I once used some ordnance survey maps to determine some things about the land I was planning on building a house. I was asked by a good friend of mine to build his house for him and his wife. I had to consult those maps just to get the right information about what I would design. I ended up designing a really nice house with three bedrooms and two bathrooms and a large den. It took several months to complete but I was finished with the initial design within a month from when they asked me to do it. I am really glad I could do that for them.