To safely work on your house, use scaffolding that you can build yourself. Nail a three-foot and a five-foot length of 2 x 4 at right angles. Then, make two three-foot triangles of 3/4-inch plywood, attaching them to the 2 x 4's with eight-penny nails. A double 2 x 6 will support your scaffold from the ground. Use a framing square to mark the angle. Cut, place in the triangle, and properly secure it to the wall and to the ground with a stake.
For more on construction, consider:
How To: Build a Sawhorse
8 “Unbreakable” Radios Ready for the Work Site