R-Values - what are they?
What is an R-value and how can I increase it?
Effective insulation is extremely important when it comes to the energy efficiency of your home. R-values help us to ensure you have sufficient insulation for your area.
R-value tells us how well the chosen insulation resists heat flow. If can differ subject to the thickness, direction of heat flow and the make up of the insulation. The higher the R-value, the better the performance of your insulation.
R-values vs. U-values?
U-value measures the conductivity. Generally has a rating from 0.1 (very little heat loss) to 1.0 (high heat loss). The lower the U-value the higher the performance.
Both values are considered when it comes to calculating the energy efficiency in a home, U-value is often used in glass units whereas R-value applies to most insulations.
How are R-values calculated?
This is usually done with thermal modelling software in line with the current standards. U-values, area of the materials, frame etc are all taken into account and the value is calculated as a combined total.
When we are putting together your quote, we will ensure the requirements are met based on the current requirements in your area.
New Insulation Standards
The current requirements for windows on new builds is for them to be double glazed and have an R-value of 0.26. This will no longer be sufficient and will be increased to 0.37 for stages 1 & 2 (03NOV22, 01MAY23), with the final stage seeing this increase to 0.46 (02NOV23).
If you haven’t already, be sure to have a read of our blog on the upcoming changes to the NZ Building Code.
What R-value do I need?
Requirements differ for certain components of your build – walls, floors, ceiling, roof. We can’t comment on other areas of your build but can give you what you need for your windows and doors.
Windows/Doors – Joinery Current standards (until 02NOV22) have our area at an R-value of 0.26 for new build houses. This can be achieved with standard aluminium joinery paired with plain double glazing.
Standard will increase for different areas in steps over the next 12 months. You will need to meet higher criteria to ensure the overall efficiency of your new home. This can be achieved through thermally broken frames, low-e glass and gas filled units.
Please note that as we are located in Zone 1 (Auckland) all dates, standards and details are relating to our area only.