The holistic approach for retrofit of buildings
Dr David Tetlow
Content 1.
Defining the problem and why retrofit is so important
2.
The current retrofit approach – its drivers and limitations
3.
4.
•
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
There’s a global PROBLEM…..
Climate Change – The International problem
60% reduction of 1990 Carbon Equivalent emissions by 2050
What is the UK’s Progress? 12
The majority of emissions from these are from
Emissions (MtCO2e)
10
Down 28%
8
buildings
Down 15% 6
4
2
0 Year
779 MtCO2e (1990) → 581 MtCO2e (2012) We’re doing… OK… sort of…
Little room to improve
There’s a big Challenge Existing Buildings‌ UK 2050 required Average Rating
Exist Today Yet to build
The facts of 2050 ~6 million solid walled dwellings... ... Of a ~26 million total
80
Actual UK average rating?....
80
55
MILLIONS to Retrofit
RETROFIT…..
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
The financial reality Zero Use
Target Use 80% Saving
M6
Renewables (PV, Heat Pumps, etc) Mech ventilation + Heat recovery Energy Storage (PCM, Hydrogen, etc) ............ ~£300 + 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
What is the best solution & how do we choose?...
(RdSAP) The current assessment method
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?...... ….You Assume….
Face Value Acceptance..
Ass-U-Me
…& Risk of Losses
Assumptions using fixed condition data....
Based on who using the house?
A very large ranges of cost, & very narrow typical savings...
What is the best solution??? Starting at a score of 58
(Dowson, Poole et al. Energy Policy 2012)
Is this one size fits all approach common sense?.â&#x20AC;Ś.
Case examplesâ&#x20AC;¦..
The UK HERB houses
Te r
ra ce
UK Stock
-D Sem i
Ter rac es
Two Terrace & Four Semi-detached
Semidetached
ProďŹ le of the UK Housing stock by age and type (Dowson, Poole et al. 2012)
UK majority built in this 100 year period
HERB UK house surveys As Built
Year 1900s
Characteristics Solid fuel Single glazing No wall insulation No loft insulation No 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)
1
2
Y N N 200 N 38%
Y Y N 300 N 13%
PROPERTY 3 4 Y Y N 170 N 71%
Y Y N 300 N 13%
5
6
Y N N 200 N 67%
Y Y N 160 N 88%
Why?
Government subsidies and imposed energy legislation
However: Cross Solution Impacts… …Some examples
Example 1 – Static Solutions - Windows
s Built
Year 1900s
Characteristics Solid fuel Single glazing No wall insulation No loft insulation No 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)
1
2
Y N N 200 N 38%
Y Y N 300 N 13%
PROPERTY 3 4 Y Y N 170 N 71%
Y Y N 300 N 13%
5
6
Y N N 200 N 67%
Y Y N 160 N 88%
A Modern solution for a traditionally constructed building
WHY? Repairing or upgrading weather worn building materials
Old rotten wooden windows are replaced with modern uPVC efficient versions due to Necessity ~ÂŁ3000-5000
Discomfort….
Structural Problems….
Loss of
Example 2 – Active solutions – Boiler Replacements PROPERTY
As Built
Year 1900s
Characteristics Solid fuel Single glazing No wall insulation No loft insulation No 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)
1
2
3
4
5
6
Y N N 200 N 38%
Y Y N 300 N 13%
Y Y N 170 N 71%
Y Y N 300 N 13%
Y N N 200 N 67%
Y Y N 160 N 88%
20-25kW Heating load
3-6kW Heating load
Loss of Further
(1) Boiler upgrade
(2) Insulation of external walls (£7000-12000)
Boiler Oversized = Loss of efficiency
Consequences of cross-solution impact £££
M3 Usage LOSSM5M3Energy M2 M1 M6
££ Load requirement to improve Internal comfort = Loss of efficiency
M2 M1
M5
How to avoid cross solution impact?... â&#x20AC;ŚApproach the problem in Context.
(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
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
Comparison?....
• • • • •
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, No 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.
So whereâ&#x20AC;&#x2122;s this going?....
1
3
1
Sensors can be expensive
2
Method for subjective data collection requires development
3
Communication is manual â&#x20AC;&#x201C; requires automation
4
Data for economic analysis manually imported â&#x20AC;&#x201C; requires automation
1
4
1
2
5 2 3
3
5 Methods for testing innovations in holistic
4
integration require development
2015
1990
25 Years
It is 35 years to 2050, the problems listed should be resolvable based on our history
Thank you For your attention David.tetlow@nottingham.ac.uk www.euroretrofit.com