This document discusses a conference on beyond zero carbon housing held at the University of Nottingham. It begins by introducing the concept of a zero carbon hierarchy to help define zero carbon goals. It then covers topics discussed at the event including fabric energy efficiency standards, carbon compliance targets, understanding the impact of the 2011 budget changes, lessons from case studies on performance gaps between design and implementation, and monitoring in-use energy consumption.

1. Beyond Zero
Carbon Housing
exploring solutions to sustainability issues
beyond the zero carbon agenda
2 4 th O c t o b e r 2 0 1 2 a t T h e U n i v e r s i t y o f N o t t i n g h a m
Department of Architecture and Built Environment

2. ©
Copyright Notice
A l l t h e m a te r i a l i n t h e s e s l i d e s
m ay n o t b e u s e d o r re p ro d u c e d w i t h o u t t h e
ex p re s s p e r m i s s i o n o f t h e a u t h o rs

3. Beyond Zero Carbon
Policy and Practice
Richard Partington

4. ZERO CARBON HIERARCHY
Zero Carbon =
Solutions
addressing the
carbon emission
5%
Allowable reductions that
are difficult to
Complete
solutions achieve on site
On-site low/zero
+
Carbon
75%
Compliance =
carbon energy On-site heat and
Complete
(and connected heat) power generation
+
Energy efficiency Building fabric 95%
performance
Complete
The Zero Carbon Hierarchy – stepped progress towards a workable definition.

5. Fabric Energy Efficiency
Building fabric U-values
Thermal bridging
Air permeability
LZC technology Thermal mass
Solar, metabolic, lighting &
appliance gains
Heat
Heating / cooling
appliances (boilers, etc)
Power
Mechanical ventilation
Hot water
Active controls
Fixed lighting
All LZC technologies

6. Understanding the BUDGET 2011
CO2 emissions
from unregulated
energy use
Allowable
Solutions Allowable
Solutions CO2 emissions
from regulated
On-site LZC Heat On-site LZC Heat energy use
and Power and Power
Fabric Energy Efficiency Fabric Energy Efficiency
Pre-Budget 2011 Post-Budget 2011

7. STEP 1 2016 FABRIC ENERGY EFFICIENCY
STANDARD (FEES)
Fabric Energy Efficiency of 39 kWh/m2/year for apartments & mid terrace
46 kWh/m2/year for end terrace, semi and detached
Performance not prescriptive No U-value lists/limits on elements. Uses kWh/m2/yr.
For simplicity - space heating and cooling only.
Two levels depending on dwelling type
However same construction delivers 39 or 46, except in the case of the detached

8. STEP 2 2016 CARBON COMPLIANCE
Target Carbon Compliance of 10 kg CO2/m2/year for detached homes
11 kg CO2/m2/year for attached homes
14 kg CO2/m2/year for apartments
Approach provides solutions for a range of practical situations:
.
On gas grid On gas grid Off gas grid Community Heat
‘PV’ ‘Fabric’ Heat Pump Network

9. JOURNEY TO ZERO CARBON
THE 2011 BUDGET CHANGE
25% reduction CO2 emissions from
regulated energy
3 31% reduction
X
44% use – space and
4
water heating, fans,
pumps and fixed
lighting
5
100% reduction
CO2 emissions from
66 unregulated energy
use – cooking and
plug-in appliances
Zero
Carbon
Pre 2010 2010 2013 2016
2016
CO2 emissions CO2 emissions CO2 emissions CO2 emissions from
Zero CO2 emissions
from a home from a home from a home regulated and
from regulated
built to 2006 built to 2010 built to 2013 unregulated energy
energy use
Part L1A Part L1A Part L1A use to be net zero

10. Design vs ‘As-built’:
Lessons from TSB Programme

11. Performance gap
‘action is needed by industry and
Government to investigate and
tackle the risk of a discrepancy’
2012 Part L Consultation

12. Does it do what it says on the tin?

13. Research Project Overview: Project Focus
Block B: Code for
Sustainable Homes
Level 3 (using no
renewables)
Block C: Fabric
Energy Efficiency
Standard (FEES)
Wide Cavity
13

14. Fabric Performance Investigations
& Observations

15. In-situ U-value measurement
Test gives: In-situ U-value measurement
Methodology
Heat flux testing carried out during co-heating
test in one flat in each block
Heat loss measured across north-facing
external walls and also party walls
Observations
The difference in measured and calculated
U-values is similar to tests of this nature
A party wall bypass was noted in both blocks
15

16. Thermographic imaging
Method
Internal & external images of the
building fabric taken during the co-
heating testing
Carried out early in the morning to
minimise distortion to surface
temperatures
Observations
Thermographic images reveal
weaknesses in the build and design
Analysis must be carried out by an
experienced person
16

17. Photographic survey of construction
Record of actual construction
Method
Document the construction process
Additional photography to support air
pressure tests, co-heating and
commissioning
Observations
Construction stage for analysis of
thermography results at a later stage
Specific problems noted during the air
pressure test were communicated to
site personnel
17

18. Co-heating test
Observations on implementation
Test carried out in April, at very end
of what is considered the suitable
period
Active site, so difficult to maintain
controlled temperature in adjacent
units
Observations on results
Measured heat loss was greater
than calculated heat loss
Result at higher end of scale of
published test results
18

19. Houses measured by
Leeds Metropolitan University
Heat loss (w / k)
Whole house heat loss - Measured Co-heating versus Predicted

20. Drawings and accredited details
Domestic services commissioning

21. Drawings and specification

22. Drawings and specification:
claimed use of accredited details

23. Thermographic imaging

24. Enhanced, Accredited, Robust?

25. Construction images
25

26. MVHR Installation and Commissioning
26

27. MVHR Installation and Commissioning
27

28. MVHR Installation and Commissioning
28

29. MVHR Installation and Commissioning
29

30. MVHR Installation and Commissioning
30

31. MVHR Installation and Commissioning
31

32. Monitoring: In-use energy consumption
Fuel and resource consumption:
Gas, electricity and water
metering
Electric sub-metering

33. Mind the Gap

34. Mind the Gap

35. Derwenthorpe and Temple Avenue

36. Type A Prototypes

37. Two MMC construction system
thin bed blockwork
structural insulated panel
design intention delivered?
did systems meet claimed
performance?
was the supply chain robust?
interfaces communicated and
understood ?
sub-contractor performance
product substitutions and changes
were modelling assumptions correct?
lessons for a volume build

38. Temple Avenue Prototype Houses

39. Temple Avenue Prototype Houses
Construction
Co-heating test
Thermography
Heat flux measurement
Systems efficiency
Air pressure and
gas depletion
Variable U-value

40. Derwenthorpe Phase One Houses
Construction
Inner leaf first:
watertight early
large format insulation
insulation visible
facing brick off
the critical path

41. Derwenthorpe Phase One Houses
Consistency:
Airtightness 2.7–3.0
Co-heat test within
10% of prototypes

43. BEST PRACTICE BOOKLETS
NHBC and Zero Carbon Hub
NHBC Foundation NF 28:
http://www.nhbcfoundation.org/Researchpublications/WheretoStartNF28/tabid/444/Default.aspx
ZCH Best Practice:
http://www.rparchitects.co.uk/practice/publications/building-low-carbon-homes-guide-3-icf