10 reasons for considering timber frame
Above: The Elsworth, built to Passivhaus standard, is one of the homes at the Potton Self Build Show Centre in St Neots.
1 Speed of erection
It is no surprise that timber frame is the construction method of choice in Scotland and Scandinavia where the wet climate can restrict on-site build time. A timber frame is usually constructed in a factory and then delivered on site where it is erected and made wind- and weather-tight in a matter of days or weeks, depending on the complexity. This allows internal work to continue regardless of the weather. There is usually a lead-up time of six weeks, though 12 weeks is not unusual, for the company to supply the frame. This period can be spent preparing for the build so that this time needn’t be lost. Once on site, the build should progress relatively smoothly, as the groundworks will have been done and the overall construction time to completion is usually six to eight months. This is comparable to a conventional brick-and-block build in fine weather, but you can be guaranteed that there will be few delays down to the vagaries of the weather.
Most house designs can be adapted to suit a timber frame. However, it is wise to consult a manufacturer as early as possible to see how your design can work best with the frame. Many timber frame companies offer a design service as part of their package, with some offering tried and proven house ‘standard’ styles that can be tweaked for clients’ specific requirements. In the case of Potton, one of the biggest manufacturers in the UK, clients can visit their Self Build Show Centre to see the various styles at close range.
Timber frame suppliers can be loosely divided into those offering panel walls and those who provide post-and-beam designs – where the weight is borne by heavy timbers and the external walls provide a protective layer of weather-proofing. Externally, the frame can be clad in almost any suitable material such as brick, stone, rendered blockwork or timber/synthetic cladding,
Due to their lighter weight, timber-frame systems are particularly suited to brownfield sites with poor soil conditions.
Similarly they can be employed for upstairs extensions, where existing foundations are to be used.
Timber frame manufacturers are used to supplying and building houses, so they usually have timings and planning down to a fine art. This can take a lot of the stress out of a build. As well as the design, a timber frame company can organise planning applications, Building Regulations drawings, and even deliver the completed house as a turnkey project. In some areas, such as on custom-build sites, they can also provide the plot.
4 Mortgages and finance
It seems ludicrous to think that there was a time when lending institutions were reluctant to finance a timber-frame build. These days, mortgage companies like the reliability and predictability of this method of construction, especially if they know the frame is being supplied by a reputable company which can work with you to draw up a realistic schedule to meet your lender’s requirements. Just remember that the frame will need to be paid for upfront, which will have implications on your cash flow.
The average timber frame accounts for around 20-30% of the total cost of a build. Timber-frame construction allows great flexibility to suit different budgets and aspirations, from standard-spec kit packages to fully bespoke architect-designed projects.
Some companies provide an online cost calculator where you can get a ballpark figure for the kind of home you want to build.
Over and above the structural frame, suppliers can also provide windows, external doors, internal doors, plasterboard, insulation, staircases, skirtings, architraves, and so on which not only makes your build simpler to manage, it also allows you to prepare a more accurate budget. Other services such as planning, building warrant, engineering and SAP calculations can also be provided as part of the package. It is worth bearing all this in mind when comparing quotes from frame suppliers. There are more companies in the market than ever before, so be sure to shop around. And make sure you know exactly what is included in the price.
Unlike most other construction methods, timber frame offers selfbuilders the option of being involved in the build as much or as little as they like. Indeed, timber frame companies have come a long way from only supplying ‘kits’, leaving the client to sort out the rest of the build. These days, many companies offer a full range of services from the supply and erection of a wind- and water-tight shell, right through to a turnkey service where they take care of everything, right through to completion. There are many other options too. For example, timber frame specialist English Brothers coffer:
- supply and erection
- groundworks, supply and erection
- groundworks, supply, erection and temporary watertight package
- groundworks, supply, erection, complete watertight package (outer cladding, roofing and window and door installation)
- full build
- project management.
Above: A typical timber frame, in this case supplied by Fleming Homes.
Over 85% of homes in the developed world use a form of timber construction. Timber is the most sustainable structural building element, so it follows that timber frame is one of the greenest construction methods.
A renewable, non-toxic and completely organic material, timber contains less embodied energy than concrete and steel.
The timber for your frame should be sourced from well-managed sustainable forests, so check that it carries the appropriate certification – Endorsement of Forest Certification (PEFC) or the Forest Stewardship Council (FSC). It should also be noted that there is likely to be less on-site wastage, as all the timber will be pre-cut in the factory. This will have a knock-on effect with your skip requirements.
8 Energy efficiency
Timber-frame technology has moved on in recent years to meet the stricter energy-efficiency requirements demanded by Building Regulations. The essentially hollow shell can accommodate high levels of thermal insulation which, together with general improvements in construction skills to achieve highly airtight structures, have resulted in more energy-efficient homes.
9 Cost efficiency
Timber frame construction maximises cost efficiency, mainly due to speed and accuracy. Time is money, after all, so the less time spent on site can often mean a more cost-effective build. Likewise, because timber frame projects are designed and manufactured off-site, cost deficiencies can be addressed early in the design process.
There was a time when many would have scoffed at timber frame, dismissing it as noisy, flimsy and not as good as traditional brick and mortar. Not any more. Selfbuilders have led the trend for timber frame for several decades now, with many of the major housebuilders following suit.
Timber frame is seen as a precise modern method of construction, which eliminates much of the on-site guesswork associated with other building methods.
Some companies take their off-site fabrication one stage further and offer a closed-panel system, with insulation and vapour-control barriers pre-fitted in the factory. Openings are incorporated in the fabrication, with doors and windows usually fitted on site to prevent damage in transit. Closed-panel systems are usually more expensive than open panels, but faster to erect on site and they can achieve excellent airtightness levels. Problems with noise, once seen as a major disadvantage of timber frame over masonry, have been addressed with improvements in acoustic insulation and good detailing. For example, poured screed on timber floors and heavier wall linings can be used to create a quieter home though the additional cost of materials should be taken into consideration in your budget.