DESIGNING a timber frame home
Find out what you need to know to commission a successful scheme for your timber frame self build
Panelised framing systems are right up there with masonry as a leading, cost-effective structural option – offering a host of benefits in terms of build speeds, price certainty and easy detailing for energy performance. Here’s how to go about getting a bespoke design that will suit your requirements.
Who designs timber homes?
Any architect or house designer worth their salt should be familiar with this construction method and capable of coming up with an appealing scheme that looks to take advantage of its innate qualities. Indeed, many impressive self build projects are realised in this way. That said, your timber frame supplier will want to be involved as early as possible to ensure the outline plans can be translated into a buildable, value-engineered reality – and they’ll aim to work alongside your architect to ensure the practice understands the intricacies of the exact system they use.
Many companies now offer an in-house design and build service for your entire project, from plot appraisal and planning through to shell erection and – in some cases – right up to completion. In fact, some prefer to work this way. “It can be refreshing to partner up with an external architect, but we’ll usually have to redraw the planned scheme to check its viability and what the cost will be,” says Oliver Rehm from Baufritz. “For that reason, we normally do the full design service ourselves. Our architects are trained on our system, so they know what’s possible and what things cost. We find it makes for a smoother process.”
What kind of house can I have?
The sky’s the limit – this is a truly flexible method, allowing you to create a home in pretty much any style that’s totally tailored to your needs, design tastes, budget and the demands of your plot (or the whims of the planners).
Externally, lightweight cladding systems such as timber, fibre-cement, render or brick slips make sense to support timber frame’s quick build speeds. But you can happily switch to a full brick or stone outer leaf should you wish. See www.self-build.co.uk/cladding-timber-frame for more on the options for finishing this type of home.
Internally, wow-factor architectural features such as open plans and vaulted ceilings are easy to achieve. “We can basically produce anything,” says Oliver. “Rectangular structures are of course straightforward and cost-effective
to manufacture, but complex geometry is getting more popular. Many self builders are looking for something that’s organic and avant-garde – and we can do curves, eaves overhangs, triangular forms and more.”
You can even combine the panels with other structural materials, such as glulam (an engineered, laminated timber beam) or steelwork, to deliver features that can’t be costeffectively achieved with standard framing alone. “If we want to shape something or create wide spans, we prefer glulam for sustainability reasons – but sometimes you just need to use a piece of steel,” says Oliver.
Where can I find inspiration for my timber house build?
Most frame suppliers maintain a book of past projects, which can be a good place to start when it comes to coming up with initial ideas. You may even find a scheme that can form a template for what you’d like, with some tweaks to better suit your needs. It’s well worth logging on to the reader projects section of the Build It website, too, at www.self-build.co.uk/homes.
But the best way to get a feel for the quality you can expect from a particular supplier – and to experience layouts, room sizes, products etc – is undoubtedly to visit completed houses. Potton’s self build show centre in St Neots offers five homes to explore, for instance, with a range of architectural styles and performance levels.
“We always want people to come to our showroom to get an idea of the product we offer and a sense of what’s possible,” says Oliver from Baufritz. “We also invite people to visit our customer’s houses – whether at building stage our finished – so they can see different styles and budgets.”
Does the type of frame specified affect the finished design?
In terms of the look and feel of the house you’ll end up with, there’s very little difference between the two main types of timber system. What might change is how much of the design work is done by a single company, and how you procure the engineering and supply of follow-on components (see the next section for more on this).
Open panel frames are manufactured with the internal side of the walling elements left unsheathed – so this route can give a feeling of greater choice and control during the build. In some cases you can even specify and fit your own insulation, should you wish. Much more popular these days, however, is closed panel framing, where the wall sections are supplied to site as complete products, with the insulation (and sometimes more) pre-installed. This level of factory control is generally considered to be a more straightforward route to good energy efficiency, and will deliver a faster build on site.
What do suppliers typically include in their timber frame packages?
This will depend on what level of service you’re going for. A structural design and shell erection package will comprise the load-bearing wall panels, internal partitions, roof trusses, engineered floor structures, and all the other components (such as breather membranes, sealing tapes and, usually, the insulation) required to build the main structure. It will also include the labour to raise the frame.
Some firms are able to pre-fit the likes of windows, doors, service channels, internal and external finishes to your specification as part of the supply of a closed-panel house shell. This will dramatically increase the speed of construction but does require you to bring forward a lot of the detailed specification phase. So you’ll need to nail down the exact location of sockets, switches, sinks, WCS and the like to enable manufacture of the frame.
A number of timber home suppliers offer a project managed service, giving you access to experienced assistance deeper into the build. The likes of Baufritz and Sylva can provide what’s known as turnkey delivery of your house. So once you’ve specified the design and finalised the plans with them, they take care of pretty much all the work on site – although the groundworks and foundations stage is typically down to you to arrange. You’ll usually be left to choose your own kitchen, too, given this side of the industry operates on a supply and install basis.
Can I change the design on site?
While it’s possible to alter your plans as the build progresses – provided they still accord with the planning consent – this is generally best avoided, whatever construction system you’re using. Major changes will inevitably add delay and extra cost to your scheme – especially if modifications to the house shell require structural calculations.
Your goal, therefore, should be to nail down the design as far as possible before you break ground, so that any on site alterations are kept to a minimum. To do this effectively, you need to be able to visualise what you’re getting, so it’s worth asking your designer to produce interactive 3D walkthroughs (which are pretty easy to produce these days thanks to the likes of Sketchup and Build It’s 3D Design Software). This will help you understand how you’ll interact with the living space and give you the opportunity to make tweaks before you green-light the structural plans for manufacture.
The bespoke design for this 200m2 contemporary project was drawn up by Potton in-house architect Vicky Corbett Above: Chris and Sheila Marwood chose home building specialist Hanse Haus to deliver the structural design and most of the building works for their architectplanned scheme in Cornwall. The shell erection and main fit-out was completed in just 12 weeks
Above: The design for this self build project in Essex was a close collaboration between owner and retired chartered surveyor Peter Granger, who created the initial sketches himself, and the team at Scandiahus. The frame was supplied as a shell build package