How should one/does one usually do it, should you choose a wider window reveal board so that it extends beyond the wall and can also function as a window sill? If we set them flush with the wall, they will be 140mm deep, but you could make them wider, around 200 at least? But then solid wood is required, not MDF there?
Or should one place a window sill outside the window depth? There is no reason for this if you don't have any radiators underneath?
Or should you have them only 140mm deep perhaps?
