John Riley & Jack Hulme BRE 29 th February 2012 TABULA European Building Typologies Characterisation of dwellings in the UK determining the potential for enhanced energy efficiency Part of the BRE Trust
Structure of presentation Objectives Stock typology Progress to-date What s achievable? The scale of the task Challenges
UK Carbon Emissions Domestic, 27% (UK wide) Lighting, appliances and cooking 27% Agriculture etc. 1% Public 4% Business ~39% Emissions from the use of electricity and heating fuels by households account for 27% of the UK s total, making 148.5 MtCO 2 Space and water heating 73% 73% of household emissions arise from space and water heating, and 27% from lighting, appliances and cooking Source: www.occ.gov.uk Transport 29%
To consider the stock we need to simplify Whole stock 26,000,000 dwellings Each is different National survey 25,000 sample survey Nationally representative Archetypes 40 archetypes Average charactertistics of each type
Developing typologies All dwellings House Flat Detached Attached Converted Purpose built Semidetached Terrace High rise Low rise
Stock typology - Stock characteristics Part of the BRE Trust
Developing typologies BRE use two mechanisms for describing the stock ahead of improvement (or any other) modelling 1) Archetype approach 2) Housing Survey data approach
The archetype method Method 1: Archetype method Development of typical dwelling plans and descriptions for limited number of types. Layout and built form Description of key metrics Dimensions Energy efficiency characteristics This is followed by simulation of improvements onto these specific types
Archetype approach Using archetypes in this way is simplification of reality Beneath each type is variability Size Condition Energy efficiency etc. Concentrating on a single stereotype can be an oversimplification Where this variability is important (typically stock level modelling) use another technique
Housing Survey data approach Method 2: Use Housing Survey data directly Run models using 25,000+ records to allow more resolution and acknowledgement of the underlying variability Distribution of dimensions Distribution of dwelling condition Distribution of insulation Allows us to split the results of data by numerous factors (household type, tenure, income of household) As well as by classical typology variables of dwelling type and age. BUT data more complex to work with, to interpret is a conceptual leap for those more used to archetype approach. Still a simplification (essentially 20,000+ archetypes)
For any particular property type...... Number of occupants Insula'on levels Wall area Variation in input parameters from underlying data. We represent this variation by running thousands of cases for each type. Calculation of energy use y = y(x 1, x 2, x 3...x n ) Final distribu'on of energy use Variation in output produced mirrors underlying variability in the stock
Measuring improvements to energy efficiency Part of the BRE Trust
The scale of the task for England Mean SAP rating 54 53 52 51 50 49 48 47 46 45 44 43 42 41 Average SAP rating 1996-2009
Progress to-date % as a proportion of dwellings with cavity walls 70 60 50 40 30 20 10 0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 owner occupied private rented local authority RSL all tenures
SAP by Dwelling Age Mean SAP 70 65 60 55 50 45 40 35 30 Pre 1919 1919-1944 1945-1964 1965-1980 Post 1980
SAP by Dwelling Type Mean SAP 65 60 55 50 45 40 35 30 End terrace Mid terrace Semi detached Detached Bungalow Converted flat Purpose built flat
Predicting change The potential Part of the BRE Trust
Market penetration of home energy-efficiency related measures 100% 90% Hot water tank insulation ETP Scenario 1 80% Draught proofing Scenario 2 70% Central heating Percentage of potential 60% 50% 40% Double glazing Condensing boilers (scenarios developed under the Market Transformation programme) 30% 20% 10% Loft insulation (any) Cavity wall insulation Ref 0% 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 Year
Example of an Energy Performance Certificate
Understanding the scale of the task EPC recommended energy efficiency measures (2009) size of applicable group (000s) number of dwellings that would benefit from the measure (000s) percentage of applicable group (%) low cost measures (less than 500) loft insulation 19,737 8,002 41 cavity wall insulation 15,441 6,152 40 hot water cylinder insulation 12,522 3,931 31 higher cost measures (more than 500) heating controls 19,627 6,563 33 boiler upgrade 19,431 13,415 69 storage heater upgrade 2,358 1,627 69 hot water cylinder thermostat 12,522 1,134 9 replacement warm air system 196 137 70 install biomass system 528 50 9
Potential improvements in energy efficiency (SAP) ratings, CO2 emissions and fuel costs by dwelling age, 2009 SAP (rating) current perfomance CO2 (tones/ year) cost ( / year) post-improvement SAP (rating) CO2 (tones/ year) cost ( / year) SAP inc. (rating) difference CO2 saving (tones/ year) cost saving ( / year) pre-1919 44.3 8.2 781 53.9 6.5 633 9.6 1.7 148 1919-44 48.1 6.7 650 60.0 5.0 496 11.9 1.7 154 1945-64 52.9 5.7 557 64.8 4.1 414 11.9 1.6 143 1965-80 55.7 5.2 519 67.1 3.8 387 11.4 1.4 132 1981-90 58.2 4.8 490 67.1 3.8 387 9.0 1.1 103 post 1990 67.2 3.9 408 72.5 3.3 346 5.3 0.6 62 all ages 53.1 6.0 588 63.3 4.6 458 10.3 1.4 130
The scale of the task for England Mean SAP rating 90 85 80 75 70 65 60 55 50 45 40 Average SAP rating 1996-2050
Reaching the 80% target by 2050 Need to include: Stock condition Decarbonisation of the power supply Low carbon heat Advances in technology Changes in occupant behaviour
Stock Characteristics & the reality for improving energy efficiency The Challenges for Retrofitting Part of the BRE Trust
Retrofitting Challenges Stock Condition
Hard to Treat stock Category of HTT Dwellings Included Dwellings not included Solid wall Off gas network No loft High rise flats Traditional 9 masonry Single leaf masonry > 9 walls Concrete walls Metal panelled walls Timber panelled walls Dwellings with no mains gas system present Dwellings surveyed as having no loft Dwellings with mansard, chalet or flat roofs built pre-1990 Dwellings with pre-1990 loft conversions Flats at least 6 storeys high Cavity walls that cannot be filled for technical reasons Dwellings with communal heating systems Dwellings with mansard, chalet or flat roofs built post-1990 Dwellings with post-1990 loft conversions
Hard to Treat stock Number of dwellings (000s) % of all dwellings % of Hard to Treat stock Hard To Treat? Yes 9,309 42 No 13,026 58 Total 22,335 100 Solid wall 6,526 29 70 Off gas network 3,095 14 33 No loft space 1,267 6 14 High rise flat 321 1 3
Summary - Typologies help us by: - Splitting the stock into manageable groups - Allow us to consider the stock as a whole - Energy efficiency progress can be tracked against these typologies - Good progress made but much to achieve - Important to always recognise the simplifications of your typologies - Real nature (and difficulties) in the stock can be hidden by simplistic methods - Recommend multiple approaches are developed to avoid this
John Riley & Jack Hulme BRE 29 th February 2012 TABULA European Building Typologies Characterisation of dwellings in the UK determining the potential for enhanced energy efficiency Part of the BRE Trust