hi i would like to know how to build a wall to a specific measurement. when i make a wall in project mode i find it really hard to drag and drop the walls to the measurements i need and i would like to know if i can just input a measurement i need the wall to go to so for example. my wall is 4m long with a chimney stack pertruding by 400mm and 2m wide. if you could show me the best way to go about this that would be great. also in relation to this i would like to know how to input a window to the right hand side alcove back wall at 700 x 700mm