Energy efficiency renovations include measures such as adding insulation, caulking and weatherstripping, improving or replacing windows and doors, and upgrading the mechanical systems.
It is important to understand that a house operates as a system. Besides occupant activities and the external environment (e.g. temperature, wind, rain, air quality and noise) the elements of a house such as insulation levels, airtightness, window and door types, ventilation rates, heating and cooling systems all affect each other and this combination affects the overall house performance. For example, even if you are investing in new heating and cooling equipment or new windows and doors, you cannot optimize the energy performance of your house if you are not keeping heat in during the winter and out during summer.
Insulation upgrades coupled with air sealing are among the most cost-effective home retrofits. This simple home improvement sometimes pays for itself in less than a year and continues to payback for the life of the house. This upgrade may also reduce loads on heating and cooling equipment allowing for smaller and more efficient systems.