i had a mate of a mate do my dormer window as he is a carpenter. He did the whole dormer (5m x 3m) built and clad in plywood in two days and cost me £140 per day. I was very impressed. He recommended the bricklayer as he works with his brother and said his work is ok. It's a pretty simple job to be honest. All he has to do is carry on building up but it'll be good if he can get it finished in a day. The wall i've build is absolutely fine but i take my time and am quite slow. A professional shld get it finished in a fraction of the time it'd take me