The approximate breakdown of building costs is 45% materials, 40% labour and 15% for builders’ profit and overheads. So you can certainly make at least 30% savings by carrying out all of the work yourself. The problem is that most people don’t have the skills to do this. Even if you do, you could be looking at two years to complete the project and this is a bigger commitment than most people are prepared to make. You also need to take into account the loss of any earnings you might have otherwise been making while you’re occupied with your self-build. If you carry out part of the work yourself and employ labour for the rest, you could easily make savings of up to 20% in normal circumstances.