I love cutting these house shapes in one piece.
Of course, there's the method of using 4.5"squares, and adding 2.5"squares to both top corners with the flippy method.
I prefer to cut the house shape with my Easy Angle ruler, either the 6" or the 4" one, because they are always on the cutting table anyway. The numbers aren't relevant for this sort of cutting, so to find the line I want, I use a strip that is the size of that corner triangle; 2.5" triangle, so a 2.5"strip.
I start with a 4.5"square, and trim off the top corners to make my house shape. I'll cut the one on the right, then flip the squares over to cut the other side. I can flip the ruler, but then the markings are on the top of the ruler, and that drives me nuts because it's not accurate; I ALWAYS cut with the markings on the bottom, right next to the fabric, not floating an eighth of an inch above it.
There are other rulers that you can use to cut this shape; an oldie but a goodie is by Trudie Hughes;
Rotary Mate has these Speedy shapes along the edge, and they are for trimming off corners, very useful for making house shapes, or octagons. The ruler is so easy to use; if you have this in the cupboard it's really worth dusting it off.
Then there's this ruler, from Creative Grids. It works fine too, but it's more expensive than the other two rulers.
Elongated Hexagon with this ruler. (This is the same quilt that Bonnie is doing as a Leader Ender; my measurements are here.)
Of course, once I have my house shape, I need 2.5"triangles to add to the corners. I cut mine with the Go Cutter, but if you don't have one, cut them with the Easy Angle. (Not from jellyrolls, those pinked edges drive me insane.)
I add the right-hand triangle first, lining up the flat tips with the top of the house shape and the side, and pressing the seam towards the triangle.
The finished unit should measure 4.5" square,
If you want to make other sizes, it's easy to figure out. The triangles will measure half the square; for a 3" finished house block you would need 1.5" triangles; the cut sizes would be 3.5" squares and 2" strips for the Easy Angle. For a 6" house unit, 6.5" squares and 3.5"strips, and so on.
I might just go through Blockbase and see what patterns I can find with this shape; I'm not sick of making them yet, and it's a nice shape to use charm squares. Heaven knows I have enough of those hanging around.