Following the completion of a timber framed house, that we helped design, we have been reflecting on how quickly it was built. The basic waterproof shell was erected in just two weeks and this is a big house, about 320m² / 3450 sq. ft. As the timber frame is a pre-fabricated construction system made in a factory, the component pieces are literally bolted, screwed and nailed together on site. A bit like a large-scale 3D jigsaw puzzle but with more organisation. As a result, the time on site is relatively minimal.
When looking at timber frame / pre-fab construction techniques something that is often overlooked is the pre-construction time and resources needed to design and co-ordinate everything to enable the products to be made in a factory. At face value timber frame buildings are erected very quickly but before this several weeks of design time, heavily detailed co-ordination with double checking of sizes and dimensions has taken place to ensure that everything is very accurate as late changes or errors can’t easily be accommodated. As we model everything in 3D with ArchiCAD this is slightly easier but it’s still time consuming.
We have conducted our own in-house independent research with quantified costings prepared by professional Quantity Surveyors and at the moment our conclusion is that a single one-off house can be completed cheaper and just as quickly using traditional methods of construction. This is mainly because the materials are cheaper and quicker to source and even with labour costs will often still work out cheaper than a timber frame system. The time required to complete construction can also be better as construction can start several weeks earlier without the need for the for such heavily detailed or co-ordinated design work up front. For a single dwelling this means that timber frame is probably not as economical as people often think.
Energy efficiency is often a reason cited to use timber frame but equal or better energy efficiency can also be accommodated [Passivhaus and better] with conventional building methods, especially with some of the new insulation products on the market.
Admittedly, the total embodied energy of timber frame is probably less as the amount of energy required / carbon generated to make masonry products and transport them is relatively high. However, this assumes the timber is sourced from UK grown forests and not imported and shipped over from foreign countries, which is often the case, which may actually mean the carbon generated from the timber could be higher.
For larger scale buildings or volume estates of ten houses + then timber frame construction or alternative pre-fab methods will definitely have a benefit as the overall time taken could reduce by several months which would equate to a major cost saving.
We hope this gives you an objective and helpful understanding of timber frame construction.
Contact us about any questions you may have or how we can fulfil your requirements