This document describes a retrofit project at 20 Warrenhouse Road to improve energy efficiency and reduce carbon emissions. The retrofit involved rebuilding the property with enhanced insulation, new windows and doors, an exhaust air heat pump system, and solar panels. As a result, the property's annual carbon emissions decreased from 152.63 to 15.47 kg/m2/year and is predicted to have annual energy costs of £458, meeting the standards of Code Level 4 for sustainable homes.

1. 20 Warrenhouse Road
Fabric and Further Retrofit
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

2. Aim
Develop a single property fabric
and further approach to retrofit
and climate change that can be
applied to void properties in need
of significant repair.
Existing
CO2 emission 152.63 kg/m2/year
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

3. Project Outcomes
It is anticipated that the completed
project will display significant cost
and carbon savings relating to the
property heating requirements. This
project will also explore further
mitigation to climate change
measures resulting in a reduced
environmental impact
Completed
CO2 emission 15.47kg/m2/year
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

4. Project Outcome
Predicted annual energy costs of
£458
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

5. Project Outcome
Predicted annual energy costs of
£458
Dwelling Emission Rate (DER)
equivalent to Code for Sustainable
Homes Level 4
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

6. Project Outcome
Predicted annual energy costs of
£458
Dwelling Emission Rate (DER)
equivalent to Code for Sustainable
Homes Level 4
Air Permeability score of
2.74m3/(h.m2)
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

7. Project Outcome
Predicted annual energy costs of
£458
Dwelling Emission Rate (DER)
equivalent to Code for Sustainable
Homes Level 4
Air Permeability score of
2.74m3/(h.m2)
Great new home for First Ark
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

8. The Process
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

9. Rebuilding
Removed existing windows
and doors
Created new roof
Formed internal walls &
Intermediate floor
Cleared overgrown site
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

10. The Fabric
200mm Enhanced
Polystyrene – 0.15W/m2K
150mm Icynene spray foam
insulation with 600 PIR –
0.15W/m2K
Double glazed windows
Composite Door
Air tightness score of 2.74
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

11. The Further
Exhaust Air Heat Pump and
Mechanical Ventilation
System
Under floor heating, no heat
source to first floor
2kW peak PV array
Voltage Optimisation
Rainwater harvesting system
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

12. Air Permeability
Spray foam insulation with
taped PIR
DPM and Tyvek DuPont
AirGuard Reflective lapped
into British Gypsum
Soundcoat Plus Parge Coat
Tested at 4 stages
m3/hr/m2@50Pa
Water tight 60
1st fix 6.25
2nd fix 3.78
completion 2.74
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

13. m3/hr/m2@50Pa
64
32
16
Axis Title
m3/hr/m2@50Pa
8
4
2
1
Water tight 1st fix 2nd fix completion
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

14. The Result
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit

15. First Ark’s most energy
efficient property…
meeting the 2050
climate change targets
J O H N M c C A L L A R C H I T E C T S
20 Warrenhouse Road - Retrofit