, entrepreneur and product designer David Hertz, whose interest in the material extends to his own home in Venice, California.
Not only are the walls and floors of concrete but so is the furniture, which was cast as an integral part of the floors. Some may consider this a harsh environment for a family home, but Hertz sees it as ideal. 'The kids can come in off the beach and skateboard, ' he explains. And there is no worry about any sand they might bring in.
'The whole house has a slope, ' he says. 'We can hose it out.'
Sadly, his own house is not featured in the exhibition, but another one he designed is. Prosaically called the 'Tilt-Up Slab House', and also in Venice, it applies to houses a technique popular for industrial buildings in the US. Concrete slabs are cast on the ground and then tilted into position by crane, greatly reducing the need for formwork and on-site skills. 'This is the first contemporary house I am aware of in the US to use that finish and leave it exposed, ' he says. Concrete is exposed on both the inside and the outside of the house (burnished internally).
So what about the insulation? Hertz claims to have major environmental concerns, and indeed one of his arguments is that using concrete avoids the consumption of trees that timber construction involves. But this is California, not Camden Town, and he relies on the thermal mass of his 17cm-thick concrete to modulate the temperature - plus solarpowered underfloor heating. The house, he says 'has a property like a cave', maintaining a near-constant temperature, and the owners found they needed no heating at all for eight months of the year.
In his architecture, Hertz includes Frank Lloyd Wright, John Lautner and Frank Gehry among his influences - he worked for the latter two during his training. But his main claim to fame is not the houses he has designed, but a material he developed, called Syndecrete.
There are panels of Syndecrete at 'Hardcore'. The aggregate seen in the surfaces varies from little black worms in one panel to luminous red and green, like inclusions of fruit jellies, in another. These are all recycled materials - and recycling is at the heart of Syndecrete and a key part of Hertz's environmental agenda.
I cannot tell you exactly how Syndecrete is made since, although the name is a registered trademark, Hertz has chosen not to patent the process. Instead he maintains the manufacture as 'a proprietary process' - that is, he keeps it a secret. But the end result, and some of the content, is known.
Syndecrete has about half the weight of normal concrete and has a much higher compressive strength. These results are achieved by the inclusion of a high proportion of fibre as reinforcement. The fibre comes from old carpets and the only stipulation is that the material must be synthetic, since highly alkaline cement would attack natural materials.
In addition, there are the recycled materials that Hertz uses as aggregates, which can be anything from vinyl records, to the rubber from car tyres, to bottle glass.
When providing material for the interior of fashion store Patagonia in Tokyo, Hertz incorporated discarded buttons, zips and fastenings. And he can add colour to his material, giving him a range of about 600 finishes.
In the applications found for Syndecrete - as tiles, furniture, surfaces or counter-tops - there is no need for steel reinforcement which would add weight and which Hertz describes as 'like a cancer inside concrete'.
The material is mostly specified by architects, which means that, instead of offering a standard product, Hertz's company, Syndesis, tailors it to a specific need.
Another recent development has been with flooring giant Interface. One of the world's largest manufacturers of carpets, Interface has embraced an environmental agenda wholeheartedly, aiming to have a production and recycling process that has no environmental impact whatsoever. For example, when any of its executives travel by air, they pay for the planting of an area of woodland that will absorb the amount of carbon dioxide generated by the flight.
One of Interface's latest projects is the creation of a raised access floor with an integral surface finish. Using his Syndecrete process, Hertz has come up with a surface that has a translucent stained finish, with exposed aggregate.
Not only does it use material from Interface's own waste stream, it also cuts the weight of the product by about 30 per cent.
'They had been shipping trucks that were half full, ' said Hertz. 'Now they can fill them with this product.'
It is difficult to tell whether Hertz' genuine concern for the environment and enthusiasm for concrete are logical consequences, or if there is some postjustification in his arguments for the green credentials of his favourite material. But his passion and imagination are not in doubt.
Syndesis now employs about 15 people - seven architects and the rest in manufacture.
Hertz is very much grounded in California - he was born in Los Angeles, studied architecture at Southern California Institute of Architecture (SCI-ARC) and now teaches ecology and architecture at UCLA.
How well his ideas could translate to the UK is questionable given that the climate, both physical and mental, is very different.
And although Hertz flew over for the opening of the 'Hardcore' show, it was for a holiday and to catch up with friends, not as a business trip.
But his approach, his questing nature and eagerness to embrace both the creation of buildings and the design and making of products, would definitely be welcome.
To learn more about David Hertz and his work, go to www. syndesisinc. com