Housing typologies
Ian Page, BRANZ
Typologies- Houses with similar
characteristics
►Why use typologies? To identify:
1. House characteristics by component, which
influences the ability to retrofit.
2. Occurrence of existing efficiency measures.
3. The size of the job – i.e. house numbers in the
various typologies.
4. To develop packages of measures by typology.
5. Prioritising (i.e. which groups need most
attention.)
Data Sources
►Census 2006 of Households and Dwellings.
►Quotable Value database.
►BRANZ House Condition Survey 2004 (565
houses).
►Household Energy End-use Programme
(HEEP 397 houses).
TYPOLOGIES
1. Villa (1880 – 1920)
2. Bungalow (1920 – 1930/40)
3. Art Deco (1925 – 1940)
4. State Housing / mass housing (1940 – 1960s)
5. Pre-1960 Multi Unit Housing (1950-60s)
6. 1960/70s Multi Unit Housing (1960-70s)
7. Mass Housing (1970 – 1978 pre-insulation)
8. Mass 80’s Housing (1978 – 1989)
9. Multi-unit housing 1980-90s
10. Early 90’s (1990 – 1996 pre re-vamped building code)
11. Last decade housing (1996 – 2007) (post insulation upgrade)
12. Multi-unit dwellings (2000 – 2009)
TYPOLOGIES
What data is useful?
►Age of house (particularly if pre-1979).
►Any ceiling insulation and if so how much?
►Any floor retrofit insulation?
►Sub-floor and roof space clearances.
►Window/ cladding and linings condition.
►Chimneys/ fireplace (space for installing
efficient heaters.)
►House size.
Ceiling insulation
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Pe
rce
nt
Decade starting
Ceiling insulation - Zone 1
>100mm
100mm
75mm
50mm
None
Source: 2004 HCS and HEEP.301 houses.
Ceiling insulation
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Pe
rce
nt
Decade starting
Ceiling insulation - Zone 2
>100mm
100mm
75mm
50mm
None
Source: 2004 HCS and HEEP. 124 houses.
Ceiling insulation
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Pe
rce
nt
Decade starting
Ceiling insulation - Zone 3
>100mm
100mm
75mm
50mm
None
Source: 2004 HCS and HEEP.160 houses.
Sub-floor clearances
1940s to 1970s are favourable for floor retrofit.
Chimneys
Pre-1970s have high incidence of fireplaces and hence room to retrofit an
efficient space heater (solid fuel, gas).
Wall linings (interior)
1930s, 1940s and 1950s have a high incidence of houses with less than
“Good” linings condition, and which may be candidates for re-lining.
Average size
1940s to 60s houses are comparatively cheap to retrofit.
Other characteristics
Easy wins where maintenance or
replacement is required…
•Wall cladding in 1930’s houses
•Windows prior to 1960
•Hot water cylinders in 1960’s
houses0
5
10
15
20
25
30
35
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
% o
f h
ou
ses
wit
h p
oo
r w
ind
ow
co
nd
itio
n
Decade starting
Windows - poor condition incidence
Source: 2004 HCS, 564 houses.
0
5
10
15
20
25
30
35
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
% o
f h
ou
ses
wit
h p
oo
r/ s
eri
ou
s w
all
cl
ad
din
gi
con
dit
ion
Decade starting
Wall cladding - poor condition incidence
Source: 2004 HCS, 564 houses
Scoring housing characteristics for
“retrofitability”.
Scoring for retrofit by typology
Bungalow Art Deco Mass hse Multiunits House House Multiunit House House Multiunit
Villas 1920-36 1925-40 40s-60s 60-70s 1970-78 1978-80s 1980-90s 1990-96 post 96 2000s
Component characteristics (1)
0= Unfavourable, 1= Moderate 2 =Favourable
Sub-floor clearance 0 0 0 2 1 1 1 1 0 0 0
Roof space 2 2 0 1 1 0 1 1 1 1 1
Chimney space 2 2 1 1 0 0 0 0 0 0 0
Windows condtn 1 1 2 1 1 1 0 0 1 1 1
HW Cylinder age 0 0 0 2 1 1 0 0 0 0 0
Existing ceiling insult 1 1 1 2 1 2 1 1 1 0 0
Total (2) 6 6 4 9 5 5 3 3 3 2 2(1) Each decade is scored on a 3 point scale for the favourability or otherwise of retrofit of the component.
(2) The higher the more favourable the decade is for retrofit. Each component is equally weighted, i.e scores are added.
Villas, 20s Bungalows and 40s-60s mass housing score best.
Villas Pre-1915 and Bungalows1920-35
1. Good candidates for retrofit.
2. Good ‘bones’ with sound
native timbers.
3. Retrofit insulation in ceiling
and floor relatively easy.
4. Often oriented to the street as
opposed to the sun.
5. Double glazing their windows
is difficult.
6. Often need relining, providing.
opportunity for wall insulation.
Art Deco 1925-1940s
1. Bad candidates for retrofit.
2. Skillion roof difficult to retrofit.
3. Often with renovated roof on
top due to previous failures.
4. Built low to the ground with
lack of crawl space.
5. But highly valued so owners
may go the extra mile.
Mass housing 1940s-60s
1. Good candidates for retrofit.
2. Well oriented.
3. Hipped roof with 40 degree
pitch.
4. Good access in ceiling and
floors.
5. Small spaces may prioritise
heating systems such as heat
pumps or inset wood burners.
6. Original HWCs in 1960s
houses.
Mass housing 1970s
1. Large numbers built before
insulation required.
2. Variable cladding (fibre cement,
reconstituted timber, stucco,
weatherboard,...). Variable
condition.
3. Timber floors, moderate clearances.
4. First use of aluminium windows,
sliding doors.
5. Skillion roof, exposed ceiling rafters.
6. Garage underneath quite common.
Can be difficult to retrofit due to low
roof and skillion roofs. Wall cladding
and windows often need replacing.
Mass housing 1980s to mid 90s
1. Mixed cladding types, usually on
concrete slab. Reasonably
airtight and has wall insulation
2. Ventilation and IEQ may be
important issues
3. Leaky buildings from 1990 with
monolithic style.
4. Additional ceiling insulation may
be worthwhile.
Outcome of the typology approach
►Typologies help identify good candidates for
retrofit.
►Typologies help quantify the numbers of
houses worth retrofitting.
►Can roughly estimate the cost of a package
of measures for each typology without
individual inspection.
►Combine typology data with cost and energy
models to estimate the potential NZ wide
savings.