The holistic approach for retrofit of buildings. Dr David Tetlow

Transcription

1 The holistic approach for retrofit of buildings Dr David Tetlow

2 Content 1. Defining the problem and why retrofit is so important 2. The current retrofit approach its drivers and limitations Overview of factors that affect its uptake Example cases The holistic retrofit approach its innovation over the existing system The rationale Step by Step Comparison of approaches and future challenges

3 There s a global PROBLEM..

4 Climate Change The International problem 60% reduction of 1990 Carbon Equivalent emissions by 2050

5 What is the UK s Progress? 12 The majority of emissions from these are from Emissions (MtCO2e) 10 Down 28% 8 buildings Down 15% ear 779 MtCO2e (1990) 581 MtCO2e (2012) We re doing OK sort of Little room to improve

6 There s a big Challenge Existing Buildings UK 2050 required Average Rating Exist Today et to build The facts of 2050 ~6 million solid walled dwellings Of a ~26 million total 80

7 Actual UK average rating? MILLIOS to Retrofit

8 RETROFIT..

9 Home energy retrofit is done to solve a Problem Acute problems Immediate Action Old lowefficiency central heating Leaks in building structure requiring repair Chronic problems Limited Action Cold & poorly maintained external walls Old & leaking windows Level of action is dependant on peoples perceptions & considerations

10 The financial reality Zero Use Target Use 80% Saving M6 Renewables (PV, Heat Pumps, etc) Mech ventilation + Heat recovery Energy Storage (PCM, Hydrogen, etc)... ~ install cost per 1% saved energy..? Current Use M5M3Energy M3 Usage M2 M1 High Resistance Windows Solid Wall Insulation ~ 275 install cost per 1% saved energy ~ 200 install cost per 1% saved energy M2 M1 Loft Insulation &/or Boiler upgrade M5 Low energy lighting < 50 install cost per 1% saved energy

11 What is the best solution & how do we choose?...

12 (RdSAP) The current assessment method

13

14 4-6 weeks < 24 Hours Building Survey Pre-Retrofit Analysis Dimensions, Location, Site, Constructions, Services, Layout, Air Tightness, Appliances RdSAP Calculation Process Retrofit Recommendations + Possible Savings Many Assumptions made Retrofit Actions Taken Leading to s Spent & Savings?....ou Assume. Face Value Acceptance.. Ass-U-Me & Risk of Losses

15 Assumptions using fixed condition data... Based on who using the house? A very large ranges of cost, & very narrow typical savings...

16 What is the best solution??? Starting at a score of 58 (Dowson, Poole et al. Energy Policy 2012)

17 Is this one size fits all approach common sense?..

18 Case examples..

19 The UK HERB houses Te r ra ce UK Stock -D Sem i Ter rac es Two Terrace & Four Semi-detached Semidetached Profile of the UK Housing stock by age and type (Dowson, Poole et al. 2012) UK majority built in this 100 year period

20 HERB UK house surveys As Built ear 1900s Characteristics Solid fuel Single glazing o wall insulation o loft insulation o floor insulation Current 2013 Change of fuel & boiler change (possibly A rated) Double glazing CWI/EWI/IWI 270mm mineral quilt loft insulation Floor insulation Low energy lighting (CFLs) % % PROPERT % % % % Why? Government subsidies and imposed energy legislation

21 However: Cross Solution Impacts Some examples

22 Example 1 Static Solutions - Windows s Built ear 1900s Characteristics Solid fuel Single glazing o wall insulation o loft insulation o floor insulation urrent 2013 Change of fuel & boiler change (possibly A rated) Double glazing CWI/EWI/IWI 270mm mineral quilt loft insulation Floor insulation Low energy lighting (CFLs) % % PROPERT % % % % A Modern solution for a traditionally constructed building

23 WH? Repairing or upgrading weather worn building materials Old rotten wooden windows are replaced with modern upvc efficient versions due to ecessity ~

24 Discomfort. Structural Problems. Loss of

25 Example 2 Active solutions Boiler Replacements PROPERT As Built ear 1900s Characteristics Solid fuel Single glazing o wall insulation o loft insulation o floor insulation Current 2013 Change of fuel & boiler change (possibly A rated) Double glazing CWI/EWI/IWI 270mm mineral quilt loft insulation Floor insulation Low energy lighting (CFLs) % % % % % %

26 20-25kW Heating load 3-6kW Heating load Loss of Further (1) Boiler upgrade (2) Insulation of external walls ( ) Boiler Oversized = Loss of efficiency

27 Consequences of cross-solution impact M3 Usage LOSSM5M3Energy M2 M1 M6 Load requirement to improve Internal comfort = Loss of efficiency M2 M1 M5

28 How to avoid cross solution impact?... Approach the problem in Context.

29 (1) Building dimensions (2) Climate (3) Building type (5) Building Services (7) Building Site Impacts (9) Appliances (11) Energy Prices (13). (4) Building Orientation (6) Environmental Controls (8) Occupant behaviour (10) Primary Energy Sources (12) Occupant Preferences Analyse the system as a Whole hence holistic

30 6-12 Months Building Survey Dimensions, Location, Site, Constructions, Services, Layout, Air Tightness, Appliances 4-6 weeks Pre-Post Retrofit Analysis Energy Simulations 6-12 Months Physical Monitoring Retrofit Plan + Actions Mains Gas, Mains Electric, Appliances, Climate, Temperature, Humidity, Luminance Physical Monitoring Subjective Monitoring Mains Gas, Mains Electric, Climate, Temperature, Humidity, Luminance Appliance usage, Heating usage, Comfort Perception, General Wellbeing Comfort Simulations Economic Analysis Subjective Monitoring Appliance usage, Heating usage, Cooking, Comfort Perception, General Wellbeing Retrofit Technology Solution Library Accuracy Feedback Analysis + System Update ROI Survey Gas & Electric Savings, Renewables Income, Resident Comfort & Wellbeing

31 Comparison?...

32 Existing Method Holistic Method Advantages Advantages Quick, Based on Solid-Science (i.e. the BRE), Government Approved, Low Cost, Can be applied to large scale developments when funding is available. Disadvantages Disadvantages Uses many Assumptions, Science used is limited, Bases calculations on Abstract Data, Open to Human Error, Provides only Typical Savings, Gives no sense of certainty to resident, o recognition of Cross-Solution Impact, Subjective feedback used for its updates, Resident financial commitment based on faith. Based on measured Physical Data, Accurate, Gives a range of solutions for resident needs, Aims to improve Wellbeing of residents, Flexible to changing economic conditions, Evolves using physical data feedback, Provides Certainty for investment, Makes the industry more Accountable. Underdeveloped Requires time-investment, Currently is expensive, Requires technology development, Requires software development, Has not been proven to function, Requires use of sensitive data.

33 So where s this going?...

34 1 3 1 Sensors can be expensive 2 Method for subjective data collection requires development 3 Communication is manual requires automation 4 Data for economic analysis manually imported requires automation Methods for testing innovations in holistic 4 integration require development ears It is 35 years to 2050, the problems listed should be resolvable based on our history

35 Thank you For your attention