The world of timber frame building has changed incredibly over the past few years.

It has developed into a hi-tech business with precisely engineered components and is seeing an increasing share in the new homes market. Its advantages of fast construction and energy efficiency are widely accepted.

Playing an important role in the development and making an important contribution to a greater quality product is the computer software used by the companies manufacturing the timber components.

Joiners working from scribbled designs on rolled-up pieces of paper have become a thing of the past. Most of the timber-frame homes we see erected are designed using computer software.

Farnham-based RCS Construction Software Ltd says about 75% of the UK’s main timber frame producers have installed its Open House Timber Frame Suite. Pioneered in Norway, the system provides a flexible package for designing and building timber frame homes.

At the most advanced factories, designs are beamed direct to machines and sections produced to the nearest millimetre.

The system is an integrated set of modular programs, with each suitable for use on its own or in combination with others.

The Open House Architectural CAD is based on 2D plan input with auto 3D generation, producing elevations, perspectives and cross-sections of the house required. RCS says it helps turn the design process from an expensive overhead into a cost-effective resource.

The Timber Frame CAD is fully compatible with the Architectural CAD, so designs are converted automatically to timber frame construction.

Productivity and efficiency

It generates production information for traditional or full/partial automated production lines, with cutting lists available by panel or by total, grouping common sizes together to ensure productivity of sawing and timber sorting and most efficient use of timber.

Manufacturing details include wall panels, floor panels, gable/spandrel panel, joist layout and roof layout.

Configuration includes corner and junction details, door and window openings and beam pockets.

An estimating and scheduling program linked to the CAD system generates accurate estimates, building material schedules and also helps to control margins and ensure projects are delivered on site just in time.

IJM Timber Engineering Ltd of Monaghan, Republic of Ireland, has been using the RCS system package for the past nine years.

The company, which started up in 1965, makes in the region of 900 homes a year and has 120 employees. It runs 18 computer workstations with the RCS software, making it the largest user in the UK or Ireland.

All wall and floor sections are automated from design to manufacture, with completed floor and wall design data being sent straight to saws and panel makers. Roof trusses are made using a separate system.

Great flexibility

CAD systems manager Austin McKenna says the design software provides great flexibility. ‘Beforehand, the design was not nearly as detailed. The architectural drawings were all being done by hand. This was a lot slower, probably taking two days to do the drawings instead of one,’ he adds.

The software also gives IJM an advantage over brick and block housebuilders, Mr McKenna believes. ‘What you design is what is manufactured. We are one of the few companies who have a direct link from the CAD system to the panel makers.’

So, basically, what you see on screen is what comes out the other end.

A new feature of the software will allow IJM to show 3D house models on its website with different rendering – stone, tile and plaster – chiefly aimed at private housebuilders.

The new, improved 6.2 RCS system features multiple windows to see different views simultaneously plus rendering and animation all activated from current drawings. Whole projects can be e-mailed with one click.

Milton Keynes-based Pace Timber Systems Ltd was formed in 1999 by two ex-Prestoplan men Phil Key and Jason Pritchard.

Both had experience with the RCS system at Prestoplan. They have looked at other systems but have not been convinced to change.

Pace is using both the 5.2 and updated 6.2 system on five workstations.

Technical mana-ger David Powis, who has used the RCS package for eight years, says: ‘It takes out some of the more laborious jobs and gets the cutting lists right. Building a ground floor can be done in a morning.’

Unlike some prefabricated housebuilders, Pace runs an essentially manual production line, so the RCS software does not download information straight onto machines, but panel cutting lists are printed out and handed to workers.

Director Mr Pritchard says: ‘It’s not something we need to do at the moment but we have discussed it for the future.’

Rapid growth

The company is a good example of the sector’s rapid growth. Last year was its first year in business with a turnover of more than £2m. Extra factory space has been acquired and this year turnover is set reach around £6m. Mr Pritchard said: ‘The level of business in the market means demand is outstripping supply. That is the case for all timber frame manufacturers.’

Recent destinations for its wall and floor panels have been Sovereign Harbour, Eastbourne, and a 104-unit conversion of an old post office in Newton Street, Manchester. Its total build this year could be around 1,000 properties.

PPK Timber Frame Designs near Bristol is an independent design studio using the CAD RCS system. It is run by Paul Kemmish and Philip Payne, both of whom have a draughtsman background.

In the past they used older computer design systems but nothing that handles roof sections, joist layout and integrated sections like today. They have a wide range of clients, taking overspill from large manufacturers like Wilcon (Prestoplan) and Taylor Lane, right down to small companies without design software of their own. Bungalows, 80-bed nursing homes and five-storey flats are all designed on their screens.

‘The industry is millimetre precise, not like bricks within a couple of inches. It is an accurate engineered product,’ says Paul Kemmish.

‘Everything has moved away from the boards to the computer. Five years ago something might take us four weeks to do but now would take two weeks.’

200th licence

Earlier this year RCS reached a milestone when it sold its 200th licence for the software to Alpha Timber Frame Ltd of Godalming.

RCS business development director Nigel Willis believes the system’s success is down to its simple practical use.

He also enthuses about RCS’s recent partnership with global building components giant MiTek.

The only potential problem could be a shortage in skilled staff to operate the CAD packages as the industry continues to grow.

But what of the future for timber frame design?

Lee Dunn, CAD manager at RCS, says: ‘I believe the future for the software will depend on flexibility and the need to seamlessly interact with other design software, be it truss design, interior design and onto powerful virtual reality applications.

‘These are already beginning to materialise but the interaction between the vast choice of systems available must develop.’

Mr Dunn says new build house customers increasingly want to distinguish their homes from surrounding ones, so want specific design changes to set them apart.

‘The web will play a major part in this progression to customer input, where not only material specifications such as facing brick/roof tiles and window styles can be selected and visualised, but physical structural amendments such as internal wall positioning and bay window additions. This will enable housebuilders to deliver to the customer’s exact requirements.’