Doing the work yourself
Another option is to do most of the building work yourself.
This saves you money and gives you the most control over the build, but it's extremely hard work – especially if you haven't done it before.
Because of this, most self-builders either do none of the work, or only smaller parts (like the interior decorating).
If you're sure you want to do most of the work yourself and have someone to help you (since many jobs need more than one person), there's a wide range of self-build websites and books that can give you guidance.
There are also courses, workshops and seminars available to help you learn the skills you need. You can find these on self-build websites or at housebuilding and renovation shows.
Unless you have the right qualifications there are some parts of the work you'll need to hire professionals to do, like electrical and gas work.
It may also be worth getting Approved Certifiers of Design or Approved Certifiers of Construction to do some of the work for you. They'll be able to give you certificates guaranteeing their work is safe.