OK I've finally started work on the internal room... Fortunately this is a bank holiday weekend so I'm able to spend a few hours constructing. The first task I set myself was to construct the left hand wall stud work and the aim is complete it this weekend. Having cut and marked out the soleplate for the wall I drilled five 10mm holes for the through anchor bolts to secure the wall to the concrete floor. I then positioned the plate in situ and marked through the holes into the concrete with the masonry drill. I then removed the plate to complete the drilling, I needed to drill holes 2" (about 50mm) deep into the concrete for the anchors. This actually started off pretty well but at about hole number four proved to be impossible to drill. There turned out to be a hard stone (part of the aggregate in the concrete mix near the top) exactly where I wanted to drill. I completed all of the others and decided to drill a new hole in the plate and hope this was in a better location! Fortunately this was successful and was able to drill the 2" pretty easily.
Once this was done I positioned the plate with vinyl between the plate and the concrete floor. I drove the anchors through the wood into the holes in the concrete with a bash from the hammer until they bottomed out. I then tightened the nuts and the plate was well and truly anchored to the floor. I then cut the upright studs for the wall as per my design drawings with the 7 degree angle at the top. These were then screwed into position on the soleplate.