About the Handbook and How to Use It

Assistance for industry to improve the thermal performance of buildings using the right insulation

The new industry 'Insulation Handbook Part 1 Thermal Performance' provides the Total R-value calculations for typical building applications to assist designers, specifiers and builder to:

The handbook can be downloaded in a printable PDF format by clicking the following link Insulation Handbook. 

Four sections with diagrams are being created in HTML format on this site as a ready reference for your convenience. Two sections currently available are highlighted below:

1. About the Insulation Referenced in the Handbook

2. Roof Insulation Calculations

3. Wall Insulation CalculationsFlat Concrete Roof with Suspended Ceiling Plenum Return

4. Floor Insulation Calculations

We recommend you review section 1 'About the Handbook and its Contents' before proceeding to the calculation sections. Also note that when using the handbook, while some applications can be used to achieve “Deem to Satisfy” solutions for the BCA Energy Efficiency Provisions, not all solutions will achieve compliance for all applications.

Total R-Value

R value means the thermal resistance (m2K/W) of a material calculated by dividing the thickness by its thermal conductivity.

Total R-Values are based on the sum of all components of the building system including indoor and outdoor air-films, building materials used in the system and air-spaces.

  1. Bulk insulation thermal resistance is expressed by Material R-Value
  2. Reflective insulation thermal resistance is expressed in terms of Total R-Value

Calculations in this handbook have been made using practical assumptions for typical situations, and using conservative assumptions expected in actual systems (rather than ideal theoretical systems that are unrealistic to achieve in practice). In particular the effect of anti-glare coatings or dust on the top surface of foil has been taken into account in accordance with the 2006 amendment to AS/NZS 4859.1.

In addition to the Total R-Value of the structure, the un-insulated R-Values are also provided to demonstrate the thermal resistance without reflective foil: these are shown for summer and winter conditions.

Added R-Values indicate the improvement in thermal resistance achieved by correct installation of insulation products. In the case of reflective insulation, these details may be used in combination with other complimentary insulation products to satisfy BCA requirements for added insulation.

Note that the correct choice of insulation is dependent on a range of factors, other than thermal performance. Other factors may include condensation control, moisture absorption, non-combustibility and acoustic performance.

Recommendations made in this handbook are based on Australian climate conditions

BCA Climate Zones

How to use this handbook

Determine which climate zone your project is located in Australia from the map.

Note: Building classes are defined by the BCA and are summarised on the following page

NOTE: Some applications may achieve Total R-values sufficient to comply with the minimum performance levels of the Deemed to Satisfy requirements contained in the Energy Efficiency Provision of the BCA.

BCA Classesof Buildings

GLOSSARY OF TERMS

Added R-value  Thermal resistance added to a construction element by insulation
 Bulk insulation Insulation depending for its performance upon thickness and thermal conductivity to achieve Material R-value
 Climate Zone   An area defined in the BCA Climate Zone Map of Australia having energy efficiency provisions based on a range of similar climate characteristics
Conduction Heat flow transfer by exciting molecules of a solid material
Convection Heat flow transferred by movement of a fluid (eg. air movement)
Double Sided Reflective foil on both faces of reflective insulation
Double Sided Antiglare Reflective foil on both faces of reflective insulation with additional ink coating on external face (for OH&S antiglare requirements)
Emittance  Ratio of radiant energy emitted by a surface compared to that of a blackbody (a blackbody emits radiant energy at the maximum rate possible)
FBS-1 Glass Wool Insulation composed of bio-soluble glass fibres
 
FBS-1 Mineral Wool       Insulation composed of fibres manufactured from glass or rock
FBS-1 Rock Wool Insulation composed of bio-soluble rock fibres
Heat Transfer Heat flow from a hot to a cold body (see convection, conduction and radiation)
Indoor air film A layer of air adjacent to the internal surface of the building element
Material R-value Thermal resistance determined by dividing thickness by thermal conductivity, excluding surface air film resistances. NOTE: Material R-values shown in the applications may be higher or lower than that stated on packaging. Labelled Material R-values are determined in accordance with AS/NZS 4859.1 - Amdt. 1-2006. The contribution of any insulation product may vary due to the composition of the application. It is for this reason that the Material R-values may vary from their normal values.
Natural Ventilation An air space bounded by one or more permeable surfaces allowing a degree of air movement (eg. an attic space below an unsarked tiled roof)
Non-Ventilated Air space enclosed by non permeable building materials
Outdoor air film A layer of air adjacent to the external surface of the building element 
Radiation Heat flow transfer by electromagnetic radiation (infra red waves)
Reflective Attic Space Air space between flat ceiling and pitched roof bounded by reflective insulation under roofing material
 
Reflective Insulation Insulation depending for its performance upon reduction of radiant heat transfer across air spaces by use of one or more surfaces of high reflectance and low emittance 
Single Sided Reflective foil on only one face of reflective insulation 
Summer   Denotes BCA design heat flow direction INTO the structure 
System R-value  Thermal resistance of a system, or construction of different materials, excluding surface air film resistances 
Thermal conductivity   A measure of the ability of a material to conduct heat 
Total R-value  Thermal resistance associated with a material or system, including surface air film resistances
 
Ventilated   Air space ventilation provided by an opening designed to allow air movement, or by mechanical means 
Winter   Denotes BCA design heat flow direction OUT of the structure  

Disclaimer: The document has been compiled as an aid only and the information or advice should be verified before it is put to use by any person. The user should also establish the applicability of the information or advice in relation to any specific circumstances. While the information or advice is believed to be correct, ICANZ, its officers, employees and agents, disclaims responsibility for any inaccuracies contained within the document including those due to any negligence in the preparation and publication of the said document.