Insulation for existing homeowners
Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.
To determine whether you should add insulation, you first need to find out how much insulation you already have in your home and where it is. Oz Homes Insulation’s qualified home energy assessor will include an insulation check as a routine part of a whole-house energy assessment. An energy assessment, also known as a home energy audit, will also help identify areas of your home that are in need of air sealing.
If you live in a newer house, you can probably get this information from the builder. If you live in an older house, you’ll have to inspect the insulation or simply give us a call.
How Insulation Works
To understand how insulation works it helps to understand heat flow, which involves three basic mechanisms — conduction, convection, and radiation. Conduction is the way heat moves through materials, such as when a spoon placed in a hot cup of coffee conducts heat through its handle to your hand. Convection is the way heat circulates through liquids and gases, and is why lighter, warmer air rises, and cooler, denser air sinks in your home. Radiant heat travels in a straight line and heats anything solid in its path that absorbs its energy.
Most common insulation materials work by slowing conductive heat flow and convective heat flow. Radiant barriers and reflective insulation systems work by reducing radiant heat gain. To be effective, the reflective surface must be in contact with an air space.
Regardless of the mechanism, heat flows from warmer to cooler areas until there is no longer a temperature difference. In your home, this means that in winter, heat flows directly from all heated living spaces to adjacent unheated roofs, garages, basements, and especially to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors–wherever there is a difference in temperature. During the cooling season, heat flows from the outdoors to the interior of a house.
To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.

Insulation materials run from bulky fiber materials such as fiberglass, rockwool, cellulose, and natural fibres to rigid foam boards to sleek foils. Bulky materials resist conductive heat flow in a building cavity. Rigid foam boards trap air or another gas in their cells to resist conductive heat flow. Highly reflective foils in radiant barriers and reflective insulation systems reflect radiant heat away from living spaces, making them particularly useful in cooling climates. Other less common materials such as cementitious and phenolic foams and perlite are also available.