A residential development by the Thames west of London is a major step up for the growing firm of Countywood, writes Adrian Greeman
COUNTYWOOD managing director David Briault says he has learned more in the past two years on the Whittett's Ait project than he had over his previous 20 in the industry.
Though a small project, the three-phase housing scheme involves a range of work: from demolition and contaminated ground treatment, to building and reconstruction.Along the way there is river bank engineering, flood control, bridge strengthening and landscaping.
'It's a big enough scheme for us, 'Mr Briault says.At a total so far of £7.5 million, its overall cost easily tops the £4.5 million annual turnover of the relatively new south-eastern construction firm, which he founded in 2000 along with two partners.
'That cost is spread over a few years, though, ' he also points out.
Ait, sometimes spelt Eyot, is an old Anglo-Saxon word for small island, and the scheme, for developer Latchmere Homes, involves the renovation and development of one near to Weybridge in Surrey on the Thames.To be more exact, the island sits on the Wey Navigation, formerly the river Wey, at the point where it joins the main Thames flow.This makes for a picturesque location, which will undoubtedly be a selling point for the apartments being built in the first two phases of the project. But it also creates its fair share of problems. First of these was an old steel road bridge, the sole access onto the island from the town.
'This had a load-bearing capacity of just 7.5 tonnes, ' says Mr Briault, 'and we needed something much closer to 40 tonnes if we were to get any half-way decent plant onto the island.'
The first idea was to lift out the old structure and put in a newer superstructure with a large crane. But the bridge itself was the obstacle to that - the only position the crane could operate from was on the island and of course it could not get there.
'We thought about a long lift from the landside but it would have meant a hairy reach across some local houses, ' says Mr Briault.A rethink was in order.
The answer, worked out with engineering consultant Aspen Lewis, was a strengthening of the bridge's deck.
'We hung a scaffold underneath and then beefed up the side beams and put in new cross-members, ' says Mr Briault.
With plant able to move on site, the first task was to demolish an old mill at the far end of the island. Somewhat surprisingly for a an area that is part of the Home Counties stockbroker belt, the Ait had an industrial history focused largely around a linseed oil plant and some workshops at the far end, where it sat by the canal and a small wharf.
Before demolition the details of the mill had to be carefully noted.
Countywood's design/build contract requires maintaining the outline of the mill for the new apartments, although the original structure is rebuilt.
Care had to be taken with a nearby lock keeper's cottage, which is not part of the site but has a National Trust preservation order on it.Novated architect Knight Norman Partners, which did the client's original outline scheme, took care of the details.
'We also had to treat the ground, ' says Mr Briault.Years of production for cricket bats and oil paint and some later use of the site for chemical recovery had left their toll in spilt materials.
'We had to remove hundreds of tonnes of the ground and replace it with clean fill, ' he says.Monitoring and checking had to be agreed with the local authority and removed spoil needed an approved disposal site, which does not come cheap.
Twelve apartments have been created in the new 'mill' and another building alongside. Some in this first £2.2 million phase are already let, while the contractor gets on with a second, larger £5.25 million phase nearby.
'The first section was complex enough, ' says Mr Briault, 'especially as the old mill had a complicated roof shape and an old barge loading gantry had to be reinstated, though it has become a balcony for one of the top apartments.'
The foundations are just being finished on the second stage for two apartment blocks, which will create a further 32 apartments. Planning requirements demand that eight of these be 'affordable' units be sold to a housing association.
Design here is straightforward, although the buildings have pile foundations and ground beams, partly because of flood considerations.The buildings have to sit fairly high to guarantee year-round access.
The problems are more organisational, says Mr Briault.The road from the bridge has to be kept accessible at all times for the incoming residents on the first phase, for the lock keeper and for residents of a second smaller island, which is accessed only via the Ait.
'It is sometimes a bit of a logistical nightmare, ' he says.
For that reason he is bringing in a tower crane from Select crane hire for the superstructure work this summer. It means the traditional long-reach fork lift can be avoided for moving loads.
'It would be running up and down, blocking the road all day, ' says Mr Briault.He already has four excavators to move around, two 13-tonne and two 5-tonne units and a number of small dump trucks.These are working on the road and landscaping.
They have also been used for some sheet piling work along the Navigation, where the bank was weak. Concrete block gabions will be placed behind these to shore up the waterway.
Mr Briault says that he hopes good progress can be maintained to get the roofs in place by autumn, before winter weather becomes a problem for the fitting-out.
The workforce, currently around a dozen, will rise to about 50 as the internal trades arrive.The firm tries to use the same subcontractors all the time, establishing a long term relationship where possible.
'The only condition is that they must grow their capacity along with us so that they can cope with the work, 'Mr Briault says.
It helps that the client is a good payer, as there are no delays in funding all the subcontracts and that, he says, 'transforms the atmosphere on a site' While that is going on there is landscaping to do.The centre of the island has to be public open space, a path across must be relocated and the ground level changed. Lowering the ground is partly a flood measure. It means that the parkland will take the water first and reach houses only in extremes.
A complication for the park work is that a major pipeline runs across the island carrying high-pressure aviation fuel to Heathrow airport.Very strict conditions apply to work done near or around it.'Serco flies a helicopter over at least once a week to check, ' he says, 'and they can land and stop work if they see problems.'
Even so the work is going well and Mr Briault says he is enjoying, although he admits it is 'seriously hard' He is awaiting a decision now on a final third phase of the scheme at the other end of the island.This has been held up because Latchmere wants to build residential properties rather than the offices it has planning consent for - among other things there is an Environment Agency requirement to satisfy stipulating that the properties would be flood-free.
'We hope the last phase will get going just as the second phase is finishing, ' he says.