The Future Envelope 12 Interreg IT-AU FACEcamp project ------------ Conference on Building Envelopes 20-21 May 2019, NOI Techpark, Bolzano (Italy) "It’s all about performances".

1. The Future Envelope 12
It’s all about performances
Addressing uncertainties in monitoring and
simulating enhanced fabric performance
Dr Christina Hopfe
Loughborough University
www.interreg.net
FACEcamp final event | Bolzano, 20-21 May 2019
FACEcamp is funded by European Regional Development Fund and Interreg V-A Italy-Austria 2014-2020.

2. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Problems
• Buildings underperform
• Performance gap not well understood
• How to separate losers from winners?
Source CIOB http://www.constructionmanagermagazine.com

3. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 1: Simulation engine - how accurate is it?
Mantesi, E., Hopfe, C. J, Cook, M. J., Glass, J. (2016). Investigating the impact of modelling uncertainty on the simulation of ICF for buildings. Proceedings from BSO2016
Conference. Newcastle, 12-14 September 2016, UK
Step 1: Inter-Model Comparison
Default Algorithms
Step 2: Parametric Analysis on
Equivalent Models
 Significant inconsistencies in the
simulation predictions provided
by 9 BPS tools ~ 57% difference.
0
1000
2000
3000
4000
5000
Annual Heating (kWh)
Tool E Tool I
0
0.5
1
1.5
2
2.5
A B C D E F G H I
Annual Heating (MWh)
57%
 Key factors affecting simulation results:
o Internal surface convection
coefficient
o Infiltration
o Variable natural ventilation
o Thermal bridging calculation

4. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 2: The modelling gap : what do we model?
Mantesi, E., Hopfe, C. J, Goodier, C., Glass, J., Cook, M. J. , Strachan, P. (2018). The modelling gap: Quantifying the discrepancy in the
representation of thermal mass in building simulation

5. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 3: the impact of the occupants
South- West view of Twiga Lodge, Surrey, UK

6. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 3: The impact of input and occupancy
Step 1: Uncalibrated Models
Input data from NCM
Step 2: Calibrated Models
Unoccupied Week
Step 3: Calibrated Models
Occupied Week
 Good agreement in the simulation
predictions provided by the two BPS
tools.
 Significant divergence between
simulation and monitoring results
when models uncalibrated.
 Overall good consistency between
simulation predictions from both BPS
tools and between simulation and
monitoring.
 The house is unoccupied – Scenario
uncertainty excluded from the analysis.
 Higher inconsistency in the simulation
results provided by the BPS tools.
 The divergence between simulation and
monitoring results is also higher in the
occupied period.
0
10
20
30
40
7/7 7/9 7/11 7/13
Internal Air Temperature Co
Living Room
Tool I Monitored Temp
Tool E Outdoor Temp
0
10
20
30
40
7/24 7/26 7/28 7/30
Internal Air Temperature Co
Living Room
Tool I Monitored Temp
Tool E Outdoor Temp
0
10
20
30
40
7/24 7/26 7/28 7/30
Internal Air Temperature Co
Living Room
Tool I Tool E
Outdoor Temp Monitored Temp
Mourkos, K., Mantesi, E., Hopfe, C. J, Goodier, C., Glass, J., Cook, M. J. (2017). The Role of Fabric Performance in the Seasonal Overheating of Dwellings. Building Simulation
2017.

7. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 4: the challenge of new materials
Mantesi, E., Hopfe, C. J, Glass, J., Cook, M. J. (2019). Empirical and Computational Evidence for Thermal Mass Assessment: The Example of Insulating Concrete Formwork,
Energy and Buildings, 188, 314-332

8. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 5: new challenges because of climate data sets..
• Wind driven rain (WDR) is a combination of wind and rain
• Different theories on co-occurrence wind and rain
• Large variability in geographic location
• WDR difficult to measure directly (incl. direction)
• Limited information of the influence of climate change
References: Tersteeg, Hopfe, Allinson, 2018. : Hygrothermal assessment of two solid-brick walls under varying internal and external parameter settings, Building
Simulation and Optimization (BSO)18, Cambridge

9. The Future Envelope 12 final event 20-21 May 2019, Bolzano
..in combination with the choice of insulation
Tersteeg, Hopfe, Allinson, 2018. : Hygrothermal assessment of two solid-brick walls under varying internal and external parameter
settings, Building Simulation and Optimization (BSO)18, Cambridge
Station 3
1 2
1 2
Station 3

10. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Case 6: IEA EBC Annex 71: “Building energy performance
assessment based on in situ measurements”
Source: Mantesi, Mourkos, Hopfe, McLeod, Strachan, Deploying Building Simulation to Enhance the Experimental Design of a Full-scale Empirical Validation
Project, BS 2020, Rome, Italy
Create a preliminary synthetic dataset of the experiment to evaluate the usability of
the real measurement dataset, before the actual experiment is conducted.

11. The Future Envelope 12 final event 20-21 May 2019, Bolzano
• Deterministic: actual experiment was
replicated in EPlus to create a
synthetic dataset
• Probabilistic: various uncertain
parameters were ranked according to
their impact
>> universally applicable method to be used as an adjunct to empirical
validation process in a multitude of building performance research
Novel procedure for incorporating virtual BPS experiments as diagnostic
precursor to support full-scale empirical validation. Both deterministic and
probabilistic simulations:
Source: Mantesi, Mourkos, Hopfe, McLeod, Strachan, Deploying Building Simulation to Enhance the Experimental Design of a Full-scale Empirical Validation
Project, BS 2020, Rome, Italy

12. The Future Envelope 12 final event 20-21 May 2019, Bolzano
Summary
When analysing the performance of facade elements, it is important
to have a better understanding of
• default settings (if using simulation tools),
• occupancy and internal room conditions
• material properties, in particular when planning with newer
facade elements
• climatic conditions and how this influences the choice of
materials
• heating, cooling and future behaviour
Absolute certainty may not be achievable - but a better
knowledge of uncertainty and risk is certainly possible!

13. The Future Envelope 12 final event 20-21 May 2019, Bolzano
• Toughness; the capacity to recover quickly from difficulties
• Strategies incorporating both robustness and other attributes such as
‘redundancy’ (or spare capacity) and adaptability are considered
increasingly important even on the micro-scale.
• at a micro-scale robustness-based design approaches dominate the
objective of achieving resilience.
Hopfe, CJ, McLeod, RS, Rollason, T. 2017 Opening the black box: Enhancing community design and decision making processes with building performance simulation, BS
2017
Source: earthshare.com
>>instead of achieving resilience
(whereby the building is able to
withstand a number of different impacts)
only single or multi-objective
optimization (e.g. is the building carbon
neutral) are actually typically considered
We need to build resilient buildings

14. References
• Mantesi, E., Hopfe, C. J, Cook, M. J., Glass, J. (2016). Investigating the impact of modelling
uncertainty on the simulation of ICF for buildings. Proceedings from BSO2016 Conference.
Newcastle, 12-14 September 2016, UK
• Mantesi, E., Hopfe, C. J, Goodier, C., Glass, J., Cook, M. J. , Strachan, P. (2018). The modelling gap:
Quantifying the discrepancy in the representation of thermal mass in building simulation
• Mourkos, K., Mantesi, E., Hopfe, C. J, Goodier, C., Glass, J., Cook, M. J. (2017). The Role of Fabric
Performance in the Seasonal Overheating of Dwellings. Building Simulation 2017.
• Mantesi, E., Hopfe, C. J, Glass, J., Cook, M. J. (2019). Empirical and Computational Evidence for
Thermal Mass Assessment: The Example of Insulating Concrete Formwork, Energy and Buildings,
188, 314-332
• Tersteeg, R., Hopfe, CJ, Allinson, D (2018) Hygrothermal assessment of two solid-brick walls under
varying internal and external parameter settings, Building Simulation and Optimization (BSO)18,
Cambridge
• Mantesi, E., Mourkos, K., Hopfe, CJ, McLeod, RS, Strachan, P., Kersken, M. (2019) Deploying Building
Simulation to Enhance the Experimental Design of a Full-scale Empirical Validation Project, BS
2020, Rome, Italy
• Hopfe, CJ, McLeod, RS, Rollason, T. (2017) Opening the black box: Enhancing community design
and decision making processes with building performance simulation, BS 2017
• Forde, J, Hopfe, CJ, McLeod, RS (2019), Temporal optimization of affordable Passivhaus dwellings:
is peak load a more reliable metric for cost optimal design?, Submitted to Applied Energy
The Future Envelope 12 final event 20-21 May 2019, Bolzano

15. Thank you for your attention!
www.interreg.net
Dr Christina Hopfe
Loughborough University
C.J.Hopfe@lboro.ac.uk
FACEcamp is funded by European Regional Development Fund and Interreg V-A Italy-Austria 2014-2020.