What's the cheapest way to self-build?

I’m assuming from your question that you have zero intention of getting involved on a DIY basis. Just because you are a complete beginner doesn’t mean that, without some education, help from friends (particularly wise building friends) and determination, you couldn’t complete a house build through DIY. Much of the work involved on a building site day-to-day is relatively straightforward (particularly once you’ve got started), so if you have the time and inclination, don’t shy away from what seem like terrifying tasks: block laying, installing beam and block floors, laying roof tiles, fitting roof insulation, and so on.

If you were to go down this route, then in most instances you’d be looking at standard blockwork construction. If you have skills in the area, a ‘stick-built’ timber frame might actually be cheaper but it can be quite demanding to know where all the timbers need to go and is not really recommended for the beginner. Again, we’ve come across people who’ve built homes out of hay, mud, telegraph poles and plenty of other things besides — all of which were very cheap methods of construction, but none of which that realistic if you haven’t got some knowledge in the area (and a friendly Building Control surveyor).

So with a decent level of DIY dedication you can build a blockwork house for less than £500/m². That would involve you doing 90% of the work yourself. You’re also looking at a build time of years rather than months.

If DIY is not an option, then there is little to pick between regular timber frame and blockwork construction. Blockwork may be the slightly cheaper option purely because you might be able to source more local builders to compete against each other in the tender process and therefore reduce your labour costs. You could probably, without any DIY involvement and a very keen eye for prices, get a blockwork house built for £600-800/m². This would involve you sourcing lots of bargains. Remember, a lot of money in house construction ends up going on finishes such as kitchen units, sanitaryware and flooring.

And, one last bit of advice — build simple and build small. Don’t be too ambitious with your plans if you’re building to a tight budget — there’s a reason developers build tiny boxy homes! On that basis you should be able to build a home for £100,000-130,000.