How do I check how much roof space

[cocopops]

This is probably a daft question. We live in a terrace and most of our roof is flat except for a section at the front. We currently have no roof hatch but I want to explore whether it's worthwhile putting in roof ladder and getting what loft lwe do have floored for storage. How can I get the useable space checked - will I have to get some to cut out a section of roof in the bedroom or is the a more high tech way?

You could measure the height and angles then work out the volume. However, that won't necessarily tell you how much usable space there is because the location of beams and trusses will make a difference. The only way to actually find out if it's usable is to take a look. You don't have to cut a huge hole. Just one big enough to get a light and a camera through.

Any neighbours have lofts? If it is a normal kind of terrace (about 6 metres front to back) with a normal pitched roof, and a fairly old house, it's likely to have a decent loft. Even with trusses (diagonals all over the loft) you can get a fair bit of stuff in.

Knock on your neighbours and ask if the have had theirs done. Some terraces have a shared roof space. Victorian builders tended to save on bricks if at all possible ( I am assuming that it is Viccy)