6 Construction Systems for Your Self Build Project

The method you choose to build your dream home will have implications on practically every level of your project – costs, build speeds, internal layout and energy efficiency are just some of the areas that could be affected.

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:

1. Brick and block

Modern masonry 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. These 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, wall 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.

Masonry 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.

Build speed: Around 20 weeks for a three-bedroom home (180m2). Site work progresses slower than alternatives such as a timber frame, but lead times for materials are drastically reduced.

Cost: Around £80-100 per m2 for the blockwork, cavity insulation, brick outer wall, lintels, wall ties and cavity closers.

2. Timber frame

Around 25% of all new homes are built using panelised timber frame, many of them by eco-conscious self builders.

In this system, the frame acts as a superstructure, supporting the entire building. So there may be no requirement for internal load-bearing walls, freeing up space for open-plan layouts.

The frame is prefabricated off site, giving you the reassurance of a factory guarantee that the high-quality finished house shell will deliver the performance you’re expecting.

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.

Some timber frame suppliers even provide a full turnkey service for your bespoke self build home, where you agree the design and they complete all the works for you. 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.

Build speed: A timber frame home can be erected and made watertight in as little as five days.

Cost: Around £90-120 per m2 for the structural frame.

3. Insulating Concrete Formwork

If you enjoyed playing with building blocks as a child, then insulated concrete formwork (ICF) could be for you.

Basically, ICFinvolves stacking a series of hollow blocks, which interlock to create a mould that can then be pumped full of ready-mixed concrete for an ultra fast build. The resulting walls are pre-insulated and super airtight.

Common block options include expanded polystyrene (EPS) and bonded wood fibre, while panelled versions are also available.

Using an experienced ICF installer is the best way to ensure project success. But with a little training, which is often offered by ICF suppliers, self builders can get very hands-on with building work.

The trick to proper construction is getting the first course absolutely plumb, level and square. It’s well worth getting professional assistance at this stage to set the pattern for the rest of the work, as any misalignments tend to get amplified as building progresses.

ICF is a quick build system, so even if you employ skilled workers for the duration of the project you should still save on labour costs in comparison to brick-and-block.

Once the concrete pour is set, the structure can then be finished in your choice of cladding. Render, for instance, can be directly applied to the polystyrene blocks.

Build speed: Basic structure can be up in a matter of days.

Cost: Around 5% higher than for a typical brick and block build.

4. Structural Insulated Panels

Structural insulated panels (SIPs) are very similar to timber frame. They are typically made up of two layers of oriented strandboard (OSB) bonded around an inner core of insulating material.

The precision-engineered panels are prefabricated in a factory, which makes for excellent quality control along with  time and labour cost savings on site.

When used for load-bearing purposes, they’re suitable for building walls, ceilings and floors.

In fact, SIPs panels are so strong 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.

These SIPs panels are provided by Kingspan

SIPs is also growing in popularity as a wrap-around for green oak frames, combining this system’s airtightness with the charm of internal exposed beamwork.

Whether you choose a full SIPs build or a wrap-around, this system will deliver an exceptionally airtight and highly insulated building envelope. This can make energy-saving standards such as Passivhaus easy to achieve.

As SIPs panels are lightweight they’re quick and easy to crane into place, which will save you time at the construction stage. Experienced teams can erect the structure of a standard SIPs house in as little as three days (or seven to 10 days for an oak frame with SIPs wraparound).

Other timesaving bonuses include pre-cut door and window openings (much like with timber frame).

Build speed: Can be even faster than conventional timber frame on site, but prefabrication of panels takes around 10 to 12 weeks.

Cost: Can be around 15 per cent more than a standard timber frame up front, but you’ll save on labour costs and heating bills.

5. Oak frame

Oak frame is a historic structural system that remains as popular as ever amongst today’s self builders. The characteristic warmth and visual charm of oak works well in both traditional and contemporary builds.

What’s more, many oak frame suppliers now provide a bespoke architectural service, meaning that homeowners can enjoy a seamless design and build process.

Although this method of construction typically adds roughly 10% to structural costs, you can still build an impressive oak frame home on a range of budgets with carefully considered design.

For the frame to meet modern performance standards, it is usually encapsulated to create a highly efficient thermal envelope. This might be done with SIPs or another pre-insulated panel system.

6. Thin joint blockwork

This is a variation on conventional brick-and-block. For self builders, the immediate appeal is that construction speeds are much quicker than standard masonry, assuming you use a contractor experienced with the method.

That’s thanks to the use of quick-drying 3mm mortar lines as opposed to 10mm for traditional masonry (hence the name ‘thin-joint’) and the optional use of oversized aircrete blocks.

Aerated for lightness and to improve their insulating qualities, aircrete blocks are surprisingly strong, and can even be used for foundations.

This system shares many of the advantages of brick-and-block. For example, it’s relatively easy to adapt or extend a thin-joint home.

Labourers should be fairly easy to come by, too, as brickies only need a little retraining to acquaint themselves with the technique. In fact, most trades should find working on a thin-joint home to be a familiar experience.

The use of thin mortar beds allows for greater build accuracy, which means time-saving thin-coat spray plasters or renders can be applied to finish the walls inside and out.

Build speed: A standard design could reach weathertight shell stage in around five to 10 days.

Cost: Likely to come in 5% higher than standard brick-and-block due to increased material costs, although labour savings on large projects may bridge that gap.

Main image: Oakwrights