An industry-approved software program should be used to calculate the heating and cooling load for the house based on the house plans. This takes into consideration the construction design features of the home, type of heating and air equipment, wall sizes, living space, doors, the number and location of windows and other criteria unique to the home. The heating and load calculation even takes into consideration the highest and lowest outdoor temperature experienced in a particular area and compares it with the customer’s desired temperature inside the home during both the summer and winter seasons.

It is highly recommended that metal ductwork be used throughout the home as opposed to “flex” duct. Metal ductwork sealed with duct mastic or a lifetime duct sealant, provides a permanent seal which makes duct leakage impossible. Flex duct and duct tape are temporary measures which eventually decompose over time increasing the probability of significant duct leakage.

For maximum energy efficiency (R-value and air flow resistance), soundproofing (from outside noise as well as room-to-room noise) and fireproofing, cellulose insulation is by far the best value. We recommended R -45 for the attic, R-13 in the wall cavities and R-19 in the floors.

Ideally, the heating and air contractor is also responsible for insulating and air sealing the house. If not, in the majority of cases the equipment will be over-sized. That’s because he has to size the equipment to make up for “the sins of the house”; otherwise they know the homeowner will be calling them when the home is not comfortable. Unfortunately, this also results in higher equipment costs to the homeowner then necessary, if the house were properly sealed and insulated.

Unless the builder can satisfactorily answer the question above they will not have a good idea of what it will cost you to heat and cool your home. And if that is the case, they will be reluctant to provide any kind of guarantee.