Q: What is the principal energy source used by this household for space heating?

Ask for the principal fuel used by the household for space heating and circle the appropriate answer code. It is possible that a household may use more than one fuel at any one time but it is the one that is used most often that should be recorded. Only one code should be circled. Possible codes are as follows:

If the particular fuel used is not listed, write down the type of fuel used in the space below the codes.