The amount of 2x4 lumber pieces required to build a home varies according to the size of the house, but it is generally recommended that there should be one 2x4 calculated per foot. Building code requires one every 16 inches.

To calculate the total number of 2x4s needed, one has to know the length of all of the internal and external walls. The length of each wall must be multiplied by three to account for upper and lower framing. Then the total number is divided by 16, the number of inches apart at which 2x4s are placed. This will provide the number of 2x4 pieces of lumber needed to build a house.