Choosing a Build System
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The method you choose to build your dream home will have implications on practically every level of your project – from the speed at which it’s erected to the internal layout, not to mention the cost. From the hands-on familiarity of brick-and-block to the ultra-fast build speeds and super-airtightness of structural insulated panels, there’s something to savour in every system.
Local authorities are usually more concerned with the external look of your home rather than the build system at its heart. That’s because, at the end of the day, every new home has to meet Building Regulations – and every system is capable of doing so. Naturally, if you’re building in an area filled with timber-frame houses, planners and neighbours are more likely to be amenable to a similar build. But unless you opt for a really unusual route (such as an earthship) or your plot lies in a protected area, it’s rare to encounter any problems at planning level with this fundamental decision.
To help make things easier, we’ve put together a guide to each of the major build systems’ pros and cons – and highlighted a few of our favourite alternative routes to boot.
Brick and Block
This is still the most popular build route in the UK, accounting for around 70 per cent of all new homes. Brick and block consists of an outer brick skin and an inner block skin. The two leaves are held together with wall ties. Internal load-bearing walls are also made of blocks, while timber studwork is used for non-load bearing walls.
In the past, cavities were restricted to around 100mm – more than enough to satisfy Building Regulations, but nevertheless a limiting factor on insulation levels. Recent innovations in wall tie manufacture, however, have led to dramatic improvements. “We regularly deal with brick-and-block constructions involving cavities up to 300mm in width,” says Jamie Hayes, technical officer for insulation manufacturer Celotex.
Houses are built entirely on site, beginning with concrete foundations. Work progresses to first-floor level, at which point internal load-bearing walls are constructed and timber floor joists or a pre-cast concrete floor added, before continuing up to the roof.
Almost 22 per cent of all new homes are built using this method, many of them by eco-conscious self builders. In this system, the frame acts as a superstructure, supporting the entire building so there’s no requirement for internal load-bearing walls.
There are several different construction methods to choose from, including post-and-beam, green oak and conventional timber frame. In each case, the frame is prefabricated off site. Timber framing is a specialist skill, so don’t expect to get too hands-on with this part of the build. Most manufacturers require you to commission them to both fabricate and erect the frame, taking it at least to watertight stage – and some even provide a full turnkey service. Alternatively, the company may have a list of recommended contractors in your area.
Often, you can either choose from a range of standard designs, which can be tweaked, or ask your timber-frame supplier to work to bespoke plans drawn up by an architect. Design options range from ultra-modern homes clad in swathes of glass to traditional beamed properties.
Structural Insulated Panels
Structural insulated panels (SIPs) are made up of two layers of oriented strandboard (OSB) bonded around an inner core of insulating material. These precision-engineered panels are prefabricated in a factory, which makes for time and labour cost savings on site. When used for load-bearing purposes, they’re suitable for building walls, ceilings and floors. In fact, they’re so sturdy that they can be used to create truss-less roofs for liveable loftspace that make best use of available height – we’ve heard of many self builders who’ve combined other build methods with a SIPs roof for this reason.
SIPs is also growing in popularity as a wrap-around for structural timber frames, combining this system’s airtightness with the charm of internal exposed beamwork. Whether you choose a full SIPs build or a wrap-around, a successful project will result in an exceptionally airtight building envelope.
As the panels are lightweight, pile and pad foundations are appropriate, and will save you time at the construction stage. Experienced teams can erect the structure of a SIPs house in as little as three days (or seven to 10 days for a timber frame with SIPs wraparound). Other timesaving bonuses include pre-cut (or even pre-fitted) door or window openings.