Energy and Carbon Performance of Housing: Upgrade Analysis, Energy Labelling and National Policy Development Joe Clarke, Cameron Johnstone, Jae-min Kim, Paul Tuohy Energy 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 CO 2 ) 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 (/m 2 ) 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 possible dwellings poor insulation low mass small windows leaky … well insulated high internal mass large windows well sealed … discrete designs 6,480 simulated models 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.

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 low med frugal ave profl high std future high no med profl frugal ave high low med h-m UKCIP m-lavelow 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

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 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 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/ /0/2/2/ /0/1/1/ /0/0/0/ /0/0/1/ /0/1/2/ /1/1/0/ /1/0/1/ /0/0/0/ /0/0/1/ /0/1/2/ /0/2/1/ /0/2/0/ /0/1/1/ /1/2/0/ /2/2/2/ /1/1/0/ /1/1/2/ /1/2/2/ /1/1/1/ /1/2/2/ /1/1/0/ /2/1/2/ /2/1/0/ /1/0/1/ /2/0/2/ /2/0/2/ /2/1/0/ /2/0/0/ /2/1/2/ E = a θ + b R d + c R f + dV + e θ R d + f θ R f + g θ V + h R d R f + i R d V + j R f 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 (kWh m -2 y -1 ) TC model TC heating (kWh m -2 y -1 ) % difference #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)

Certificate and improvement advice Individual dwelling statement EDEM: application scale Individual dwelling EPBD rating and action plan generation EDEM Stock rating and upgrade strategy appraisal Scottish house condition survey CONTEXT policy, climate, fuel, demographics, economics

EDEM in use

EDEM in use: emissions label high insulation level:tight air leakage:new heating system:

current rating improved rating ENERGY CERTIFICATE improvement advice EDEM in use: energy certificate household questionnaire

EDEM application: national scale Date Type Pre (64%) (25%) (11%) CavitySolidNon-trad. Cavity | Solid CavitySolidNon-trad. Cavity | Solid Cavity Timber | Trad. Houses Detached4%5% 4% 0.5% 2% 2% 18% Semi-detached8%5% 4% 0.5% 1.5%1.5 21% Terraced8.5%3.5%0.50.5%6% 1.5% 1% 24% Flats Tenement6%9%1% 3% 0.5% 1% 23% Four-in-a-block6%2% 0.5% 10% Tower block1% 0.5% 1.5% 3% Conversion 2% Total (2.1 M)33.5% 26.5%2.5% 2% 17.5% 4.5%3.5%5.5% 100%0% 62% 38% Totals

TC assignment Date Type Pre (64%) (25%) (11%) CavitySolidNon-trad. Cavity | Solid CavitySolidNon-trad. Cavity | Solid Cavity Timber | Trad. Houses Detached62,1 6,7,17, 18 6, 182, , 18 18% Semi-detached62, 1 6,7,17, 18 6, 182, , 18 21% Terraced61, ,7,17, 18 6, 182, , 18 24% Flats Tenement62, 162 6,7,17, 18 6, 182, , 18 23% Four-in-a-block61, 262 6,7,17, 18 2, 19 10% Tower block6 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% 100%0% 62% 38% Totals

EDEM application: national scale Date Type Pre (64%) (25%) (11%) CavitySolidNon-trad. Cavity | Solid CavitySolidNon-trad. Cavity | Solid Cavity Timber | Trad. Houses Detached4%5% 4% 0.5% 2% 2% 18% Semi-detached8%5% 4% 0.5% 1.5%1.5 21% Terraced8.5%3.5%0.50.5%6% 1.5% 1% 24% Flats Tenement6%9%1% 3% 0.5% 1% 23% Four-in-a-block6%2% 0.5% 10% Tower block1% 0.5% 1.5% 3% Conversion 2% Total (2.1 M)33.5% 26.5%2.5% 2% 17.5% 4.5%3.5%5.5% 100%0% 62% 38% Totals

TC assignment Date Type Pre (64%) (25%) (11%) CavitySolidNon-trad. Cavity | Solid CavitySolidNon-trad. Cavity | Solid Cavity Timber | Trad. Houses Detached62,1 6,7,17, 18 6, 182, , 18 18% Semi-detached62, 1 6,7,17, 18 6, 182, , 18 21% Terraced61, ,7,17, 18 6, 182, , 18 24% Flats Tenement62, 162 6,7,17, 18 6, 182, , 18 23% Four-in-a-block61, 262 6,7,17, 18 2, 19 10% Tower block6 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% 100%0% 62% 38% Totals

EDEM in use

Current stock maps to 8 TCs: - TC6 - TC2 - TC1 - TC7 - TC17 - TC18 - TC19 TCDescription% of stockNumber of dwellings Floor area (m 2 ) Annual heating demand (kWh/m 2 ) 1 Solid wall, high thermal mass, large windows, poor insulation and large air change rate ,97022,461, Solid wall, high thermal mass, standard windows, poor insulation and large air change rate ,87031,778, Cavity wall, outer thermal mass, standard windows, poor insulation and large air change rate 42956,76083,283, Cavity wall, inner thermal mass, large windows, standard insulation and large air change rate ,15515,934, Cavity wall, inner thermal mass, standard windows, standard insulation and standard air change rate ,93518,087, Cavity wall, outer thermal mass, standard windows, standard insulation and standard air change rate 11250,58023,810, Solid wall, standard thermal mass, standard windows, standard insulation and standard air change rate 2.556,9505,159, Timber wall, outer thermal mass, standard windows, high insulation and standard air change rate 122,7802,596,00026 Upgrade strategy

Existing TC % of stock % of annual heating demand ImprovementNew TC National heating demand reduction (TWh) (%) TC6 TC Air tightness to high standards TC Insulation to standard levels TC TC Standard levels of draught proofing and insulation TC TC High levels of draught proofing; standard levels of insulation TC TC77.258High levels of draught proofing and insulation TC2817 TC17 & TC High levels of draught proofing TC High levels of insulation TC High levels of draught proofing and insulation TC TC High levels of draught proofing; standard levels of insulation TC 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 to 22 and to 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%) Upgrade strategy

Space heating impact, detached houses

Overall outcome: TC 6 to 30 for detached house

improvement advice EDEM application: regional scale

 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 CO 2 + Phase 2 (TC7) TWh/y (39.3%) & 2.2 MT CO 2 + Phase 3 (TC17 & TC18) -7.3 TWh/y (50.3%) & 2.8 MT CO 2 + End of programme (TC19) -7.6 TWh/y (52.4%) & 2.8 MT CO 2