If you're renovating your home, the things you can't see - like warmth, comfort and dryness - are just as important as what it looks like. Do it once and do it right, and you'll enjoy the benefits well into the future.
- Draught stopping
- Double glazing
- Thermal mass
- Hot water
- Building code
Insulation is a fundamental part of making your home warmer, drier and healthier. Get your ceiling and underfloor insulation up to a good standard first. The next step is to insulate the walls. To do this, take the internal wall lining or external cladding off, install insulation and re-line the walls. It’s more cost-effective to do this while you’re renovating. If you have recessed downlights, consider replacing them with non-recessed light fittings, or modern downlight fittings that can be insulated over.
Older houses often leak a lot of air, which means heat can easily escape. Problem areas include unused chimneys, cracks between floor boards and badly-fitted windows and doors. A good start is to:
- close gaps
- block unused chimneys
- seal obvious holes and gaps with sealant and expanding foam
- put seal strips on doors and windows.
Fixing dampness, mould, mildew and musty smells are easy tasks when you’re renovating.
- Add extractor fans to wet, steamy areas of the home - such as kitchens, laundries and bathrooms.
- Don't vent into the ceiling space - it's bad for your house and your health, and it is not compliant with the Building Code.
- Check for rising damp under the house - ensure that vents are open and consider putting down a ground vapour barrier.
- Avoid unflued gas heaters - they release a lot of moisture.
Double glazing not only minimises heat-loss, it reduces condensation and acts as sound-proofing. Some double glazing is more effective than others - look for windows with frames that have insulating properties (for example wood, PVC or thermally-broken aluminium), low-emissivity (low-E) glass and an inert gas filling between the glass layers. There are also secondary double-glazing options that can work with your existing windows.
Once you have draughts, dampness and insulation under control, the next step is to think about space heating. There are several factors you need to consider, including the amount of heating you need, the running costs and the environmental impacts of the different options.
Thermal mass is a term used to describe solid materials that absorb heat in daylight and release it at night. If you have a house with windows that face north and rooms that get direct sunlight, adding or exposing existing thermal mass will make better use of free heat from the sun.
- If you have a concrete floor - consider exposing it (you can polish or paint it) where it gets direct sun. The concrete will absorb heat during the day and release it slowly at night.
- If you have wooden floors - thermal mass can be added by pouring 50mm or more of concrete on top of the wood. Check with a builder to see if your floors are suitable for this option.
Don't forget that any thermal mass needs to be exposed to work properly. That means not covering it with carpets, rugs or any other type of insulation.
The systems you use in your home can have a big impact on running costs. Many older houses have an outdated hot water system that you could consider replacing as part of your renovations, particularly it’s getting close to the end of its life.
Modern, efficient lights are available that not only save energy but also last a long time.
In New Zealand we have two different energy labels for products and appliances:
- Energy rating labels - give you information on how much energy a product uses and a star rating so you can compare similar models.
- ENERGY STAR® labels – displayed on products that meet an independent, international benchmark for superior energy efficiency.
All building work, including renovations, needs to comply with the Building Code. You can find more information on the Department of Building and Housing's website, or by contacting your local council.