With a Self Build Mortgage you may be able to borrow up to 75% of the value or purchase price of the land on which the home is to be built. Usually the lower of the two figures is taken. You may also be able to borrow up to 75% of the value of the completed property (subject to status).
A wide range of repayment methods are available for a self build mortgage. Even if you own another property, you may still be able to get finance for your self-build project.
Regular finance with staged payments is available. You may be able to get finance to help buy your plot of land, then to help finance the construction itself with regular stage releases during the build.