1) Build your house, complete with basic roof and all rooms that go under the roof. For this roof, use whichever edge you want.
2) Build a structure in front of your house that is one floor higher than your current house (so if your roof is placed on
top of the ground floor, build a 2-floor structure and so on. Remove the bottom floor of the structure, so you obtain a "lift" See also
this video3) place a new roof on top of the structure, this is preferably a one-sided roof for which you use elongated eaves. The edging is the semi-wide edge (not the full-wide, they will overlap and glitch)
4) lift or lower the structure floor so that the roof is positioned just below the basic house roof when it is one position removed from the side (you will need this to be able to lower the edge without placing the roof inside the first floorstructure of your main house)
5) Remove the small roof from the structure (first "float" it completely, not touching anything, THEN drag it into your house) and place it in its final location
6) Do the same for all following pieces of roof, each time lowering it one bit to obtain a nice edge.
7) If you want a wide edge, you might at some point need to move the tiny roof piece another square towards the middle to not drop it into the first floor.
Important!
1) If you want the sides of the roofs to show (the white band showing on the side of my building), build a complete room on the floor where you put your roof and remove the walls. If you do NOT want the sides to show (only roof edge present on the front), try not to build on the second floor or maybe only build in the middle and keep your roofs to the side.
2) If you build something (full walls or half walls doesn't matter) on the floor where you put the roof, you cannot edit the rooms (place/remove/edit walls) afterwards without the roofs disappearing, redecorating is no problem. If you do need to edit something, draw the "lifted" roofs completely out of the house, so they float freely before you edit and place them back afterwards.
