Do it Yourself: House Addition

Permits and Preplanning

• The first thing you should do before you begin constructing a house addition is secure all necessary permits. You can obtain your building permits from your city building inspection department--usually located in the city hall or city governmental building. Once the permits have been secured, you may be required to perform a soil test to ensure that the soil onto which the new addition will be constructed can withstand the new construction. If the soil test fails, don't fret. You can upgrade the soil with crushed stone hauled in from your local supply store.

Calculating Material

• You should be well versed in calculating material. If not, carry your plans or addition measurements to your local builders supply store. The construction estimator who works for the supply store can calculate the material amounts and costs. This service is usually free of charge--carry your business elsewhere if the supply store wants to charge you for estimates. The good thing about having your local hardware store/builders supply store calculate the material amounts and costs is that they are putting their word on the amounts of materials and costs. See the resources below for figuring your own material costs.

Building

• When building your own house addition, make sure the footers are sufficient enough to support the walls. Footers that are 16 inches wide and 12 inches deep are usually good enough for single-story walls. The block or concrete foundation walls, if they are below ground, should be coated with tar sealer on the outside before back filling.

  Frame the floors with manufactured or regular lumber that is no less than 10 inches wide. The framing for floors should be 12 or 16 inches apart, and the floor decking should be at least 3/4 inch thick. Frame the walls--using 2-by-4 or 2-by-6 boards--at 16-inch centers. And make sure you insulate the walls and floor with the appropriate insulation thickness. The roof should be framed with 2-by-6 or 2-by-8 lumber and spaced 24 inches apart. Remember to cover your finished roof with felt paper in order to protect the wood until you are able to apply roofing.