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How to choose the right insulation R-value

What is an R-value?  

An R-value is a rating which measures how well insulation can resist heat flow. ‘R’ stands for thermal resistance.

  • R-value level depends on a number of things such as the type of material, its density and thickness.
  • Higher R-value = Better insulation


Why is a higher R-value better?

Tiny air particles trapped in insulation resist the transfer of heat (and cold). The higher the R-value, the better the insulation is at reducing heat flow.  This means, for example, that Pink® Batts® Ultra® R4.0 insulation is more effective than Pink® Batts® Classic R1.8 insulation.

Pink® Batts® Classic is our lower R-value range of insulation, designed to achieve minimum building code requirements. For higher R-values go for our premium Pink® Batts® Ultra range. 

Different insulation products have different R-values. Some materials insulate better than others and others need increased thickness in order to reach the same R-value as a better insulating material. 


Common building material R-values*

*Sourced from Stonegreen, converted from imperial to metric 


Recommended minimum product R-values throughout New Zealand

Under the New Zealand Building Code (NZBC), new homes must be insulated to a minimum standard, depending on the area of the country in which you live.


NZBC R-Value product minimum standards 

(applicable to a timber-framed house*)
R-value zones New Zealand

 Zone 1 & 2: North Island, excluding the Central Plateau

Roof R3.2 Ceiling 
Walls R2.2 Wall
Floors R1.6 SnugFloor

 Zone 3: South Island and the North Island Central Plateau

Roof  R3.6 Ceiling
Walls  R2.4 Wall
Floors  R1.6 SnugFloor


*Typical Pink® Batts® R-value required to meet minimum NZBC clause H1 and may not comply with NZBC in all situations.

Find out about full construction R-Values required under the New Zealand building code


Have questions about insulation?