With yet more help on a slotcar forum my layout has progress as it was thought that my view might be blocked on some of the corners from where i will stand,so i have made some changes and now have this design and it is still within the area i will use but if i have it setup over the weekend part of it will have to be removed so i can get into bed as it over hangs my bed by 1ft 5".
And when i come to make the framework it has to be light and easily dismantled into sections to be stored as it won't be a permanent layout.