A European Multi-Criteria Evaluation and
Comparison of Insulation Materials
Stephen Long
September 23rd 2013
Global Insulation Conference, Aachen
Contents of the presentation
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Background
Objectives
Scope
Methodology
Key conclusions
Comparative results by application and country
Results by type of material
Summary
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Background
• Legislation is directed towards the building envelope in terms of
assessment of properties and this should be the usual practice.
• However, many previous studies have indicated differences in
insulation materials and statements continue to be made comparing
plastic insulation, mineral insulation and renewable insulation
materials.
• This study attempts to give a more thorough, objective basis for such
comparisons.
• PlasticsEurope contacted the Büro für Umweltchemie in Zurich to
carry out this new study
Objectives and use of the study
• The purpose of the study was to develop a multi-criteria evaluation
and comparison of different thermal insulation materials in Europe
• The result is an assessment of the contribution to sustainability, as
well as a guide to the advantages and weaknesses of these materials
used in buildings
• The study makes a contribution to the ongoing discussion about how
to take into account the sustainability-related performance of products
• The report should be seen as an opportunity to stimulate thoughts and
as an invitation for stakeholders to add their contributions in order to
progress further
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Scope
• Comparative assessment of the most important insulation materials in
their building applications using Germany, Italy and Sweden as
reference countries
• No results for Sweden however due to difficulties in obtaining reliable
information on specific applications and materials used
• Covers all typical insulation applications, and the most common
insulation materials used for these applications
• More than 300 insulation products analysed:
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Evaluated products/applications
Material
Germany
Italy
Sweden
Total
Stone wool
33
17
10
61
Glass wool
25
16
15
54
EPS Standard
44
17
21
82
Grey EPS
9
12
1
21
XPS
12
18
18
33
PUR/PIR
24
13
5
40
Foam glass
4
4
4
Natural fibres
11
3
1
16
Aerogel materials
3
2
2
4
164
98
77
316
Total
in flat roof, pitched roof, ventilated facade, ETICS and perimeter applications
Methodology (1)
• The comparison is made on products having the same insulation
performance:
It is methodologically essential to compare insulation materials taking
the final application in the building into account. This is achieved by an
assessment on the basis of the same performance (U-value) for a
given application, including all necessary measures to fix and protect
the material. This approach should be a prerequisite for all
comparative sustainability considerations of insulation materials and is
now also required by the European standardization of sustainable
construction assessments meanwhile developed in CEN TC 350.
Results can be different compared to a mass or volume based
approach.
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Methodology (2) - LCA
• An important part of the findings are based on data from Environment
Product Declarations according to ISO 14025
• Although these EPDs are based on the same standard and are
third party verified, comparability might be limited because of
different units taken into account and other methodological
differences
• More harmonized approaches will be needed in the future
• Data from Eco-Invent used in the absence of EPD
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Methodology (3) – hazard versus risk
• The most important additives with hazard classifications commonly used
in insulation materials discussed in general
• Simplified risk assessment undertaken, based on physical properties and
eco-toxicological parameters
• Due to lack of consistent exposure data, assumptions made on exposure
probabilities
• Methodology described in Saling/Landsiedel 2005
• Information on intrinsic hazards connected with projections on exposure
based on
• production volume,
• wide use of a substance in many applications
• possible exposure routes
• It is assumed that these indicators allow for a projection of exposure
probabilities with sufficient exactness, while it is not claimed that these
assumptions create an accurate picture of reality
• This aspect clearly requires further methodology developments to take
exposure into account more accurately
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Representation of the results
• Spider diagrams used to represent the criteria in a consistent,
graphical way
• The selection of the criteria (axes) represents the whole life cycle
including all aspects that are important according to common practice
and standards
• The axes indicate the extreme values for a given application.
Therefore it is not possible to compare insulation materials from one
application to another.
• The larger the number, the better the property, i.e. the larger the
shaded enclosed area in a spider diagram, the “better” the overall
assessment
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Spider diagram
Coverage of the life cycle stages
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Explanation of axes’ criteria
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Key conclusions
1.
2.
3.
4.
All insulation materials, including the impact of necessary
constructions and adaptations of the building, have an overall
positive effect on the sustainability of a building calculated over its
lifecycle
There is no single material that is best in all applications. Results
depends significantly on the application and construction
The performance of natural based materials is not necessarily better
than plastics or minerals
The climate region has only a minor effect on the results
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The results
• The most common applications and materials on the market today
have been assessed for Germany and Italy. Hence certain
applications or materials such as spray foam or sandwich panels that
might be more relevant in other countries are not covered in this
study.
• For Germany, five main insulation applications on roofs and walls
have been identified.
• In Italy two wall and two roof applications have been selected.
• One spider diagram presents the results for one insulation material in
a given application area.
• The graphic presentation of the results includes more than fifty spiders
in nine application areas.
Comparative results for flat roofs
Germany
Italy
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Comparative results for pitched roofs
Germany
Italy
17
Comparative results for ventilated façade
Germany
Italy
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Comparative results for ETICS
Germany
Italy
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Comparative results for perimeter
(Germany only)
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Results by type of material (1)
• General statements based on this comparative study are not possible
• Products of the same insulation material in different applications
can be very different in terms of density and thermal conductivity
• In consequence the results for one given material vary from one
application to another
• The spider concept does not allow comparisons between
different applications since the scales of axes are different
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Results by type of material (2)
• Mineral fibre products
• Glass wool has in general more advantages than stone wool.
Glass wool is best in most of the production aspects with the
application of ventilated façades and pitched roof (between
rafters)
• Currently produced mineral fibres have no hazardous potential
except for dust, but adequate workers’ protection can deal with
the related exposure risk. However there is hardly any recovery
potential with mineral fibres
• Foam glass
• Two common applications of foam glass are compact flat roof
and slabs fixed to the perimeter wall. There is no potential risk of
exposure to hazardous substances. Its summer smog potential is
the lowest in both applications. All other indicators were worse
compared to the alternatives.
Results by type of material (3)
• EPS is strong with three production LCIA indicators in the applications
flat roof, ETICS and perimeter
• Investment costs lowest within these applications. The grey type is
always more favourable than white EPS. The production LCIA
indicator for the photochemical ozone creation potential (POCP) is
normally worse in comparison to other materials; the reason is the
use of pentane as a blowing agent that contributes to ground-level
ozone creation when released from the foams.
• XPS has been proposed for perimeter, flat and pitched roof (over rafters)
applications
• Environmental performance is similar to EPS but with differences
derived from different surface weights and a lower summer smog
potential (POCP)
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Results by type of material (4)
• PUR/PIR is always best in terms of thickness per functional unit.
• In the flat roof and ETICS application the aspects of sustainability
are comparable to EPS standard
• A much lower recovery potential is accompanied by lower
summer smog potential
• Its potential risk is the lowest among plastic foams and
comparable to mineral materials.
Results by type of material (5)
• Natural fibre products have been analysed for the ventilated façade
(hemp fibre in Germany, flax fibre in Italy) and ETICS (wood fibre in
Germany) applications
• The advantages of natural fibres are enhanced recovery potential
and low potential risk
• The main disadvantage is a usually higher lambda value with
relatively high densities
• Hemp and flax fibre slabs in the ventilated façade have advantages
in climate friendliness, application suitability and the low potential
risk
• Wood fibre slabs in the ETICS application have high densities. Their
LCIA indicators for production are worse than plastic foam solutions.
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High level summary
• Plastic foams show superior performance in flat roof, pitched roof over
rafters and ETICS
• Density and thermal conductivity are usually lower for plastics foams
compared to mineral fibres. The higher tensile strength and the lower
water absorption of plastic foams are an advantage for many
applications.
• Natural fibre products do not necessarily have better performance
than other insulation materials.
• Glass wool has in general more advantages than stone wool.
• Mineral fibres are favourable regarding their reaction to fire without
any flame retardants and their negligible thermal expansion
properties.
Other comments
• A proper construction is a basic prerequisite for a long use period
without damage. It means appropriate fixing of the insulation, an
efficient protection from the influence of weather, sufficient tensile
strength for the related loads and measures to avoid condensed water
and thermal bridges.
• LCIA data from ecoinvent, Ökobau.dat and the available EPD’s vary
significantly.
• Continuing need to improve risk assessment methodology
• Inclusion of gate to grave assessments and associated methodology