- 1). Measure the height of each inner and outer corner of the house. Note the measurements in linear feet, add 10 percent to each of them and keep those figures handy so you can purchase all the inside and outside corner pieces you need.
- 2). Measure the borders around the windows, doors, soffits and other protrusions around the exterior of the house. Add all these measurements together and add 10 percent. Note this figure as the number of linear feet of "J" channel you will need.
- 3). Measure the length of all of the fascia boards around the house and add them together along with an extra 10 percent. Add all the heights of the fascia boards and add these figures. Multiply the total length by the total height of the fascia boards to get the total square footage of the metal needed to trim the siding.
- 4). Measure the length of every wall of the outside of the house. Add the lengths. Measure the height of each wall and add those figures. Multiply the total length by the total height to get the square footage of siding you will need for the job. Remember to add the extra 10 percent to compensate for waste.
- 5). Find the total length and width of each piece of soffit around the house. Multiply the totals of those two lists to get total square footage. Add 10 percent to that number and keep it handy so you know how many square feet of soffit siding you will need.
- 6). Take all of the measurements and figures to the supplier. Purchase all your materials, remembering to add that 10 percent to compensate for waste throughout the project.
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