Green timber construction

Green timber building using undried, unseasoned timber has become more popular in the last 20 years, thanks, according to Cholsey-based Norman Guiver, chairman of the Carpenters’ Fellowship, to the publication in the early 1980s of a book which he describes as ‘the Bible’ of the joinery trade.

Building historian Cecil A Hewitt, author of English Historic Carpentry, studied the joinery of buildings dating back to the 12th century, such as churches, masonic halls, and so on, and offered a guide to how it was accomplished.

Mr Guiver said: “That was the starting-point of a resurgence in timber-framing. Since then, these skills are being taken on board and re-learned, as to how particular types of joints were worked.”

Timber-framed structures offer a number of benefits. These range from the supplier of the timber to the builder, who can achieve cost-savings in the time taken to complete a project, and for the occupier who has a more predictable moving-in date.

A timber-framed structure can be finished well ahead of one built by ‘normal’ construction methods. One contractor can be laying the foundations, while the timber frame is being prepared elsewhere.

“The ground-worker is a specialist and that is his job done,” said Mr Guiver.

“For a project-manager, this makes progress very easy, for there are clear points of time within the schedule when you are dealing with specialists.”

In 2002, he was project-director for the new timber-framed boathouse at Abingdon School, and for the visitor centre and offices at the Northmoor Trust, Little Wittenham, in 2005.

The boathouse provides a good illustration of how successfully a project can be time-managed. The 8,700 sq ft structure was completed on schedule entirely during the school summer holidays.

The Carpenters’ Fellowship, which has an international membership, specialises in on-the-job training courses, along with the Construction Industry Training Board.

Students on NVQ schemes can be taught how to handle timber safely, as well as learning the traditional skills of carpentry.

Contrary to what might be expected, timber-framing does not require all the wood to be exactly straight. Straight timber is used for posts and beams but curved sections are needed for braces, struts and collars.

Mr Guiver said: “This is advantageous to woodland owners. Normally, people cut curved wood into firewood, but that is sacrilege as far as we are concerned.”

The Oxfordshire Woodland Project is working to make landowners aware that this option is available, and manager David Rees is encouraging them to improve the quality of standing trees to gain better returns.

In addition to good quality timber for beams, there is a demand for wood suitable for panelling and higher value veneers.

Buying timber locally is also advantageous for builders. By bringing a mobile sawmill to a woodland they can buy what they want, and cut out unnecessary transport costs.

Mr Rees said: “This increase in timber-framed building can benefit not only businesses in that sector, but other aspects of the local economy.”

One such business is in west Oxfordshire, where John Callen has established his timber construction company, Doodle Space, at Swerford, near Chipping Norton.

A specialist in furniture-making, with his own company John Callen Design, established for 15 years, in which he works with fellow-designer, Andrew Cartwright, he has found there is a new market in building in timber.

He explained: “I built a garden room, a green oak building, at home, which we affectionately call ‘The Barn’. It is clad in timber and has a sloping roof.

“The idea came from that, and now we can supply fully-furnished buildings, with underfloor heating and insulation for use all-year-round.

“We have put up buildings beside tennis courts for storing equipment, for use as artists’ studios and summerhouses for family activities.

“The panels are prepared here and then assembled on site, providing minimal disruption for clients. We try to give a six-week completion time, from receipt of order, with the assembly ideally taking about a week.”

Despite the current downturn in the economy, Mr Callen is finding there is still healthy interest from people who want to add this type of building to their property.

And the growth in the use of timber building has also been noted by Banbury-based architect and designer, Robert Franklin.

He takes an environmental approach when designing timber-framed houses for clients, encouraging them to plant ten saplings for every tree which provided the timber for their building.

While oak is often the timber of choice due to its colour and low maintenance, poplar and elm have been used, along with other species, such as larch.

CONTACTS: n The Carpenters’ Fellowship — call 0845 2011258, www.carpentersfellowship.co.uk n Oxfordshire Woodland Project — call 01993 814140, www.oxfordshire.gov.uk/woodlandproject n Doodle Space — call 01608 683323, www.doodlespace.co.uk n Robert Franklin — call 01869 338166, www.franklindesign.co.uk