At first I thought the extrusion would work easily, and it does appear so, however it took time to correct the lines, I had to modify through the vertex tool.
After building the walls using the clone tool. I needed to adjust some parts and elements, as they did not match up very evenly. This was a problem I faced and had to solve by re-measuring and moving the walls slightly. I am still not 100% happy with the result however, I didn't want to spend a lot of time tweaking them. If I have time at the end of the project I'll change little parts of the structure.