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.