BUILDING WITH OAK FRAME
Oak homes are filled with character and wow factor – here’s how this method works
If you’re keen to create a focal feature out of your home’s structural system, green oak frame could be the perfect option. “It’s a versatile product,” says Mariyana Hartland, a chartered architectural technologist on Oakwrights’ in-house design team. “It brings quality and character to a new home, whether traditional or modern in style.”
The oak skeleton is constructed using a post-and-beam arrangement. Thermally efficient panels wrap the structure to create pre-insulated walls (known as encapsulation). Historically, wattle and daub or brick infills would have been used, however, 21st century self builders have numerous high-performing options, including conventional softwood framing and SIPS, at their fingertips. Many suppliers have their own high-tech encapsulation solutions that can be specified to meet your required level of performance.
Skilled workmanship
If you’re planning to build with oak, it’s worth consulting a specialist provider who has plenty of experience and is aware of the design possibilities and limitations. “Oak beams tend to span up to around 6m and we advise a bay width of around 3.5m,” says Lulu Greenhalgh-jones from Carpenter Oak. Larger open spans up to 8m or so can be incorporated – it just requires more complex engineering.
Careful detailing will also be required in glazed areas, as the posts and beams shrink and crack as the frame settles, forming the distinctive splits and shakes that give oak its innate charm. This is a natural part of the process, and the wood becomes more robust over time as a result. However, it’s important to employ a designer who is familiar with the process and can factor movement into the structural plans. “An experienced designer will also take into consideration the scales and proportions, load bearing and transfer of weight in the building so you don’t have posts in awkward places,” says Emyr Davies, director of Welsh Oak Frame. “Using an inexperienced architect could cause issues later on and design features expected by clients may not be achievable at construction stage.”
Off-site manufacture
As with other timber frame solutions, oak frame houses are built off-site in specialist workshops. The majority of the design decisions are therefore made up front, before the components are fabricated. Once the frame has been made, significant changes will be difficult to achieve – but you get a quick build on site. “When it is delivered, the structural oak frame could take as little as a week to erect. With the encapsulation wrapped around it, you could have a dry shell within four to six weeks,” says Mariyana.
As with all prefabricated builds, access is a consideration. While narrow lanes and difficult-to-reach sites can present a challenge for delivery lorries, your supplier may be able to load the structural components onto smaller vehicles to overcome the issue. Likewise, smaller lifting apparatus can sometimes be used as an alternative to cranes.
Costs
In broad terms, oak is acknowledged to cost a little more than softwood framing options, as you’re working with premium hardwood. Expect to budget anything between £2,000 and £3,000 per m2 for a fully finished house, depending on the level of specification you desire.