Material Take-Off Lists From a House Plan
By Tim J. Davis
Ok, so you've purchased a piece of property and have a home plan and want to figure out the cost of building it. So what next? Maybe you are looking to get a job with a building contractor and material lists will be one of the things you'll need to know how to do. Well, here in a nut shell is how some of it's done. Most all that you need is a good understanding of math and a little patients.
For instance, let's say you want to know how many 2 inch x 4 inch studs are going into the walls. If you look at the details of your plans, you'll find out how far your studs are spaced. Most are at 16 inches on center. If this be the case, then say you have a 10 foot wall. There is 12 inches in a foot so simple math would tell you that there is 120 inches in 10 feet. Divide 120 inches by 16 inches and you come up with 7 and 1/2 or 7.5. Meaning you have seven and one half studs in the wall. Round that off to 8 and you have it.
How about the bottom and top plates? These are 2 inch x 4 inch pieces of lumber too. Looking at your drawing section you find that you have 1 - 2 inch x 4 inch bottom plate and 2 - 2 inch x 4 inch top plates. So you have 3 - 2 inch x 4 inch plates and the wall is 10 feet long so you will need 30 feet of 2 inch x 4 inch lumber.
Are you seeing how it works so far? Good! Lets take it to the next step. How about floor decking? If your room is 10 foot wide by 10 feet long that is 100 square feet. Right? You multiply the width by the depth. Sheets of plywood come in 4 foot by 8 feet sheets which makes 32 square feet. Divide 100 square feet by 32 square feet and you have 3 and 1/8th sheets or 4 sheets.
The same could be done for the exterior wall sheathing which is either OSB (particle board) or plywood. Lets say you have a 32 foot exterior wall that is 8 feet tall. The OSB or plywood comes as you know in 4 feet by 8 foot sheets. You could either divide the square footage of the wall, but we already know the wall is 8 feet high, or divide 32 feet which is the length of the wall by 4 feet, and you would come up with 8 sheets.
Of course the process involves counting windows and doors and their sizes, cabinet sizes and quantities, Light fixtures, plumbing fixtures, roof trusses and coverings, etc. And I know these were actually simple illustrations and it can be more complex, but this is the general method of material take-off.
My name is Tim Davis and I draw architectural plans for a living. I also teach Architectural Blueprint Reading at http://blueprints.8m.com