1. for CoRE
fabric first and refurbishment excellence:
up-skilling to deliver the green deal and
beyond
may 2012
a natural materials
fabric first approach
to retrofit

2. Hanley 2010

5. built on clay

6. a living community

7. an architectural diversity
developed over time

8. Small window area give
minimum solar gain
23 St Lukes Street
- part of a unified, stepped terrace
- exit directly onto street
- east/west orientation
- uninsulated solid brick walls
- uninsulated solid floor
- tight for space internally
- gas fire heating only
- ‘hard to heat’ home

9. plan before
refurbishment
55m2
internal
floor area

10. heat loss through before refurbishment
chimney stacks
old gas boiler / hot water
tank in bedroom –
non airtight inefficient and noisy
construction
- major heat loss north-east facing glazed roof -
through loft hatch loses a lot of heat from house
- existing house
drafty
poor quality thermal north-east facing rear windows -
elements inadequate sunlight and
- no insulation, solid increased heat loss
external brick walls, building orientation =
solid ground floors minimal solar gain
and poor quality
glazing
no entrance lobby -
heat loss when front
door opened

11. energy performance
Pas s ivh au s Ene rp h it s tand ard
h e at d e m and * 670 kWh /m 2 yr m ax. 25 kWh /m 2 yr
TS B R e tro fit fo r th e Fu tu re targe t
p rim ary e ne rgy d e m and 765 kWh /m 2 yr M ax. 1 1 5 kWh /m 2 yr
air tigh tne s s
(air c h ange s p e r h o u r) 1 0.9h -h
TS B R e tro fit fo r th e Fu tu re targe t
C O 2 e m is s io ns 1 41 kg/m 2 yr m ax. 20 kg/m 2 yr
S AP rating 47** b and ‘E’
e ne rgy b ills £1 1 70 a ye ar
* to keep house at comfortable temperature of 21oC
** standard SAP rating taken from table 7.1, English House Condition Survey 2006

12. the challenge...
St Luke street St Luke street
existing energy retrofit energy
use use
90% reduction

13. natural materials retrofit approach
health non-toxic production /
disposal
no off-gassing
minimise allergies
low embodied energy carbon sequestering
bio-degradable
renewable materials
better indoor air quality naturally balances humidity
exothermic - ‘phase change’
protect existing fabric hygroscopic
vapour permeable
(‘breathing’)
prevent trapped moisture

14. Passivhaus building standard
highly insulated & airtight fabric
wall U-value = max. 0.15 W/(m²K)
roofs = max. 0.15 W/(m²K)
floors = max. 0.15 W/(m²K)
thermal bridge free
continuous air-tight layer
triple glazed windows
window U-value = max. 0.8 W/(m²K)
heat recovery ventilation
min. 75% efficient heat recovery
supplies fresh, warm air
low energy solar thermal hot water
AAA+ energy efficient electrical appliances

15. Passivhaus methodology retrofit
60000
Existing heat demand of 23 St Lukes Street = 33,000 kWh/yr = 660 kWh/sqm/yr
50000
40000
Passivhaus Standard = 15 kWh/sqm/yr
Passivhaus Enerphit = 25 kWh/sqm/yr
Improve Airtightness
30000
Heat Recovery
Ventilation
20000
Insulate South Wall
Insulate North Wall
Existing House
Insulate Floor
Triple-Glazed
Insulate Roof
0.20 W/m2K
0.15 W/m2K
0.10 W/m2K
0.15 W/m2K
Windows
10000
0
space heat demandHeat Demand (kWh/yr)
Total (kWhr/yr)
up to 80% reduction with fabric measures alone...
overall 97% reduction in heating demand = 22 kWhr/sqm/yr

16. typical variation in occupant use of energy

17. depth of insulation - design for it!
- front & rear elevations of
terrace usually shortest width
- chimney breasts removed to
improve airtightness
- compensated for floor area
lost to insulation
- extend kitchen with rooflight
- consider splaying reveals on
future projects

20. continuous insulation & air-tight layer
U-Value = 0.10
Internal wall External wall
Fo t
rn insulation insulation Ra
er
Eeaio
l tn
v U-Value = U-Value = Eeaio
l tn
v
0.20 0.15
New-solid floor
U-Value = 0.12
Air-tight layer

21. fabric first approach - walls
service zone
woodfibre insulation, fixed to
battens thru airtight layer
airtight membrane, vapour control layer
sheepswool insulation
between cross battens
solid brickwork with external render
0.15 W/m K2

22. avoiding thermal bridges - carefully detailed junctions
floor to wall
1. continuous insulation
2. thermal bridge free
3. continuous airtight layer

23. eaves detail

24. windows in the wall - St Luke street

25. new extension walls

26. fabric first approach - walls

27. woodfibre insulation to party walls

28. monitoring moisture : internal wall insulation
construction
drying out leaking gutter soaking wall

29. airtight detailing
what is the airtight barrier?
walls and roof: air-tight membrane
fully plastered wall
damp proof membrane
carefully detailed airtight junctions
tapes, windows, service penetrations
air-tightness buildability
communication between
designer and site team
careful site installation
attention to detail
methodical sequencing

30. heat recovery whole house ventilation
fresh, warm, low energy air
air supply will never be lower than 16.5℃due to
high efficiency of heat exchanger and frost
protection to unit.
ventilates the whole house
supply fresh air to living room and bedrooms
extract stale moist air from kitchen & bathroom + r ct of h t los es
edu ion ea s
+ limit a h midit / a oid
ir u y v
mou gr h
ld owt
find space for the unit and ducts + a oid bu
v ild-u of pollu a t
p t ns
careful planning required in existing house for + limit odou sr
ducts + clea in (f er )
n g ilt s
+ h t g & coolin
ea in g
+ ma a n gesh midit
u y
+ in ea ed comf t
cr s or

31. St Luke’s Street -
completed retrofit

32. St Luke street - results, calculated and measured
Exis ting H o u s e R e tro fit H o u s e
(50s q m ) (64s q m )
H e at d e m and * 670 kWh /m 2 yr 22 kWh /m 2 yr 97% R e d u c tio n
H o t wate r d e m and 27 kWh /m 2 yr 9 kWh /m 2 yr 65% R e d u c tio n
Ele c tric ity d e m and 38 kWh /m 2 yr 1 7 kWh /m 2 yr 55% R e d u c tio n
Air tigh tne s s
(air c h ange s p e r 1 0.9h -1 3.5 h -1 *** 78% R e d u c tio n
h o u r)
to tal p rim ary e ne rgy
788 kWh /m 2 yr 85 kWh /m 2 yr 89% R e d u c tio n
d e m and
C O 2 e m is s io ns 1 64 C O 2/m 2 yr 1 6 C O 2/m 2 yr 90% R e d u c tio n
S AP Rating 47** 90
p re d ic te d e ne rgy b ills £1 1 70 a ye ar £1 21 a ye ar 90% R e d u c tio n

33. resident experience
“We are delighted to have the
opportunity to be involved with this
ground breaking project. We feel it is
an innovative way of creating an
energy efficient and economical
home.”
“After our first two months here, we
love our eco-house, and enjoy living
here, and it’s good to feel
environmentally responsible without
having to make vast lifestyle changes.“
Mr and Mrs Watt

34. what did we learn?
• Whole house approach
• Educated project team and committed contractor essential
• Joint working opportunities between development
and asset management teams
• Found out more about particular technologies, materials
& processes
BUT …limitations
• Replicability
• Cost
• Enthusiasm from residents
• Only one particular house type

35. be bold
well wrapped up
airtight
well ventilated
where next for Stoke?

36. where next ?
simple measures on a whole terrace scale
create local employment
maximise learning and practising new skills,
airtightness building techniques,
once learnt never forgotten
part selfbuild by residents
providing timebank
to reduce rents

37. the retrofit challenge
• UK Government target to reduce
carbon emissions by 80% by 2050
• 85% of all buildings in existence
today will still be here in 2050
• how best to cost stock
improvements?
• a whole new approach to asset
management?
• Sophie Atkinson - Sanctuary HA

38. th anks to - th e p ro j c t te am
e
Client: Sanctuary Group
Architect: Anne Thorne Architects LLP
Contractor: Seddon Construction Ltd
Quantity Surveyor: McBains Cooper
Services and Structural Engineer: King Shaw Associates
Monitoring: Building Sciences Ltd