Regulations are generally much more detailed than the law. If there is a conflict between the law and the regulations, the law has more authority. The regulations set the state standards for the maintenance of heat, responsibilities of owners and occupants, enforcement, etc. Case law Courts at both the state and federal levels are likely to have ruled on questions about the federal and state laws. The law as it was initially passed is shaped and refined by these court cases.
Case law can be tricky to apply.
Some court decisions apply only to situations where the facts exactly match the facts of the case that was decided. In other cases, the court makes a decision on a general principle that may apply to many situations. Use case law to give you an idea of what a judge might decide but remember that your facts must fit exactly in order for the case to apply to your situation. An attorney can help you make this kind of analysis.