This is what I have come up with, drawings of the building, brick and also a section of the building. I had a look through the widow to see what's going on inside and estimate the floor heights etc..
Above are photographs of us visiting the site, bottom left shows how we used Pythagoras thereon to measure out the heigh of the building, using the laser tool. So what we did was we measured out bottom of the triangle, taking the tape measurer out 2 metres, then we used laser to calculate the distance from one end to the top of the building. 2000 x 2000 (the distance on the ground) then took away it from the sum of the longest side of the triangle, which gave us the number that was later on divided by itself, this gave us the height of that bay. We did this for every single bay. It was a good method to calculate the height but to double check I have counted every brick from the ground up.