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How to Stop Designing Mouldy Buildings€¦ · How to Stop Designing Mouldy Buildings (and...
Transcript of How to Stop Designing Mouldy Buildings€¦ · How to Stop Designing Mouldy Buildings (and...
How to Stop Designing Mouldy Buildings (and mainstream the thermal bridge)
Simon McGuinness, MRIAI
TGD - D.2 Mould growth & surface
condensation
The key factor used in assessing
the risk of mould growth or
surface condensation in the
vicinity of thermal bridges is the
temperature factor (fRsi).
For dwellings, the value of fRsi
should be greater than or equal
to 0.75, so as to avoid the risk
of mould growth and surface
condensation.
TGD - D.2 Mould growth & surface
condensation
The key factor used in assessing
the risk of mould growth or
surface condensation in the
vicinity of thermal bridges is the
temperature factor (fRsi).
For dwellings, the value of fRsi
should be greater than or equal
to 0.75, so as to avoid the risk
of mould growth and surface
condensation.
For fRsi > 0.75
Tsi > 15degC
TGD - D.4 Calculation procedures
The calculation procedure to
establish temperature factor
(fRsi) is outlined in BRE IP 1/06.
Details should be assessed in
accordance with the methods
described in I.S. EN ISO:10211.
Which in turn references I.S. EN
ISO:13788 as “indispensable for
the application of this
document.”
TGD - D.4 Calculation procedures
The calculation procedure to
establish temperature factor
(fRsi) is outlined in BRE IP 1/06.
Details should be assessed in
accordance with the methods
described in I.S. EN ISO:10211.
Which in turn references I.S.
hEN ISO:13788 as “indispensable
for the application of this
document.”
ISO hEN 13788: 2012 (December 2013)
Walls, Floors, Ceilings
fRsi calculation
0.25 m2K/W surface resistance
0.25 m2K/W surface resistance
0.25 m2K/W surface resistance
ISO hEN 13788: 2012 (December 2013)
0.10 ^
0.13 >
0.25 ^
0.25 >
ISO hEN 13788: 2012 (December 2013)
0.10 ^
0.13 >
0.25 ^
0.25 >
Gable/Eaves cavity wall example
ACD 1.09 ACD 1.15
Gable/Eaves cavity wall example
ACD 1.09 (Eaves) and
ACD 1.15 (Gable)
Under construction
In Dublin in 2015
Gable/Eaves cavity wall 3D model
3-D Thermal Modelling – Fails fRsi
Add 2.5 thermal blocks & mineral wool
Thermal Modelling – barely passes fRsi
What does the responsible educator do?
Double-checked the standards
Revised the syllabus
Warned previous Thermal Modeller graduates
Advised the regulators
Advised the RIAI
Issued three blog postings on BRegsForum
Tweeted on social media
Asked for clarification from the Minister
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Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
“I refer to the reply to Question
No. 788 of 15 April 2015 which
addressed the approach to
calculating the temperature factor
in the vicinity of thermal bridges at
junctions and around openings in
accordance with Appendix D of
Technical Guidance Document L
2011. ….”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
“I refer to the reply to Question
No. 788 of 15 April 2015 which
addressed the approach to
calculating the temperature factor
in the vicinity of thermal bridges at
junctions and around openings in
accordance with Appendix D of
Technical Guidance Document L
2011. ….”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
”… A surface resistance value of
0.25 is only used in very specific
situations as outlined in section 4.4
of the EN ISO 13788 standard
which is of rather limited relevance
in this context and, for that reason,
it has not been referenced at
Appendix D of TGD L 2011 or
referred to in the reply to
Question No. 788 of 15 April
2015.”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
“I refer to the reply to Question
No. 788 of 15 April 2015 which
addressed the approach to
calculating the temperature factor
in the vicinity of thermal bridges at
junctions and around openings in
accordance with Appendix D of
Technical Guidance Document L
2011. ….”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
”… A surface resistance value of
0.25 is only used in very specific
situations as outlined in section 4.4
of the EN ISO 13788 standard
which is of rather limited relevance
in this context and, for that reason,
it has not been referenced at
Appendix D of TGD L 2011 or
referred to in the reply to
Question No. 788 of 15 April
2015.”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
“I refer to the reply to Question
No. 788 of 15 April 2015 which
addressed the approach to
calculating the temperature factor
in the vicinity of thermal bridges at
junctions and around openings in
accordance with Appendix D of
Technical Guidance Document L
2011. ….”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
”… A surface resistance value of
0.25 is only used in very specific
situations as outlined in section 4.4
of the EN ISO 13788 standard
which is of rather limited relevance
in this context and, for that reason,
it has not been referenced at
Appendix D of TGD L 2011 or
referred to in the reply to
Question No. 788 of 15 April
2015.”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
“I refer to the reply to Question
No. 788 of 15 April 2015 which
addressed the approach to
calculating the temperature factor
in the vicinity of thermal bridges at
junctions and around openings in
accordance with Appendix D of
Technical Guidance Document L
2011. ….”
Minister of State for the
Environment, Community and
Local Government (Deputy Paudie
Coffey)
”… A surface resistance value of
0.25 is only used in very specific
situations as outlined in section 4.4
of the EN ISO 13788 standard
which is of rather limited relevance
in this context and, for that reason,
it has not been referenced at
Appendix D of TGD L 2011 or
referred to in the reply to
Question No. 788 of 15 April
2015.”
?
Can the Design Certifier Rely on
the ACDs to deliver a Mould-free
Compliant Design?
On the basis of our work in the last
12 months, it is significantly less
than “certain” that he or she can.
Can the Design Certifier Rely on
the ACDs to deliver a Mould-free
Compliant Design?
On the basis of our work in the last
12 months, it is significantly less
than “certain” that he or she can.
How did it impact on the DIT nZEB Retrofit
Project 2015?
Current BER: 363 kWh/m2a
Target: 45 kWh/m2a
Saving Per Unit: 318 kWh/m2a
Cabra alone: 3,800 similar houses
Total Savings: 1,208, 400 kWh/m2a
Money Saved: €9million per year
Would fund 200 retrofits per year
In 19 years it would be complete
How did it impact on the DIT nZEB Retrofit
Project 2015?
Current BER: 363 kWh/m2a
Target: 45 kWh/m2a
Saving Per Unit: 318 kWh/m2a
Cabra alone: 3,800 similar houses
Total Savings: 1,208, 400 kWh/m2a
Money Saved: €9million per year
Would fund 200 retrofits per year
In 19 years it would be complete
Thermal Modelling used to check for fRsi
Thermal Modelling used to check for fRsi
Thermal Modelling used to check for fRsi
How to reduce the cost of retrofit …
€560 per ACD x 178 ACDs x 2 U-values = €100,000
Would take 3 months and employ 5 researchers, or
€10,332 cost per home x 1.3 Million homes = €13,431,600,000
How to reduce the cost of retrofit …
€560 per ACD x 178 ACDs x 2 U-values = €100,000
Would take 3 months and employ 5 researchers, or
€10,332 cost per home x 1.3 Million homes = €13,431,600,000
One of these
is “cost
optimal”
The Dublin School of Architecture and
Building looks forward to working with
Government and the construction industry to
resolve all the technical issues necessary to
achieve nZEB Retrofit safely, cost effectively
and speedily. By working together, we are
confident we can achieve our national targets.