The mortgage, which replaces Saffron’s existing self-build product, is offered on a discounted rate of 4.20% for 24 months.
Borrowers can draw down funds as required and are no longer restricted by inflexible stage payments. Saffron will also accept applications from first-time buyers.
The product has a 1% arrangement fee and a minimum and maximum loan size of £30,000 to £1m.
Anita Arch, head of mortgage sales at Saffron, said: “We’ve listened carefully to feedback for self-builders, who tell us they want to keep mortgage costs to a minimum during the build period and that they also want the flexibility to draw down funds as and when required.”