What is involved in buying a plot and building your own home?
Considerably more than buying a house — you take on the roles of developer, project manager and client simultaneously, and the risks concentrate in the land purchase, which is where most self-build projects fail before anything is built.
The land, which is the hard part:
Planning status. A plot with outline planning permission establishes the principle of development; full or detailed permission approves a specific scheme. Land without either is a field, and buying it hoping for permission is speculation.
Conditions attached to permission, which can be onerous and expensive — access improvements, drainage, ecology surveys, contributions to infrastructure.
Services. Connecting water, drainage, electricity, gas and telecoms can cost far more than expected, and a plot that is not already served may require crossing land you do not own — needing easements you must secure.
Access rights, which must be legally sufficient for construction traffic as well as for a dwelling.
Ground conditions, contamination, flood risk, trees with preservation orders and archaeology, each of which can add substantial cost.
Covenants, which can prohibit building entirely regardless of planning permission — planning permission and the right to build are different things.
The build routes: a main contractor on a fixed price; a package company supplying a kit and managing the build; managing trades yourself, which saves money and consumes an enormous amount of time; or a hybrid.
Money, which works differently:
Self-build mortgages release funds in stages, either in arrears after each stage is complete — requiring you to fund the work first — or in advance, which is more expensive and much easier to manage.
Contingency, commonly advised at 10–20% and routinely spent.
VAT. New-build dwellings are zero-rated, and self-builders can reclaim VAT on materials through a specific scheme — with one claim, after completion, within a deadline. Records must be kept throughout.
Building control, warranties and insurance are all required, and site insurance is not the same as household insurance.
Right to Build registers oblige some councils to make serviced plots available.
General information, not legal or financial advice.