It makes sense to include energy-efficiency features in a house as it is built, rather than renovating later. Key features such as high performance windows, high efficiency heating systems, extra insulation, and proper air sealing are much cheaper and easier to build into a new house than to add to an existing one. And all new homes built in Montana must meet the current energy codes.
Montana homeowners can take advantage of the $500 energy conservation tax credit (per taxpayer) to lower your first costs when you build a home that is above the building code. Saving money on your taxes is nice, but most individuals feel the increased comfort alone is a good reason to build an energy-efficient house. Energy-efficient houses are draft-free, resulting in uniform temperatures throughout all rooms. Lower space heating requirements over the life of the house saves you money each month and protects the homeowner against increases in the cost of energy supplies.
Frequently Asked Questions
Yes, the requirements of Montana energy code apply to all new Montana houses, additions, and renovations. Exceptions are: buildings that are neither heated nor cooled; farm and ranch buildings; any private garage; private storage structure attached to a home; buildings that are classified or determined to be eligible for a listing in the National Register of Historic Places; and Housing and Urban Development (HUD) code manufactured homes.
Montana adopted the 2012 International Energy Conservation Code (2012 IECC) with Montana amendments on November 7, 2014.
A summary copy of the 2012 IECC with Montana amendments is available through the Montana Energy Code website. A copy of the 2012 IECC is available from the International Code Council or by calling: 800-786-4452
Energy code inspections are conducted inside the city limits (jurisdictional areas) of the larger Montana cities and the counties of Silver Bow, Richland and Anaconda/Deer Lodge. A listing of certified cities/jurisdictional areas is available. Outside these jurisdictional areas, builders are required to build to the energy code standards and participate in a self-certification compliance program. The program requires that the home builder document energy code compliance in writing. In most cases this is accomplished by signing, dating, and attaching an energy code compliance label to the home’s electrical panel box.
Yes, the credit is 25 percent of the cost (material and labor) for qualified high efficiency heating and cooling equipment such as a 95 percent AFUE furnace and the extra cost of components and insulation that exceed energy code levels. The Montana Tax Credit Brochure can be consulted for details.
If your house is built inside a certified city/jurisdictional area with code inspections, your house should meet code. In some cases the home’s lender may conduct building code inspections; check to see if your lender plans to do an energy code inspection. Another option is to have the house inspected by a Home Energy Rater. While a Home Energy Rater can’t officially certify a home as complying with the energy code, the inspector can provide an evaluation similar to that of a building code official. Find out if your builder plans to fill out, sign, and attach an energy code compliance label to the home’s electrical panel.
Houses built to code will have lower heating/cooling bills, fewer drafts, and have reduced chances of damaging moisture being trapped within ceilings, walls, and floors. The energy code sets minimum levels for insulation, windows, air sealing, heating/cooling equipment, and mechanical ventilation systems.
Yes. The blower door test consists of a large fan assembly temporarily placed in an exterior doorway. With all windows and doors closed, the fan is turned on, drawing air out of the building. By measuring the air flow required to hold a slight vacuum in the house, an air tightness rating can be obtained and used to evaluate the effectiveness of the air sealing measures. A blower door test is a way to confirm that the air sealing requirements of the Montana Energy Code have been completed. The blower test results should be listed on the energy code compliance label and be 4 air changes per hour at 50 Pascal pressure (ACH50) or less. Companies and individuals perform blower door tests.
Not only is an oversized system more expensive to install, but the increased cycling on and off of oversized equipment can increase energy bills, equipment maintenance costs, and shorten the life of the appliance. It is especially important to size an air conditioning system correctly, which allows it to run long enough to remove moisture from the air. An air conditioning system that runs for a short period of time cools the air but doesn’t remove moisture, resulting in a cool but uncomfortable home.
Yes, the energy code requires that all heating/cooling system ductwork be sealed with duct mastic or approved tape. Regular duct tape is not approved. Up to 30 percent of heated or cooled air can escape from the ductwork through unsealed joints and gaps. It’s especially important to seal ductwork that passes through unheated garages or attics where the conditioned air is lost to the exterior.
Insulating basements and crawlspaces lowers energy bills and makes the home more comfortable. Concrete foundation walls provide little insulation value, less than R-2 (new windows are rated at R-3). In winter, the ground temperature three feet below the surface can be in the 30 degrees farenheit range. If the basement or crawlspace is kept around 65 degrees, significant heat loss occurs through these non-insulated concrete walls. Heat moves from hot to cold in all directions. The code requires insulating, but not finishing, a basement wall. Another option for crawlspaces is to insulate the floor and treat the crawlspace as unheated/unconditioned space. See pages 5 and 6 of the Residential Code Summary Booklet for crawlspace insulation options.
Crawlspace vents are no longer needed for heated/conditioned crawlspaces. In the past, vents were installed in a crawlspace to help remove moisture from the crawlspace. Most of the moisture was coming from the ground and evaporating into the crawlspace. The most common way of finishing a crawlspace is to insulate the foundation wall and install a ground cover (usually 6-mil black poly) sealed at the seams and sealed to the foundation wall. Note that the ground cover can also be part of a radon mitigation system. Temporary vents are allowed during construction of the house in case the crawlspace gets wet during construction, but when completed the vents should be insulated and sealed.
Neither the 2012 International Energy Conservation Code (IECC) nor 2012 International Residential Code (IRC) provide a clear answer.
The 2012 IECC Code and Commentary provides some direction with information on the definition of an exterior wall, “… an exterior wall is vertical or sloped at an angle of sixty degrees or greater from horizontal. This limitation may still be helpful to consider if dealing with unusual situations such as an A frame building.”
ASHRAE 90.1 2010 provides an exterior wall definition for Commercial buildings, “Wall: that portion of the building envelope, including opaque area and fenestration, that is vertical or tilted at an angle of 60 degrees from horizontal or greater. This includes above and below grade walls, between floor spandrels, peripheral edges of floors, and foundation walls.”
Note: The Building Code Official in the local jurisdiction would make the final decision on a code interpretation.