Posted on 13 04 2022

What’s involved in insulating your home

House insulation is the single most effective measure you can take to keep your home comfortable all year round and to save money on energy bills.

If you’re building a new home, the best way you can protect its future, and the health of your family, is to ensure it’s insulated with the highest-grade product you can afford.

If you have the budget, you should consider insulating all the internal walls, as well as the garage, in case you ever want to use it as another bedroom or living area. At a minimum, a well-insulated home makes it more energy-efficient, comfortable, and dry.

Cold, damp houses

Shockingly, most New Zealand homes are poorly insulated, and a quarter of Kiwi families have no house insulation. This means our homes (particularly those built before 1978) are often cold, damp, and expensive to heat and cool.

If your energy bills are high and you're still experiencing dampness, it could mean your house insulation is below standard.

These homes often don’t get as warm inside as the recommended 18°C, which is a problem because, according to the World Health Organisation, indoor temperatures below 16°C increase the risk of respiratory disease.

Many homeowners try to fix this by installing heat pumps, dehumidifiers and other ‘band aids’ instead of addressing the fundamental problem – little or no insulation.

Insulate the ceiling first

A poorly insulated ceiling can result in 25% of your home’s heat escaping through the roof. This makes insulating your ceiling the critical first step in creating a drier, healthier and more energy-efficient home. 

We can arrange for one of our assessors to look at your home and discuss your needs, as well as product options, areas to be insulated, installation methods and warranties. An assessment typically takes about 40 minutes and gives us the information we need to recommend the most suitable and affordable option to suit your ceiling cavity:

  • Segments – rectangular sheets of insulation that are installed between the ceiling joists
  • Blanket – larger sheets of insulation that are installed over the ceiling joists
  • Loose-fill – This insulation is blown into a ceiling cavity using a specialised machine. We only recommend this option for very difficult to access ceiling cavities

Underfloor insulation

Underfloor insulation is one of the cheapest and easiest ways to improve your home health and comfort. Correctly installed, it will not only reduce heat loss through the floor, it can also help prevent moisture from penetrating into the house from a damp floor.

Underfloor insulation has the added benefit of reducing sound on wooden floors and helps eliminate draughts from exposed floorboards. 

There are two main options for underfloor insulation, and GreenSide Energy Solutions will help you choose the right one for your home:

  • Bulk insulation - Typically made from polyester, natural wool, rock wool, or expandable polystyrene material, this insulation traps heat inside the house during the winter and blocks heat from entering during the summer.  
  • Reflective foil insulation – Comes as either single or double-sided foil laminate, bubble wrap, or foam foil-faced wrap, designed to lower radiant heat gain. 

Wall insulation

Installing wall insulation will stop a significant amount of heat loss from your home and is obviously easier to do during a new build or renovation. However, the exterior walls of existing homes can be retrofitted with insulating foam, which is injected between each set of studs using a specialised machine. 

In most cases, your insulation work should be completed in a day, with minimal disruption for you. 

As an owner-occupier, you may also be eligible for a Warmer Kiwi Homes subsidy of 80% of your insulation cost. Get in touch with the Greenside team to find out if you meet the criteria and take the first step towards a warmer, healthier home.


As an Owner-Occupier You May Be Eligible for a Warmer Kiwi Homes Subsidy