That was awesome! I've now learned how I could make the windows look similar to what was there. I was also struggling with the roof and the pitch of the entrance and the side extension, which have the shed roof. I now see how I can change the pitch on those without affecting the roof over the house itself!!. Unfortunately, the house burned down in 1984 and therefore doesn't exist anymore. I have an architectural drawing from 1960 when the then owner added a shed to the shed that is on the left side of the house. So I'm drawing the house without that extension as my grandparents owned it from 1932 to 1955. The drawing is attached with some of the measures, plus the only color photo which is a water color painting that exists. The house had a roof space which I gather was around 1.5m in height with a steep staircase as the entrance. Thus I understand I can build a second floor, but lower the ceiling height. I've got the external and internal wall definitions configured about right. The external wall starts with corrugated iron (Yellowish/Orange colored), then you have pine strips of about 25mm (1 inch) thick, then you have tar paper and the frame studs, which are ca 5 inches thick. On the inside they had vertical panelling about 13mm or half an inch. I've configured this as the default external wall, plus the internal walls which were a bit lighter.
Thanks again, you have helped me immensely!! As I progress, I might ask further questions if you don't mind..