Thermal performance and insulation testing

BRANZ provides full testing and consultancy services for thermal transmission, thermal resistance, thickness and density. This includes thermal imaging and computer-simulation modelling to support product development and specification decisions.
Last updated 18 May 2026
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Why test for thermal performance?

Testing the thermal performance of insulation and building materials helps deliver healthier, more energy-efficient buildings. 

Improved energy efficiency

Identify heat loss pathways and thermal resistance in real conditions. 

Greater specification confidence

Compare options and support product claims with independent data. 

Reduced risk

Test and refine products and details before they are repeated or scaled.

Better comfort

Identify cold spots, overheating, weak details and thermal bridging. 

Testing your products and systems

We test and analyse the performance of products and systems:

  • Insulation and thermal materials such as glazing, polyester, rigid foam, timber and wool.
  • Building elements such as walls, roofs and floors.
  • Junctions and details where thermal bridging is a risk.

Standards we meet for assurance and trust

We test to thermal performance standards, including:

  • ASTM C518 – steady-state thermal transmission by heat flow meter
  • AS/NZS 4859.1 – thermal insulation materials for buildings
  • ISO 8301/ISO 8302 – thermal resistance and conductivity methods.

We can also develop bespoke methods to inform your decisions. If you’re unsure what you need, we’ll guide you to the most appropriate pathway. 

Why trust BRANZ?

BRANZ has been testing insulation for over five decades. Our research has directly shaped the New Zealand Building Code requirements and standards for the thermal performance of building materials.

We bring expertise in building physics and thermal performance, with international experience across Australia, the UK, Malaysia, Thailand, China, Taiwan, the USA, South Korea and Singapore. We also test and analyse existing buildings to understand how they perform in use.

Our accreditations

BRANZ holds different accreditations covering the products and systems we test.  

Through the International Laboratory Accreditation Cooperation mutual recognition agreement, BRANZ-accredited test reports are recognised as the equivalent of those issued by laboratories accredited by 68 bodies around the world.

BRANZ has achieved and operates a management system conforming to AS/NZS ISO 9001.

Unsure what you need to test for?

Additional methods are available on request. If you’re unsure what you need to test to, we’ll guide you to the most appropriate method based on your product, intended use and audience for the results.

Get in touch with us to have a chat.  

Get started with testing

Tell us what you’re aiming to achieve, your timeframe, and what you need tested and we’ll guide you through the rest.
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