Energy and Carbon Performance of Housing:Upgrade Analysis, Energy Labelling and National Policy

Development

Joe Clarke, Cameron Johnstone, Jae-min Kim, Paul TuohyEnergy Systems Research Unit, University of Strathclyde

Simulation has the potential to underpin

future legislative requirements of the

EPBD.

Scottish Building Standards Agency

funded work to investigate national

domestic stock upgrades and

individual dwelling certification.

1. Stock: 2,278,000 dwellings with a high refurbishment requirement.

2. Dwelling types: detached, semi-detached, terraced, tenement (flats with shared access), four-in-a-block, tower block, conversions.

4. Construction system: cavity wall (72%), solid wall (28%).

3. Materials: brick/block (67%), sandstone (18%), whin/granite (4%), non-traditional (10%).

5. External finish: rendered (71%), stone (18%), brick (5%), non-traditional (5%).

6. Energy: dwellings comprise a high proportion of overall energy consumption 14.5 TWh/yr (5.5 MT CO2) for heating against a total demand of 85 TWh/yr.

Project context: Scotland

2. General

mean National Home Energy Rating is 4.1 (0 poor - 10 good)

need for energy efficiency improvements

fuel poverty, hypothermia, condensation and mould growth are concerns

1. Insulation and heating systems

80% have loft insulation (only 12% meet the 1991 building standards)

92% have hot water tank insulation (5% to an unacceptable level)

74% have pipe insulation (13% to an unacceptable level)

70% have gas central heating (14% are partial installations)

Stock performance

Legislative questions what upgrades offer best value?

what deployment combinations are suited to the

different house/construction types?

how should the deployments be phased over time?

can simulation be used to answer such questions?

Relevant upgrades wall, floor, loft, tank and pipe insulation draught-proofing heating system and control improvements double/advanced glazing low energy lights and appliances solar thermal/electric wind energy recovered heat

EDEM model constructed by applying the ESP-r system to the national housing stock

Problematic because of the many permutations of house types, constructional systems and upgrade measures.

Easy to identify dwelling types from an architecture and construction (A/C) viewpoint, but ….

• dwellings belonging to the same A/C group may have different energy consumption (/m2) due to dissimilar energy efficiency measures having been applied;

• dwellings corresponding to different A/C groups may have the same consumption because the governing design parameters are essentially the same.

=> operate in terms of TCs not A/C types.

EDEM: stock modelling

Assume thermodynamic classes (TC) where different A/C types may belong to the same TC.

There are 6,480 TCs each representing unique combination of 7 fabric and 6 system design parameters that may exist at several levels.

Determine the normalised energy performance of each TCs by simulation.

Relate existing or proposed dwellings to a TC via the present level of its governing design parameters.

Should any design parameters be changed as part of an upgrade then that house is deemed to have moved to another TC.

TCs therefore represent all possibilities now and in the future.

Project method

Dwelling model: comprises living, eating and sleeping areas has typical usage patterns, exposures and control set-points has TC specific design parameters applied is subjected to long term representative climate

Simulation context may be varied to represent future scenarios (e.g. climate change or improved living standards).

universe of possibledwellings

• poor insulation• low mass• small windows• leaky• …

• well insulated• high internal mass• large windows• well sealed• …

discrete designs

6,480 simulatedmodels

inherited behaviour

TCs are unique combinations of construction parameters:

insulation level (6) capacity level (2) capacity position (3) air permeability (3) window size (3) exposure (5) wall-to-floor ratio (2)

and systems parameters: fuel type (5) plant type (8) plant efficiency (3) DHW (3) RES type (3) RES scale (3)

giving 2 x 3,240 combinations representing the universe of possibilities.

Thermodynamic class (TC) determinant parameters

Parameter Values Comments

insulation U of wall, floor, roof, glazingpoor 1.80 0.86 0.93 5.1 pre 1965mid 0.60 0.45 0.35 3.3 1981 regulations

warm 0.30 0.25 0.16 2.2 2002 regulationsgood 0.25 0.22 0.16 1.8 2007 regulationsint 0.15 0.15 0.10 1.4 intermediate

super 0.10 0.10 0.10 0.8 advanced

infiltration Air change ratepoor 1.5 typical

standard 1.0 1997 regulationstight 0.5 best practice

capacity effusivity (Jm-2K-1s-1/2)low 675 timber frame or drylinedhigh 1285 plaster on solid

exposure number of exposed surfacesfm 3 sides, 0 roof/floor 3 external surfacesftg 3 sides, 1 roof/floor 4 external surfacesmt 2 sides, 2 roof/floor 4 external surfaces

sdet 3 sides, 2 roof/floor 5 external surfacesdet 4 sides, 2 roof/floor 6 external surfaces

wall ratio number of storeyslow 1 walls lower % of envelopehigh 2 walls higher % of envelope

Insulation:

Infiltration:

Glazed area:

Capacity:

Gains:

Operation:

Exposure:

Hot water use:

Heating system efficiency:

poor ave high eco

leaky ave tight

Climate:

Low carbon heating:

std large

low high

high low med

frugal ave profl

high

std future

high no med

profl frugal ave

high low med

h-m

UKCIP

m-lave low

super

Energy performance characterised by the appropriate combination of key parameters

Energy efficiency lights:

Appliances:

Low carbon electricity: high no med

all no med

high low med

high low med

high low med Water heat sys efficiency:

Emissions factors:

EDEM: performance rating

individual dwelling statement

performance current equivalent

(kgCO2/m2.yr) rating new build

rating

A+ (-20-0)

A (0-15)

B (15-30) B C (30-45)

D (45-60)

E (60-80)

F (80+) F

Fabric loss (exp, ins):

Infiltration:

Glazed area:

Capacity:

Gains:

Operation:

Hot water use:

Energy efficiency lights:

Appliances:

Low carbon electricity:

Heating system efficiency:

v.high high ave low

leaky ave tight

Climate:

Low carbon heating:

std large

low

std

std

std

high no med

high no med

std

all no med

high low med

std

high low med Water heat sys efficiency:

v.low

Emissions factors:

EDEM: performance rating, SAP emulation

individual dwelling statement

performance current equivalent

(kgCO2/m2.yr) rating new build

rating

A+ (-20-0)

A (0-15)

B (15-30) B C (30-45)

D (45-60)

E (60-80)

F (80+) F

Options may be restricted to align with SAP 2005 assumptions

TC Parameters Regression equation coefficients

a b c d e f g h i j k 1 1/0/2/2/0 -1.003 -0.008 -0.115 0.0097 0.0008 0.0052 -0.110 0 0.0009 0.0130 22.7 2 0/0/2/2/0 0.181 -0.015 -0.157 0.2350 -0.0020 0.0013 -0.190 0.00010 0.0030 0.0204 17.4 3 1/0/1/1/1 -0.946 -0.005 -0.106 -0.0080 0.0009 0.0044 -0.107 0 0.0006 0.0128 21.5 4 0/0/0/0/0 -0.755 -0.007 -0.100 -0.0940 0.0028 0.0012 -0.121 0 -0.0020 0.0171 22.9 5 0/0/0/1/0 -0.969 -0.009 -0.112 0.0387 0.0009 0.0052 -0.105 0 0.0010 0.0127 21.6 6 0/0/1/2/0 -0.889 -0.007 -0.098 0.0155 0.0007 0.0046 -0.096 0 0.0009 0.0130 19.7 7 1/1/1/0/0 -0.857 -0.011 -0.113 0.0048 0.0010 0.0054 -0.102 0 0.0007 0.0127 19.2 8 1/1/0/1/0 -0.854 -0.011 -0.112 0.0060 0.0010 0.0053 -0.102 0 0.0007 0.0127 19.1 9 1/0/0/0/2 -0.855 -0.011 -0.113 0.0064 0.0010 0.0054 -0.103 0 0.0007 0.0128 19.110 1/0/0/1/2 -0.856 -0.011 -0.114 0.0078 0.0010 0.0055 -0.104 0 0.0008 0.0129 19.211 1/0/1/2/2 -0.800 -0.010 -0.100 0.0093 0.0011 0.0048 -0.100 0 0.0008 0.0123 17.712 1/0/2/1/2 0.915 -0.013 -0.229 0.0491 -0.0060 0.0047 -0.220 0.00040 0.0081 0.0194 12.313 0/0/2/0/2 -0.685 -0.003 -0.086 0.0552 0.0007 0.0038 -0.083 0 0.0002 0.0105 14.514 0/0/1/1/2 -0.742 -0.005 -0.105 0.0579 0.0007 0.0053 -0.083 0 0.0007 0.0103 15.215 1/1/2/0/1 0.001 0.007 -0.113 -0.0240 -0.0020 0.0014 -0.072 0.00020 0 0.0096 11.016 1/2/2/2/0 -0.610 -0.003 -0.087 0.0602 0.0007 0.0043 -0.076 0 0.0008 0.0091 12.417 0/1/1/0/1 -0.610 -0.003 -0.087 0.0604 0.0007 0.0043 -0.076 0 0.0008 0.0091 12.418 0/1/1/2/1 -0.523 -0.009 -0.097 0.0134 0.0002 0.0051 -0.072 0 0.0006 0.0090 11.619 0/1/2/2/1 -0.557 -0.009 -0.096 0.0489 0.0005 0.0053 -0.071 0 0.0007 0.0090 11.520 1/1/1/1/2 -0.555 -0.009 -0.096 0.0487 0.0005 0.0052 -0.071 0 0.0007 0.0090 11.421 1/1/2/2/2 -0.196 -0.006 -0.092 -0.0190 -0.0010 0.0034 -0.063 0.00003 0.0013 0.0073 10.022 0/1/1/0/2 -0.469 -0.006 -0.084 0.0527 0.0005 0.0045 -0.070 0 0.0009 0.0085 9.723 1/2/1/2/0 -0.465 -0.009 -0.102 0.0130 0.0002 0.0053 -0.071 0 0.0006 0.0091 10.524 0/2/1/0/1 -0.396 -0.005 -0.088 0.0425 0.0001 0.0047 -0.068 0 0.0010 0.0080 8.725 0/1/0/1/2 -0.425 -0.007 -0.076 0.0547 0.0005 0.0042 -0.065 0 0.0094 0.0078 8.626 0/2/0/2/1 -0.389 -0.005 -0.086 0.0396 0.0001 0.0046 -0.066 0 0.0091 0.0078 8.627 1/2/0/2/2 -0.237 -0.009 -0.074 -0.0050 0 0.0040 -0.046 0.00004 0.0002 0.0063 6.028 1/2/1/0/2 -0.228 -0.009 -0.069 -0.0060 0 0.0038 -0.042 0.00004 0.0001 0.0058 5.629 0/2/0/0/2 -0.159 -0.005 -0.053 0.0079 0 0.0032 -0.036 0.00002 0.0004 0.0043 3.930 0/2/1/2/2 -0.157 -0.005 -0.052 0.0077 0 0.0031 -0.035 0.00002 0.0004 0.0043 3.9

E = a θ + b Rd + c Rf + dV + e θ Rd + f θ Rf + g θ V + h Rd Rf + i RdV + j Rf V + k

large windows, poor insulation, high capacity (externally located), high infiltration, …

Dwelling Type

Detached Semi-detached Terrace Tenement flat 4-in-a-block As built As As As As built #1 built #1 built #2 built #1

Heating demand 43 71 43 87 41 81 34 66 30(kWh m-2y-1)

TC model 13 30 18 28 13 29 21 11 26TC heating 46 76 46 91 46 87 34 67 26(kWh m-2y-1)

% difference 7 7 7 5 12 7 3 2 -13

#1: with double glazing, cavity and loft insulation and draught proofing.#2: with double glazing, internal insulation and draught proofing.

EDEM validation (v. measured and full scale simulation)

EDEM validation (v. published NHER ratings)

0

20

40

60

80

100

120

140

160

0 20 40 60 80 100 120 140 160

NHER

EDEM

EDEM (Electric) EDEM (Gas)

Certificate and improvement advice

Individual dwelling

statement

EDEM: application scale

performance current equivalent

(kgCO2/m2.yr) rating new build

rating

A+ (-20-0)

A (0-15)

B (15-30) B C (30-45)

D (45-60)

E (60-80)

F (80+) F

Individual dwelling EPBD rating and action

plan generation

EDEM

Stock rating and upgrade strategy appraisal

performance current equivalent

(kgCO2/m2.yr) rating new build

rating

A+ (-20-0)

A (0-15)

B (15-30) B C (30-45)

D (45-60)

E (60-80)

F (80+) F

Scottish housing stock

0

10

20

30

40

50

60

1996 2002 2020A 2020B 2020C

Em

iss

ion

s App

Lights

HW

Heat

Scottish house condition survey

CONTEXT

policy, climate, fuel, demographics,

economics

EDEM in use

property description carbon emission rate

performance current equivalent

type det (kgCO2/m2.yr) rating new build

footprint 45 rating

storeys 2 A+ (-20-0)

window size 10 A (0-15)

infiltration poor B (15-30) Binsulation poor C (30-45)

heating system g(old) D (45-60)

low energy lighting 0% E (60-80)

renewable energy no F (80+) F

EDEM in use: emissions label

property description carbon emission rate

performance current equivalent

type det (kgCO2/m2.yr) rating new build

footprint 45 rating

storeys 2 A+ (-20-0)

window size 10 A (0-15)

infiltration poor B (15-30) Binsulation high C (30-45)

heating system g(old) D (45-60) Dlow energy lighting 0% E (60-80)

renewable energy no F (80+)

high insulation level:

property description carbon emission rate

performance current equivalent

type det (kgCO2/m2.yr) rating new build

footprint 45 rating

storeys 2 A+ (-20-0)

window size 10 A (0-15)

infiltration tight B (15-30) Binsulation high C (30-45) Cheating system g(old) D (45-60)

low energy lighting 0% E (60-80)

renewable energy no F (80+)

tight air leakage:

property description carbon emission rate

performance current equivalent

type det (kgCO2/m2.yr) rating new build

footprint 45 rating

storeys 2 A+ (-20-0)

window size 10 A (0-15)

infiltration tight B (15-30) B Binsulation high C (30-45)

heating system g(new) D (45-60)

low energy lighting 0% E (60-80)

renewable energy no F (80+)

new heating system:

SAP rating

current

A (100-120)

B (85-100)C (70-84)D (55-69)E (40-54)F (25-39) 34G (1-24)

annual fuel cost: £802

SAP rating

improved

A (100-120)

B (85-100) 85C (70-84)D (55-69)E (40-54)F (25-39)

G (1-24) annual fuel cost: £198

current rating

improved rating

Current Property

size:

footprint 60 storeys 1

type:

House type: det,sd-et,mt,flat flat

Window %TFA: (10 or 25): 10

parameters:

Airflow: tight, std, poor: poor

Insulation: high, std, poor poor

Heating: el, g(old), g(new) el

LEL: 0%, 50%, 100% 0%

RES: no,shw,(pv+shw tbd) no

Improved Property

parameters:

Airflow: tight, std, poor: poor

Insulation: high, std, poor poor

Heating: el, g(old), g(new) g(new)

LEL: 0%, 50%, 100% 0%

RES: no,shw,(pv+shw tbd) no

ENERGY CERTIFICATE

improvement advice

EDEM in use: energy certificate

household questionnaire

EDEM application: national scale

Date

Type

Pre 1919-65 (64%) 1965-82 (25%) 1982-02 (11%)

Cavity Solid Non-trad.

Cavity | Solid

Cavity Solid Non-trad.

Cavity | Solid

Cavity

Timber | Trad.

Houses

Detached 4% 5%     4%   0.5% 0.5% 2% 

2% 

18%

Semi-detached 8% 5%     4%   0.5% 0.5% 1.5% 1.5  21%

Terraced 8.5% 3.5% 0.5 0.5% 6%   1.5% 1.5% 1%  1% 24%

Flats

Tenement 6% 9% 1% 1% 3%   0.5% 0.5% 1% 1% 23%

Four-in-a-block 6% 2% 0.5% 0.5% 0.5%     0.5%     10%

Tower block 1%   0.5%       1.5%       3%

Conversion   2%               2%

Total (2.1 M) 33.5% 26.5% 2.5% 2% 17.5% 4.5% 3.5% 5.5% 5.5% 100%0%

62%

38%

Totals

TC assignment

Date

Type

Pre 1919-65 (64%) 1965-82 (25%) 1982-02 (11%)

Cavity Solid Non-trad.

Cavity | Solid

Cavity Solid Non-trad.

Cavity | Solid

Cavity

Timber | Trad.

Houses

Detached 6 2,1     6,7,17,18

  6, 18 2, 19 26 

17, 18  18%

Semi-detached 6 2, 1     6,7,17,18

  6, 18 2, 19 26 17, 18  21%

Terraced 6 1, 21 6 2 6,7,17,18

  6, 18 2, 19 26  17, 18 24%

Flats

Tenement 6 2, 1 6 2 6,7,17,18

  6, 18 2, 19 26 17, 18 23%

Four-in-a-block 6 1, 2 6 2 6,7,17,18

    2, 19     10%

Tower block 6   6       6, 18       3%

Conversion   1, 2               2%

Total (2.1 M) 33.5% 26.5% 2.5% 2% 17.5% 4.5% 3.5% 5.5% 5.5% 100%0%

62%

38%

Totals

EDEM application: national scale

Date

Type

Pre 1919-65 (64%) 1965-82 (25%) 1982-02 (11%)

Cavity Solid Non-trad.

Cavity | Solid

Cavity Solid Non-trad.

Cavity | Solid

Cavity

Timber | Trad.

Houses

Detached 4% 5%     4%   0.5% 0.5% 2% 

2% 

18%

Semi-detached 8% 5%     4%   0.5% 0.5% 1.5% 1.5  21%

Terraced 8.5% 3.5% 0.5 0.5% 6%   1.5% 1.5% 1%  1% 24%

Flats

Tenement 6% 9% 1% 1% 3%   0.5% 0.5% 1% 1% 23%

Four-in-a-block 6% 2% 0.5% 0.5% 0.5%     0.5%     10%

Tower block 1%   0.5%       1.5%       3%

Conversion   2%               2%

Total (2.1 M) 33.5% 26.5% 2.5% 2% 17.5% 4.5% 3.5% 5.5% 5.5% 100%0%

62%

38%

Totals

TC assignment

Date

Type

Pre 1919-65 (64%) 1965-82 (25%) 1982-02 (11%)

Cavity Solid Non-trad.

Cavity | Solid

Cavity Solid Non-trad.

Cavity | Solid

Cavity

Timber | Trad.

Houses

Detached 6 2,1     6,7,17,18

  6, 18 2, 19 26 

17, 18  18%

Semi-detached 6 2, 1     6,7,17,18

  6, 18 2, 19 26 17, 18  21%

Terraced 6 1, 21 6 2 6,7,17,18

  6, 18 2, 19 26  17, 18 24%

Flats

Tenement 6 2, 1 6 2 6,7,17,18

  6, 18 2, 19 26 17, 18 23%

Four-in-a-block 6 1, 2 6 2 6,7,17,18

    2, 19     10%

Tower block 6   6       6, 18       3%

Conversion   1, 2               2%

Total (2.1 M) 33.5% 26.5% 2.5% 2% 17.5% 4.5% 3.5% 5.5% 5.5% 100%0%

62%

38%

Totals

EDEM in use

Current stock maps to 8 TCs: - TC6 - TC2 - TC1 - TC7 - TC17 - TC18 - TC19

TC Description % of stock Number of

dwellings

Floor area (m2)

Annual heating demand

(kWh/m2)

1 Solid wall, high thermal mass, large windows, poor insulation and large air change rate

11.5 261,970 22,461,000 90

2 Solid wall, high thermal mass, standard windows, poor insulation and large air change rate

16.5 375,870 31,778,000 87

6 Cavity wall, outer thermal mass, standard windows, poor insulation and large air change rate

42 956,760 83,283,000 75

7 Cavity wall, inner thermal mass, large windows, standard insulation and large air change rate

7.25 165,155 15,934,000 73

17 Cavity wall, inner thermal mass, standard windows, standard insulation and standard air change rate

8.25 187,935 18,087,000 47

18 Cavity wall, outer thermal mass, standard windows, standard insulation and standard air change rate

11 250,580 23,810,000 47

19 Solid wall, standard thermal mass, standard windows, standard insulation and standard air change rate

2.5 56,950 5,159,000 46

26 Timber wall, outer thermal mass, standard windows, high insulation and standard air change rate

1 22,780 2,596,000 26

Upgradestrategy

ExistingTC

% of stock

% of annual heating demand

Improvement NewTC

National heating demand

reduction (TWh) (%)

TC6

TC11

42 43 Air tightness to high standards

TC11 0.67 4.6

Insulation to standard levels

TC18 2.2 15.5

TC2 16.5 19 Standard levels of draught proofing and insulation

TC19 1.3 9

TC1 11.5 14 High levels of draught proofing; standard levels of insulation

TC21 1.2 8.7

TC7 7.25 8 High levels of draught proofing and insulation

TC28 1 7

TC17 & TC18

19.25 13.5 High levels of draught proofing

TC22 0.7 5

High levels of insulation

TC24 0.9 6

High levels of draught proofing and insulation

TC30 1.6 11

TC19 2.5 1.5 High levels of draught proofing; standard levels of insulation

TC21 0.06 0.4

TC upgrades may be phased:

- TC6 to TC11 then to TC18

- TC18 to TC22/ TC24 then to TC30

12 TC relocations examined:• 1 to 16 and 21• 2 to 19• 6 to 11, 18 and 30• 7 to 28• 17 to 22 and 24• 18 to 30• 19 to 21

5 relocations gave highest potential for space heating energy savings:

• 1 to 21 (62%)• 2 to 19 (48%)• 6 to 30 (90%)• 7 to 28 (86%)• 18 to 30 (80%)

Upgradestrategy

Space heating impact, detached houses

Build period Construction

% of total stock

Generic TC

Total floor area (m2)

Net heating energy demand

(GWh /yr)

Heating energy saving

potential

New TC category

with energy saving

Net heating demand with energy saving

measures (GWh /yr)

Net heating energy saved

(GWh /yr)

Cavity wall 4 6 11,844,000 896 45% 11, 18, 30 492.8 403.2

Solid wall 5 1 14,805,000 1,322.4 45% 16, 21 727.3 595.1

Pre 1919-65

2 19

Cavity wall 4 6 11,844,000 710.6 75% 11, 18, 30 177.7 533.0

7 28

17 22, 24

18 30

Non-Traditional 0.5 6 1,480,500 88.9 85% 11, 18, 30 13.3 75.6

Cavity wall 18 30

Non-Traditional 0.5 2 1,480,000 88.9 37% 19 56.0 32.9

1965-1982

Solid wall 19

Cavity wall - Timber

2 26 5,922,000 154.2 55% 27 69.4 84.9

Cavity wall - Traditional 2 17 5,922,000 273.0 67% 22, 24 90.1 182.9

1982-2002

18 30

Total 18 53,297,500 3,544 1,626.6 1,917.7

Overall outcome: TC 6 to 30 for detached house

improvement

advice

EDEM application: regional scale

Number of commercial wind turbines required to offset emissions from South Ayrshire Council Housing Stock (based on the

proposed Whitelees wind farm, Eaglesham)

1715

12 11

8 8 7 7

3

upgrade scenario

turb

ines

(10

0m)

South Ayrshire Council Housing Stock (7876 dwellings) Carbon Footprint Projection

0.0

1.0

2.0

3.0

4.0

5.0

6.0

upgrade scenario

ca

rbo

n f

oo

tpri

nt

pe

r d

we

llin

g (

T C

O2

pa

)

ESP-r system used to formulate EDEM for domestic sector upgrade appraisal.

The approach is widely applicable because the underlying TCs cover all possibilities, present and future.

EDEM is available under an Open Source license.

EDEM has been applied at national and regional levels. In the former case (i.e. for Scotland 14.5 TWh/y):

Conclusions

Phase 1 (TC6, TC2 & TC1) - 4.7 TWh/y (32.4%) & 1.8 MT CO2

+Phase 2 (TC7) - 5.7 TWh/y (39.3%) & 2.2 MT CO2

+Phase 3 (TC17 & TC18) - 7.3 TWh/y (50.3%) & 2.8 MT CO2

+End of programme (TC19) - 7.6 TWh/y (52.4%) & 2.8 MT CO2