When discussing any kind of insulation, it’s important to understand R-values, or thermal resistance. Simply put, the R-value is a measure of the effectiveness of insulation: the larger the number, the better it is at trapping heat. An ordinary single-glazed aluminium window has an R-value of around 0.15, while the very best double-glazing achieves around 0.5. 

Ceiling insulation

The most critical part to insulate in your clubroom (and home) is the ceiling, as heat rises and easily escapes through an uninsulated roof. There is a wide range of insulating products available, each appropriate for different roof types and situations. While it is always best to speak with a professional before selecting a product, please ensure the insulation you pick meets the following criteria:

  • Its R-value, relating to the effectiveness of insulation, is at least 2.9 for North Island and 3.3 for South Island buildings - but if you can afford a higher R-value, always go for it.

  • It is designed for installation in ceilings.

  • It has the correct width to fit between the rafters or joists, to avoid gaps.

  • It complies with Standard AS/NZS 4859.1 (this will be printed on the packaging).

Be cautious about choosing ‘loose fill’ insulation, which is blown into cavities that can’t easily be reached. While it can be useful for inaccessible areas, it is difficult to ensure correct distribution of the material, making its insulating performance variable.

For more details on the different types of ceiling insulation to choose from check out these summaries by BRANZ and EECA.

Installing ceiling insulation

The key consideration when installing insulation at most clubs is the size of the ceiling cavity, or the space between ceiling and roof. ‘Attic’-type ceilings with easily accessible cavities can be insulated with minimal or no modification. In contrast, ‘skillion’ or ‘cathedral’ ceilings often have limited clearance between ceiling and roof. In such cases, the roof space may need to be modified or the ceiling lowered before insulation can be installed.

Before installing insulation, address any leaks, air gaps or wiring issues in the ceiling space. If the club is considering upgrading its interior lighting, this is a great time to replace any recessed down lights as well. Safety gaps must be left around these fittings for fire safety reasons, which reduces the performance of the insulation. If the club wishes to retain its down lighting, some modern LED downlights that are rated IC, IC-F or IC-4 can have compatible insulation fitted over them to keep the heat in, but make sure to check with an insulation professional or electrician beforehand.

While it is possible to install insulation yourself, it is recommended to hire a professional if you can: even small faults in installation can reduce the performance and durability of your insulation. Click here for a list of installers accredited by the Insulation Association of New Zealand. If you do choose to install insulation yourself, make sure you review the NZ Standard for installing ceiling insulation first. It is especially important to take note of the Health and Safety procedures located in Appendix B of the document.

Window insulation

Windows are a key source of heat loss, particularly, if all other parts of the building are well insulated.  There are four main options for reducing heat loss through your windows. They all work by creating a pocket of air between the exterior pane and the building’s interior. It’s this air pocket that provides the insulating effect, reducing heat transfer to the outside.

  • Film-based window insulating kits are reasonably effective, cheap to buy and simple to install yourself. However, they lack durability and longevity, and may not be aesthetically pleasing. Ensure your windows seal well and have no draughty gaps before you install the film - if the gap between the window and film is not airtight, its insulating value will be greatly reduced. This is a great short-term option if you are unsure if more expensive options like secondary or double-glazing are right for you.

  • Installing thermal curtains or honeycomb blinds. While they are not as effective as full double-glazing, their insulating performance is very good relative to their initial cost. They can also be combined with other window insulation options, maximising the benefits of both. To ensure warm air can’t infiltrate behind the curtains, close off the top by adding a pelmet or installing the curtain tracks inside the window frame. Make sure the curtains reach all the way to the floor or sill, and to the edges of the frame or further. Ideally, use two or more layers of fabric in the curtains to trap air in the curtain itself, increasing its insulative value.

  • Secondary glazing involves the installation of an additional pane to your existing windows. While slightly less effective than double-glazing, thermal resistance is still greatly increased compared to a single-glazed window, and it is approximately half the price of double-glazing to install. There are many kinds of secondary glazing available to suit your current windows. If funds are limited, prioritise south and west facing windows. When purchasing secondary or double-glazing, look out for low-E coatings or films. These coatings let the sun’s heat in but not out, trapping more heat.

  • Double-glazing consists of two panes of glass separated by air or an inert gas like argon. While expensive to install, certain types of double-glazing can achieve R-values over three times greater than a standard single-glazed aluminium-framed window. When considering double-glazing, it’s also important to think about framing materials. Some framing materials (like aluminium) conduct heat away from the interior more readily than others (like timber). Look for timber, or thermally-broken frames when purchasing. Even triple-glazing is available, further increasing their R-value.

Underfloor insulation


Good underfloor insulation can restrict ground moisture from entering a clubroom - making a big difference to how comfortable the space and how high your energy bill is. In clubrooms with accessible underfloor spaces, it’s relatively cheap and easy to do. EECA Energywise provide some great tips for both the options of DIY and getting in a professional to help.

Wall insulation

Once ceiling and underfloor of your building are insulated, the next logical step is to insulate the walls. The perfect time to do so is when renovations require removing the cladding or lining of your walls anyway. EECA Energywise have summarised what types of wall heatings there are to choose from and what to look out for when choosing your product. They also supply a guide on the how-to and what to look out for when installing wall insulation.