1. Cracking the Code: Energy and CO2
Malcolm Bell
Buildings, Energy and Sustainability Group, School of the Built Environment, Leeds Metropolitan University, Leeds, UK.
Paper presented to: The Code for Sustainable Homes: Cracking the Code Seminar March 2007, Birmingham, UK.

2. Racking up the energy/CO2 points

3. Target Emission Rate – the TER
partially offsets higher carbon intensities of fuels other than gas (electricity, oil, lpg etc.
Target Emission Rate
kg (CO2)/m2/a
CO2 emissions for lighting
TER = (CH x fuel factor + CL) x (1- Improvement)
CO2 emissions for ventilation, and space & water heating for the notional dwelling
Improvement factor = 0.2 i.e. a 20% reduction

4. The TER thresholds

5. Target Emission Rate – the TER

6. TER - Threshold values
- 10%
- 18%
- 25%
- 44%
circa -135% to -150% ??

7. The TER points scale

8. TER – Threshold compliance packages
80m2 Semidetached 2 storey house

9. TER – Base Case
TER-06 - gas & bio
TER-06 - electricity
Bio: would meet the threshold for 4 Star = 12.9 code points

10. TER – 1 (-10%)
TER-06 - gas & bio
TER-06 - electricity

11. TER – 2 (-18%)
TER-06 - gas & bio
TER-06 - electricity

12. TER – 3 (-25%) TER-06 - electricity TER-06 - gas & bio
Target = 24.77
Actual = 24

13. TER – 4 (-44%) TER-06 - electricity TER-06 - gas & bio
Target = 18.49
Actual = 17

14. Passive House Standards
Timber frame scheme Göteborg, Sweden (120 m2)
Airtightness 1 m/h
Source: Wall (2006), Photo: Hans Eek
MVHR – 80% with duct heaters
5m2 Solar water + resistance top-up

15. Passive House Standards
Timber frame scheme Göteborg, Sweden
Source: Wall (2006), Photo: Hans Eek
TER (kgCO2/m2)
Design ≈ 10.6
Actual ≈ 15.3
Under Swedish conditions!
Source: Wall (2006), Energy and Buildings. 38, pp

16. TER – 5 (-100%) Net TER = 0 TER-06 - electricity
TER-06 - gas & bio
TER-06 - electricity
Net TER = 0

17. TER – 6 (-135% to -150%)
Appliances

18. The place of energy & CO2 One of many scenarios
Note: “Other energy” is modelled to balance TER & other energy points in each class

19. Models and Management
Stafford Beer’s presidential address to the Society for General Systems Research at the Annual Meeting of the American Association for the Advancement of Science, 1971 (Beer 1973) 13

20. Managing the world ?
Reality
Management
Model

21. The effects of time
Management
Model
Reality ? ?
Time

22. Feedback on performance: Airtightness

23. Hidden air paths
Behind plasterboard

24. Hidden air paths
Internal partitions

25. Thermal bridging & construction
Designed performance is almost always degraded

26. Construction issues: window lintel
As Designed = 42mm gap
Ψ value = W/mK
Typical As Built = 20mm gap
Ψ value = W/mK
+164%

27. Understanding complex heat loss paths
Party wall heat bypass

28. Only if we use it to manage the real world
Cracking the Code? ?
Only if we use it to manage the real world