Dai came up with a torch and told me in ten minutes that our chimney breast was the real problem. He was right, and nobody else had spotted it. Eight weeks later we had a bedroom and a shower room up there.
Reviews
What homeowners say.
Six sample reviews, including the one told no, and the one about the dust in the last week.

Six of them.
The drawing on the photograph is what sold us. We could see what the side of the house would look like, and we could argue about it before we spent anything. The new render has settled in well.
Our ridge came in at 2.02 metres. Bethan showed me the sums, said no, and wrote it down so that I would not be talked into anything. She suggested a ground-floor extension builder instead.
Five and a half weeks, as promised. They took the stairs seriously, which is where our neighbour regrets his. The lads hoovered at the end of each day when they were inside the house.
The room is great, but the last week of plastering and stairs was dustier than we expected, and the snagging list took a fortnight to finish. Dai came himself to do the last two items. No complaints about the build.
I am a builder, and I do not need telling how to do it. Bethan's drawings went through building control first time, and the steel calcs were right. I will use them again.
These reviews are invented for this demonstration site, like the business itself. We publish no overall score because we have no real one.
About the four stars
Sunil is right about the dust.
Cutting a staircase through a ceiling in a lived-in house is dusty, however much sheeting you use. We warn people now, with pictures, and tape the bedroom doors. The snagging list is a fair complaint as well: we now book the return visit before we leave and put the date in writing.

Go up with a tape. Then ask us up.
Measure joist to ridge and try the checker. Then book a free survey: Dai or Bethan will tell you what is possible, what it costs, and whether you should leave it alone.