When I conduct the popular self-build talks and tours here at the NSBRC, I cover all aspects of build construction methods from traditional brick and block up to the latest insulated concrete form methods. To some, it’s a revelation that there are alternatives to brick and block and timber, whilst for others it’s an opportunity to clearly identify which is right for them.
So, being aware of the often confusing choice of build materials and always keen to educate, inform and inspire self-builders, I would like to present a brief insight into what materials you could use.
Funnily enough, some visitors to the Centre seem a bit worried about the use of timber frame and think this is a new way to construct houses! This is one of the most popular methods of construction with over 75% of new one-off self-build projects in the UK using timber frame and although there are many versions, they generally fall into open or closed panel systems.
With the growing importance towards energy efficiency, timber frame construction allows for better insulation and air-tightness, helping to achieve building regulations easier. Furthermore, the house structure can become what’s called ‘watertight’ quicker, adding to a more straightforward self-build.
Structural Insulated Panels (SIPs)
Used in the USA since 1924, SIPs can be classed as a closed panel timber frame system. This is another well-insulated and energy-efficient system. Panels are formed by bonding two outer skins of boarding to an inner core of rigid foam insulation, all of which is undertaken off-site in a factory before delivered.
The benefit of using SIPs compared to other construction methods is that the panels are rebated so that they can be fitted together, resulting in an airtight, insulated and loadbearing structure.
Like many non-traditional methods, a lot of design work needs to be considered at the outset as it can become costly and difficult to change after erected on-site because of the structural integrity.
Insulated Concrete Formwork (ICF)
Quick and easy to use, this system consists of stacking a number of lightweight polystyrene or neoprene blocks on top of each other to form the wall structure. Special mix concrete is then poured down the core of the block to form a solid airtight and well-insulated structure. The benefit of using this system is that the blocks can be easily changed or altered on-site before the concrete has been poured. However, after it has been poured it does become difficult and, from my own experience, it can be very painful trying to either drill through or form an opening!
Thin Joint System
A good alternative to a traditional masonry system. Comprising aircrete blocks with tiny pockets of air – which acts as a good insulator – these are glued together with a very thin layer of mortar to help achieve airtightness. This system achieves a high level of what’s called thermal mass within the envelope by absorbing heat during the day and then releasing when it gets cold at night, helping with the heating efficiency of your home.
The beauty of Thin Joint is that blocks can be easily cut to size on-site using a normal handsaw and with the development of external insulation, you can now also use this as a single block system.
There are other products of thin joint (mostly used in Europe) that consist of a clay block with voids created in its core, to help with the thermal performance. These blocks are generally known has Ziegel blocks or Thermoplan and information on this system can be obtained from the Centre.
One of the major obstacles in using a thin joint system is trying to find experienced and reputable contractors willing to use this material, which unfortunately may impact upon your build budget.
Traditional Masonry System
Then there is the good old traditional method of brick and block. This is still a viable ‘tried and tested’ material to use, but bear in mind that if you want to get to wind and water-tightness status quicker, you will need to ensure that the masonry is dried out before you move on to the different stages and additional costings may be involved for additional measures to gain building regulation approval. Again, it comes down to personal preference, with some of us liking the solidness and thermal mass properties of a traditional system.
In my opinion all these building systems work and perform in different ways. Take a careful look at your lifestyle, budget, energy efficiency and future considerations. Think about how you will actually build your home – if you are building out of timber frame, can you get a 40ft lorry and crane down to the site? Are there tradesmen willing to use your system? What work can you realistically do yourself? These are just a few of the questions you should be asking when trying to make a decision. The one best piece of advice I can give would be to visit us at the NSBRC where you can view all these systems under one roof, hopefully helping you to make an informed and correct choice.