To know whether we could afford to make a deal on the land we had to work out our build costs. Peter had a rough estimation of build costs and a friend gave us an excel spreadsheet of his own project as a guide. The homebuilding website gives a good guide and you can get an updated guide to the costs of self build today here (a lot more than when we set out!) As a guide to the developer costs he included costs around land acquisition – stamp duty and other taxes, lender fees and interest over the development period and fees for accountant, lawyer and land registry. Any costs for the road to extend utilities probably belong here.
Then there were professional fees, for planning, architects fees (7-15% build costs), structural engineer, probably an energy consultant engineer if you have to meet London Plan Carbon Reduction targets. Some of these fees such as the architects fees we would not need and I hoped I could take on the role of project manager saving us further (10%) costs.
A professional developer may pay a 1-2% finder’s fee for a lead on the plot and may feel entitled to a wage for his efforts. This we would not need to pay nor did we need to make a profit.