How Will I Know If My Home Needs More Insulation?
- The difference between an un-insulated and under-insulated home
- Why is underfloor insulation important?
- Do you still have questions?
» Signs of a cold home
If you are experiencing any of the things listed below (especially during winter), you might be living in an un-insulated, or under-insulated home.
- high power bills for the number of occupants in the home (although lack of insulation is not necessarily the cause of high power bills).
- very low fuel bills (e.g. for electricity, wood, or gas etc) despite cold weather. You may have given up heating your home because you find it is too expensive to heat properly.
- a heater switched on, but isn't heating the room properly. This may also mean your house has good insulation, but your heater isn't sized correctly for the room.
- the surface of the floor may feel very cold
- problems with dampness and condensation
- mould in cupboards and on walls
- problems with colds and flus, especially during the cooler months of the year.
» The difference between an un-insulated and under-insulated home
Your home is un-insulated if there is no ceiling, floor or wall insulation whatsoever. Photo (1) below shows an uninsulated ceiling space with one biscuit of ceiling insulation installed between the rafters.
Photo (2) shows an example of a house on suspended timber foundations which has not had the underfloor insulated. Only houses built on these kinds of foundations can be retrofitted with underfloor insulation. They tend to be built during or before the 1970's. Houses built during or after the 1970's are more commonly built on concrete slabs and cannot be retrofitted with underfloor insulation.
(1) (2)
Your house is under-insulated if you have insulation but it does not meet the current building code-standards. As of October 2008 the required R-Values in Canterbury are:
Source: Department of Building and Housing (2007) Your guide to $marter insulation. pp 10
An under-insulated house will be cold and expensive to heat. A house can be under-insulated for a number of reasons.
- Ceiling insulation will settle and thin over a period of 15-20 years, significantly reducing its thermal resistance and effectiveness.
- Sometimes a house didn't get a sufficient amount of insulation when it was first installed.
- The house was insulated prior to changes to existing Building Code Standards.
Signs of an under-insulated ceiling or roof space include
- uneven coverage, with existing insulation piled up in the corners and thin in other places
- exposed rafters and ceiling infrastructure in the roof space
- if the level of insulation is lower than the height of your rafters (joists).
See photos 1 and 2 below for examples of insulation in an under-insulated roof-space.
(1) (2) (3)
Another tell-tale sign inside the living spaces of a home is if you have dirty lines forming on your ceiling (photo 3). This happens when the warm air in your room rises and is able to escape through the ceiling lining because it is not insulated. This air escapes and leaves fine dust particles on your ceiling. The lines are the ceiling joists which provide a bit more insulation than your ceiling lining - the warm air doesn't escape through the joists. In photo 3 above, the left side of the ceiling has insulation, but the right side has no insulation.
CEA estimates there are a lot more under-insulated ceilings in Canterbury than un-insulated ceilings. This problem is easily fixed. CEA can top up your existing ceiling insulation with another layer of insulation to bring it up to existing Building Code Standards.
If your house is aged 15 years and over, it is very important to have your ceiling and underfloor insulation checked. CEA can do this for you at no cost and provide a free, no obligation quote if you need more insulation. We can also provide financial assistance to help pay for the cost if certain criteria are met. Call 03 374 5698, or email info@cea.co.nz to make a booking.
Please note: some kinds of ceilings cannot be insulated because of the design of the building. These include ceilings with a very low pitched roof, skillion roofs, and cathedral ceilings.
Due to cost and government funding criteria, CEA does not provide wall-insulation services.
» Why is underfloor insulation important?
Between 12-14% of heat is lost through the floor, compared to 30-35% through the ceiling (2). This is why, in terms of energy efficiency it is important to insulate the ceiling first.
But insulating underneath a house can have a significant impact on your comfort levels. This is because you live on the floor, not the ceiling! You will feel cold when you are contact with a cold floor surface and you need to maximise the warmth as close to your body as possible (including your feet). Underfloor insulation helps to do this.
Comfort underfoot is especially important for
- people with poor circulation or who spend a lot of time sitting
- for children and babies who live closer to the floor.
Insulating under a house which has very damp ground underneath does have clear energy-efficiency benefits as well. Moisture from this damp ground will circulate up through the floor boards into the house and it takes more energy to heat the resulting damp. This house will feel colder than a house with no dampness issues. Reducing dampness and condensation will help to reduce your fuel bill.
(2) Source: Department of Building and Housing (2007) Your guide to $smarter insulation. pp3
Do you still have questions?
The Home Energy Advice Centre provides free, impartial expert advice on home energy issues over the phone. The Home Energy Advice Centre is open Monday to Friday 10am to 4pm. They can be contacted on 0800 388 588.