Renovating

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.

Insulation

Insulation is the key to making your home warmer, drier and healthier. If you have accessible ceiling and subfloor spaces then ceiling and underfloor insulation can easily be installed at any time. Insulating walls and skillion roofs is best done during renovations. To do this, take the internal lining (or external cladding) off, install insulation and re-line the walls or skillion roof. If you have recessed downlights, consider replacing them with non-recessed light fittings, or modern LED downlight fittings (with an IC, IC-F or IC-4 rating) that can be insulated over.

 Insulation

Draught stopping

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:

  • block unused chimneys
  • seal obvious holes and gaps with sealant and expanding foam
  • put seal strips and draught excluders on doors and windows.

 Draught stopping

Dampness

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. Vent outside instead.
  • Check for rising damp under the house - ensure that vents are not blocked and consider putting down a ground vapour barrier.
  • Avoid unflued gas heaters - they release a lot of moisture and toxic fumes.

 Dampness

Double glazing

Double glazing reduces heat-loss and condensation and acts as sound-proofing. It is standard in new houses but it's also worth installing in existing homes, particularly if you’re doing substantial repairs or replacing the windows. If you need to prioritise, install double glazing to the main heated areas of the house as well as to large windows. 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) and low-emissivity (low-E) glass. There are also secondary double-glazing options that can work with your existing windows.

 Double glazing

Heating

Once you have draughts and insulation under control, the next step is to think about space heating. There are several factors you need to consider, including how much and how often you intend to heat the various rooms of your house, working out what size heater is needed for each room, the running costs and the environmental impacts of the different options.

 Heating

Hot water

When fitting a new showerhead or new tapware, check the Water Efficiency Labels to ensure you are choosing efficient products. The efficiency of your showerhead has a particularly big impact on water and water heating costs – choose one with a flow rate of 9 litres per minute or less.

If you have an electric hot water cylinder, check the thermostat is set to 60 °C and install a cylinder wrap and pipe lagging if space permits. If you’re replacing the hot water system, compare ongoing running costs, as well as the upfront purchase price with our water heating systems tool.

If you’re changing from low-pressure to mains-pressure hot water, make sure your new shower flow rate does not exceed 9 litres per minute. Either check the Water Efficiency Label of your new showerhead, or, if you keep your old one, do the bucket test: if your shower fills a 10 litre bucket in less than a minute (at normal showering temperature), it's wasting energy and water.

 Saving money on hot water

 Choosing a water heating system

 Water heating systems tool

Lighting

Modern, efficient LED and CFL lights save energy and last a long time. In addition, if you have recessed downlights, replacing them with modern LED downlight fittings (with an IC, IC-F or IC-4 rating) means they can be insulated over.

 Lighting

Appliances

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 selected products that meet an independent, international benchmark for superior energy efficiency.

 Appliances

 Energy rating labels

 ENERGY STAR

Building code and building consent

All building work, including renovations, needs to comply with the Building Code and may need a building consent. You can find more information on the Building Performance website, or by contacting your local council.

Building Consent - Building Performance website