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Willmott Dixon in the right frame of mind

SOCIAL HOUSING

Willmott Dixon is using its long-term partnering contracts to forge ahead with innovation in its house building division.

Phil Bishop reports

GIVEN that Sir Michael Latham is the company's chairman, it is perhaps no surprise that Willmott Dixon seeks to be a pioneer in modern methods of construction. It was, after all, the 1994 Latham Report, Constructing the Team, followed by the 1998 Egan Report, Rethinking Construction, that kick-started the industry into exploring more efficient ways of working.

Willmott Dixon's housing division, which concentrates exclusively on social housing, strives to be at the leading edge of innovation, both in its procurement strategy and its construction methods. Central to this is Brendan Ritchie, innovation and sustainability director of Willmott Dixon Housing.

Asked for examples of the division's innovations, Mr Ritchie says innovation means different things to different people, but that at Willmott Dixon it is all about driving improvements in performance - reducing defects, speeding up work and getting predictability of time and cost.All of these have supply chain management implications. Supplier numbers have been reduced and partnering relationships established.

'There are efficiencies to be gained from using fewer suppliers, ' says Mr Ritchie.'We get a better service from them, because of the higher volume, and we can do product development work with them.'

A big part of the strategy is to reduce the amount of tendering the company does - the process is inherently wasteful unless every bid is won - and instead concentrate on negotiated contracts or partnering. Last year Willmott's housing division did not tender for a single job. Its entire workload, which was 10 per cent up on 2003, was partnered.This was made possible by the fact that 80 per cent of the company's work is with just 10 customers.

'That allows us to understand what they want from us and what services we give them, ' says Mr Ritchie.

Tendering has not been ruled out completely.A company planning to grow by 20 per cent a year has to find new customers, and tendering is usually the only option for this.However, the division will only tender for 'really big' projects, says Mr Ritchie.

Eliminating a substantial amount of wasteful tendering work has allowed the company to reduce staff overheads.Overheads in 2003, relative to turnover, fell 26 per cent on the previous year and turnover per person rose 36 per cent. In other words, the division is becoming a more efficient business.Through technical innovation, it is also becoming a more efficient builder.

The UK new-build social housing market is in the region of 15,000 units a year, and set to rise to 17,000 to meet needs.Willmott Dixon Housing builds about 1,200 units a year, giving it around 8 per cent of the market.

The company focuses strongly on the use of preconstructed components, first with frames, and more recently with bathrooms.

In 2004 approximately 60 per cent (by value) of the division's work used lightweight timber or steel frames rather than traditional masonry construction.This year as much as 80 per cent of the work will use frames.

The division started working with timber frames in 1999, always using timber from only sustainable sources, and in the past couple of years the use of steel has begun to take off.

Mr Ritchie says that for structures up to two or three storeys high, a timber frame is perhaps 5 per cent cheaper than a steel frame.Higher than three storeys and steel's advantages become a factor. It does not shrink or expand in the way wood does, and a structure can be achieved with every vertical perfectly plumb and every corner perfectly square.

'With increasing densities and higher rise, light steel frame is starting to get a foothold.We are starting to find it's the best technical option.'

For structures of five stories or more, Willmott Dixon housing uses a concrete frame.This is because at the moment, the division's steel frame supplier, Fusion, based in Ireland, can only supply structures up to four storeys.However, says Mr Ritchie: 'Fusion is developing their product to go higher.'

Frame construction has several benefits.The method is less dependent on traditional trades, particularly bricklayers, and so gets round the issue of skills shortages to an extent.The phasing of work is less critical too, since the roof goes up much more quickly.

There are also cost benefits in meeting building regulations concerning insulation.With traditional brickwork, larger cavities are needed for insulation material.Timber and steel frame constructions are more airtight, says Mr Ritchie.

Most significantly, lightweight frames also speed construction, as demonstrated by the company's Accelerate Programme Initiative, a yearlong project in Welwyn Garden City, completed last October.On this project, Willmott Dixon completed 94 timber framed houses in 52 weeks, which Mr Ritchie says is 30 per cent faster than it would have been with traditional methods.The element of off-site manufacture makes the system inherently faster, he says, but there are also benefits that come from the geometrical accuracy of the structure. Kitchen units, for example, fit properly first time.'There's a huge reduction in the amount of adaptation needed on site, ' he says, and in the amount of reworking and snagging.

This project also saw the use of factory-built cassette floors, with engineered joists to make it easier for routing services. Plastic pipework that can be gently curved was used to reduce section joints.

The project was also aided by spending longer on the pre-construction phase.All the design work was done and the procurement was in place before work started on site.

None of these aspects were previously untried by the division, but the Accelerated Programme Initiative was a way of bringing all aspects together on a pilot scheme with tough time targets.Had the project been built just using Willmott Dixon's standard timber frame techniques, without the additional initiatives, it would have taken 66 weeks, says Mr Ritchie.

'The process was to capture all the learning for a one-off test, ' he says.

'The job now is to use what was learned.'

Overall, the Willmott Dixon approach is cost-neutral, says Mr Ritchie.

Timber or steel frame is a more expensive method, but takes less time to build.

'I wouldn't say at the moment there's an overall cost saving on projects.

The money is just distributed differently.However, we are managing the risk of overruns better.'

Factory-assembled and ready to plumb in

AS WELL as using more light frame construction, Willmott Dixon is exploring ways to standardise. In February, for example, it announced that following its success with a few pilot projects, the company's policy was now to use bathroom pods, or factory-assembled bathrooms as the company calls them.

The use of bathroom pods is common in hotel construction, where there is the necessary volume and standardisation, but they have not been widely used in house building.The use of frame construction lends itself to bathroom pods, Mr Ritchie says: 'They are engineered products and fit well with an engineered frame.'He says he would not use them with traditional construction because the dimensions are never quite plumb and square enough for a pod to fit precisely.

The company began looking at the FAB concept after a productivity assessment it commissioned from the BRE in 1998.

The study found that on a typical construction site, when work was being carried out it was generally being done efficiently, with only about 8 per cent waste. But there were a lot of gaps when people were not working.They were just waiting until they were needed because the sequencing of events was never perfect.

'We found that bathrooms were particularly labourintensive. It was taking six months to do them and still resulted in 10 hours of snagging, ' says Mr Ritchie.

The issue with bathrooms is that so many different trades are required, with plasterers, electricians, plumbers, tilers, floor layers and so on each waiting their turn.

In 2001 Willmott Dixon Housing used factory assembled bathrooms for the first time - just four units.Another 30 were used on a scheme in 2003.Then last year it decided to use them on a much larger project, the 285-unit Burlington Danes key worker accommodation project in west London for Hammersmith Hospitals NHS Trust and Thames Valley Housing Association.At its peak, 30 bathroom pods were craned into place in just one morning.'By moving towards this gradually, it builds up our confidence and keeps customers on board, ' says Mr Ritchie.

Willmott Dixon Housing is the first affordable house builder to embrace the concept.'We have taken this quantum leap after a lot of detailed research and planning into factory assembled bathrooms.Their assembly in carefully controlled factory conditions provides improved quality, while easy on-site installation by crane speeds up timescales as they just need 'plugging in' to the main services.

'There is a perception that this is more expensive but surveyors don't cost for all the inefficiency and waste.'

Working with its two biggest customers - Circle 33 and Catalyst Group - Willmott Dixon Housing has produced six standard bathroom designs, three for houses and flats and three for sheltered accommodation and care homes.A strategic supplier for bathroom pods will be appointed imminently.

Unlike bathroom pods seen in many hotels, the company's factory assembled bathrooms are not made of glass-reinforced plastic. Instead they come in a hollow-section steel box.'They look just like they would if they were built on site, ' says Mr Ritchie.'The tenant shouldn't be able to tell that different construction methods have been used.'

Mr Ritchie and his team are now exploring possible next steps, developing standardised internal layouts, although there are transport issues to consider.A bathroom is small enough to fit on the back of a lorry, but a bigger room would require special transport. Kitchens may be the next thing to be factorybuilt, he says.'It could take two or three years before it becomes the norm, but we've already started to think about it.'