SHELTER: ECO-DESIGN IN THE REAL WORLD MATH WORKSHOP #1

List any assumptions that you make to arrive at a solution for each problem.

You want to build a straw-bale building that is 16 by 20 feet. You pour your foundation with a 6-inch stem wall that you will build on top of. You want 8-foot walls. The peak of the roof on your straw-bale building will be six feet above the top of the wall, with the ridge beam running parallel to the long wall. Your plan calls for a 2-ft overhang on each rafter.

1. Given that your bales are 3 ft long and 1.5 ft wide and high, how many bales do you need to order?

 

 

2. How long will your rafters be and what standard length of 2 by 8 do you need to order?

 

 

3. If you space the rafters every 24 inches, how many will you need?

 

 

4. How many 4 by 8 sheets of oriented-strand board (OSB) will you need to cover the roof

 

 

5. You will need to build a top plate on your straw wall. Having the top plates exactly parallel and square will greatly simplify building the roof. Describe how you might align two long 2 by 6 boards on top of each wall to insure that they are exactly parallel and square on all four walls.

 

 

6. Estimate how much time you have (or will have) spent brushing your teeth by the time you are 30 years old.