In with the old

The exterior of refurbished Unilever House in Blackfriars, London, looks much the same as it did when it opened for business in 1932. But wander inside and it’s very much a case of ‘all change’. Gloomy offices and monotonous corridors are out; a futuristic atrium with glass lifts and suspended floors is in.

More observant visitors will also notice that along with reclaimed stone fireplaces, bronze handrails and timber panels, some of the original parquet flooring has been retained and used in the new interior.

‘Unilever wanted their building to be a link between old and new and the planners were keen to see existing materials re-used too, so it was a combination of both those desires,’ explains Scott Evans, shell and core fit-out project manager at Bovis Lend Lease.

Evans joined the project in late 2004 during the initial stripping out phase. Everything retained for re-use was catalogued and stored, including more than 5,000m2 of parquet flooring. But lifting the 70-year-old parquet blocks was tricky. ‘The timber had been bonded straight on to the slab in pattern using bitumen,’ says Evans. ‘There was no quick and easy way of removing it.’

Some of the blocks were badly worn, some were chipped, he adds, while all were difficult to remove. ‘It was a real challenge for trade contractor Swift Horseman to keep the timber in one piece when separating it from the slab so by the end of the process only about half of all the parquet flooring was salvaged.’ The pickings were then put on pallets, sealed and stored.

Victorian Woodworks undertook the refurbishment of the blocks. It kiln-dried them, removed as much of the bitumen as possible and formed new tongue-and-groove connections. Then they were machined to form standard blocks of 300mm x 60mm. ‘Because they’d been worn to different degrees they were also sanded as well to create a uniform thickness,’ says Evans.

If that sounds like a self-defeating exercise considering the amount of energy expended in rejuvenating the parquet blocks, Evans suggests it’s a case of finding a balance. ‘At first glance it’s better than using new timber; there’s no cutting down of trees or transportation from overseas whereas there is a lot of energy used in recalibrating existing materials.’

But there was another factor to consider. He continues: ‘Bear in mind this is a very high-quality, rare hardwood – Indonesian Keruing – which is unavailable today. You’ll need to wait 160 years for the next crop to mature.’

With Unilever and the architect Kohn Pederson Fox, Bovis Lend Lease decided to install the parquet blocks in a few key locations: on the suspended atrium link bridges at the eighth level – known as ‘flying carpets’ (see CM May 2006); in the lifts; on Juliet balconies on levels three and four; in the chairman’s dining area and in the ground floor conference area. In total, around 500m2 has been re-used.

Stonewood Flooring carried out the installation at the start of 2006. In the lifts and on the flying carpets the parquet blocks have been bonded to a plywood backing on battens, while elsewhere the blocks have been bonded to raised access floors. A cork trim was designed in for movement. For the lift, prefabricated panels were created to ease installation, but the blocks were mostly laid one by one.

The building re-opened in July and Evans says that unlike the new high-tech, high-spec interior which characterises the rest of the interior, the parquet flooring shows marks and imperfections. ‘But that’s the whole point,’ he adds. ‘That’s part of the character of parquet flooring and it provides the contrast Unilever was looking for.’

And no doubt the client is hoping they’ve another 70 years of life left in them. cm