Transcript Isabel Carmona

“Green Deal for Real” conference
25th September 2012
Guidance structure and knowledge
(A decision making toolkit?)
Isabel Carmona
e-mail:[email protected]
Contents
• Background:
Thinking about saving energy and carbon: TRIAGE system for EH
• Retrofit and Green Deal measures
STBA Responsible Retrofit
Developing guidance structure: Context dependencies
• Decisions, decisions
• People and behaviour
• Complexity and interactions
Current knowledge – future knowledge
• Way forward
Background to the Triage study
• Triage study 2009-2010 by William Bordass Associates
for English Heritage:
• Historic and traditional buildings will be required to play
their part in reducing national and global carbon
emissions.
• Enthusiasts are pushing for major energy upgrades to all
housing, some of which may prove to be ill advised.
• To improve understanding and insight: can we make
more explicit the trade-offs between energy and carbon
saving opportunity, technical risks and heritage risks?
• Is there a simple and communicable way of doing this?
Thinking about Saving energy and carbon:
it’s not just about heating and the fabric
• It is also as much a social as a technical enterprise.
Engaging people comes first (objectives), second (getting
things done) and third (habits and waste avoidance) ...
• Electricity is important, particularly in carbon terms and in
non-domestic buildings, but increasingly so in domestic.
• Demand can be reduced by individual behaviour,
it doesn’t always need technical interventions.
• Efficiency can be improved - sometimes radically, with
new equipment, some of which is equally well suited to
old as to new buildings.
• Energy supplies can be decarbonised, often with little or
no direct effect on the end-user building.
Multiplier effect:
ENGAGE PEOPLE … AND, for example:
1. Halve the demand
X
2. Double the efficiency
X
3. Halve the carbon in the supplies
and …
you’re down to one-eighth of the carbon
Step 1 can be more difficult in historic buildings, especially
for heating, but steps 2 and 3 remain.
The basic triage process
• Take a measure.
• Assess it for:
- Energy (and carbon) saving opportunity;
- Technical risk (e.g. of damp and decay);
- Heritage risk (to substance or appearance).
• Report each facet as traffic lights (see below).
• Reach an overall conclusion (and report in the same way).
TRIAGE KEY
FEASIBLE
TAKE CARE
AVOID
Triage:
From an example - one aspect at one stage in the
process only
F1
3.1a
OK to proceed
Take care
Avoid
FRONT ELEVATION - EXTERNAL WALL INSULATION OPTION
Energy saving
Reasonable
opportunity
3.1b
Technical risk
3.1c
Effect on
heritage
Uncertain
Overall conclusion - normally graded
as the worst of the three aspects above
F2
3.2a
3.2b
3.2c
Relatively expensive in
relation to effect
Take care about trapped
moisture
If done to one house only,
Unacceptable
it would destroy the
character of the terrace
Unless the whole terrace
INAPPROPRIATE
could be done
FRONT ELEVATION - INTERNAL WALL INSULATION OPTION
Energy saving
Reasonable
opportunity
Technical risk
Effect on
heritage
Overall conclusion - normally the
worst of the 3 aspects above
Uncertain
Tolerable
TAKE CARE
Comments
Relatively expensive in
relation to effect
Take care about trapped
moisture, joist ends and
returns
Possibly acceptable if
done with care
May merit further
investigation
The cornice will need moving
To a prototype an
Excel workbook, aimed at expert designers
Operating the triage system
• Analyse context - (to give an idea of what is possible)
• Identify options- (e.g. external or internal insulation)
• Use Triage system: assess likely performance of each item under
the three facets (technical opportunity, technical risk, heritage risk).
• Seek appropriate solutions: where everything is green.
• If some technical risk aspects of the final design are amber, you
should monitor and report the outcome, so that we can understand
what works and what doesn’t and make better decisions next time.
• Options in red may sometimes have potential if the context changes.
• Combine the options into appropriate packages (time/money filters).
TRIAGE KEY
FEASIBLE
TAKE CARE
AVOID
Retrofit and Green Deal Measures
• January to March 2012 – STBA Report on Responsible
Retrofit of Traditional buildings looked at:
• Existing research and guidance for traditional buildings
energy performance as existing and retrofitted buildings
• Providing a guidance structure to collate the best
practice research and guidance (and ideas for a decision
tool – upgrade analysis)
Gaps
Building performance data mainly based on modelling - not
corresponding to actual use data
Heat loss of walls – gap between theoretical assumptions
and measured reality
Physics of moisture behaviour within fabric not thoroughly
understood and accuracy modelling of moisture uncertain
Little on floors and roofs performance
Value of secondary glazing found on research not reflected
in guidance
Gaps also on thermal bridging detailing and practice and on
air tightness
Uncertainty on ventilation requirements needed by
traditional buildings and great uncertainty on the
performance of MVHR (poor design, installation and
maintenance)
Little on lighting, overheating, occupant interaction, user
health
Gaps on links between
• Ventilation to health of occupants
• Retrofit to thermal comfort
• Lifestyle to energy use and the possible rebound effects
of retrofit
• Thermal mass to energy and comfort
• Energy conservation and building conservation
(particularly repair and maintenance)
• Energy efficiency and heritage values
• Energy efficiency and community
Guidance Structure
– Learning based approach, based on a guidance structure:
iterative, open, contextual, systemic, holistic, with feedback
mechanisms
– Linked to public knowledge centre to guide research,
training, and to log, analyse and integrate feedback
Upgrade measures
A. Changes to fabric: normally this would include improving the
insulation properties of the building elements. It can also mean
making building features operational (for instance recovering the
use of timber shutters).
B. Changes to services and energy source: improving the
efficiency of the engineering systems and decarbonising supply
C. Behavioural changes: improving the way people interact with
the building by designing better interfaces or increasing the
involvement of users and maintenance staff
Ideally the upgrade measure should achieve the desired saving of
energy without creating a technical risk to the building or the occupant
whilst maintaining or improving the heritage value of the building
External Wall Insulation example
Contextual factors
A. Heritage value – and any specific planning requirements - listed building or in a
conservation area?
B. Ownership, tenure and income – who are the beneficiaries?
C. Number of similar units – would the measure be easier to implement in a group of
properties?
D. Fabric sensitivity – fragile or robust to change? Extreme caution is needed.
E. State of repair – any repairs needed before intervention? Usable features?
F. Exposure – to the rain and wind – will determine whether some measures are
suitable or not
G. Current energy performance – is there room for improvement through behaviour,
control and management first; or is the building operated frugally, making the
proposed measures less economic?
H. Locality – is it an isolated building, semi-detached or terrace, a block of flats, or a
street?
I. Community – is the property in a isolated rural location with plenty of space around,
in a suburb, or tight onto the street in an urban environment?
J. Date of property – this will determine the materials and techniques used in
construction. Materials expertise needed? Previous changes?
K. Interest and involvement of the owner and occupier in design and in
operation – what is their level of interest and motivation? Is a robust (fit and forget)
approach needed, or can measures that require more maintenance or user
involvement be included?
Contextual factors
A. Heritage value – and any specific planning requirements - listed building or in a
conservation area?
B. Ownership, tenure and income – who are the beneficiaries?
C. Number of similar units – would the measure be easier to implement in a group of
properties?
D. Fabric sensitivity – fragile or robust to change? Extreme caution is needed.
E. State of repair – any repairs needed before intervention? Usable features?
F. Exposure – to the rain and wind – will determine whether some measures are
suitable or not
G. Current energy performance – is there room for improvement through behaviour,
control and management first; or is the building operated frugally, making the
proposed measures less economic?
H. Locality – is it an isolated building, semi-detached or terrace, a block of flats, or a
street?
I. Community – is the property in a isolated rural location with plenty of space around,
in a suburb, or tight onto the street in an urban environment?
J. Date of property – this will determine the materials and techniques used in
construction. Materials expertise needed? Previous changes?
K. Interest and involvement of the owner and occupier in design and in
operation – what is their level of interest and motivation? Is a robust (fit and forget)
approach needed, or can measures that require more maintenance or user
involvement be included?
Internal Wall Insulation example
Moisture content and orientation
Internal Wall Insulation example
Current research
Internal Wall Insulation example
Contextual factors
A. Heritage value – and any specific planning requirements - listed building or in a
conservation area?
B. Ownership, tenure and income – who are the beneficiaries?
C. Number of similar units – would the measure be easier to implement in a group of
properties?
D. Fabric sensitivity – fragile or robust to change? Extreme caution is needed.
E. State of repair – any repairs needed before intervention? Usable features?
F. Exposure – to the rain and wind – will determine whether some measures are
suitable or not
G. Current energy performance – is there room for improvement through behaviour,
control and management first; or is the building operated frugally, making the
proposed measures less economic?
H. Locality – is it an isolated building, semi-detached or terrace, a block of flats, or a
street?
I. Community – is the property in a isolated rural location with plenty of space around,
in a suburb, or tight onto the street in an urban environment?
J. Date of property – this will determine the materials and techniques used in
construction. Materials expertise needed? Previous changes?
K. Interest and involvement of the owner and occupier in design and in
operation – what is their level of interest and motivation? Is a robust (fit and forget)
approach needed, or can measures that require more maintenance or user
involvement be included?
Internal Wall Insulation example
Decisions Decisions
Internal Wall Insulation example
Energy Saving
Technical
User energy consumption –
assumed standard
Moisture risk for Location
(HIGH): Swansea
Heritage
No internal heritage
features assumed
Moisture risk for orientation (Medium):
Swansea N Wall
Less saving makes it
not viable for funding
• choose reduced insulation thickness: eg. 50mm
• model to EN15026 – confirm system suitable
• Energy Saving still warrants Green Deal funding?
CONSIDER:
Complexity?
Timing?
Less saving but still
viable for funding
•
•
•
•
•
Develop Insulation and thermal bridging detailing
In construction quality check (thermal imaging)
Build in monitoring (moisture monitoring protocol)
State fabric maintenance checks
Consider in-use restrictions
• Watching brief on moisture – feedback monitoring
results
• Report actual U-value achieved
Contextual factors
A. Heritage value – and any specific planning requirements - listed building or in a
conservation area?
B. Ownership, tenure and income – who are the beneficiaries?
C. Number of similar units – would the measure be easier to implement in a group of
properties?
D. Fabric sensitivity – fragile or robust to change? Extreme caution is needed.
E. State of repair – any repairs needed before intervention? Usable features?
F. Exposure – to the rain and wind – will determine whether some measures are
suitable or not
G. Current energy performance – is there room for improvement through behaviour,
control and management first; or is the building operated frugally, making the
proposed measures less economic?
H. Locality – is it an isolated building, semi-detached or terrace, a block of flats, or a
street?
I. Community – is the property in a isolated rural location with plenty of space around,
in a suburb, or tight onto the street in an urban environment?
J. Date of property – this will determine the materials and techniques used in
construction. Materials expertise needed? Previous changes?
K. Interest and involvement of the owner and occupier in design and in
operation – what is their level of interest and motivation? Is a robust (fit and forget)
approach needed, or can measures that require more maintenance or user
involvement be included?
People and Behaviour
Energy Use
Parity Projects analysis of 40 homes in London, built within 5 years of each
other around 1900, within one mile of each other, unusual houses removed
People and Behaviour
Other issues:
Thermal Comfort – low energy use but low comfort?
Health – air quality (ventilation)
Lifestyle practices – ventilation customs, drying clothes,
clothing customs, cultural variations.
We need to understand before changing:
Work with the users and check what level of complexity is
possible (fit and forget or highly managed?)
Clear communication and managing expectations
Improving User motivation
Contextual factors
A. Heritage value – and any specific planning requirements - listed building or in a
conservation area?
B. Ownership, tenure and income – who are the beneficiaries?
C. Number of similar units – would the measure be easier to implement in a group of
properties?
D. Fabric sensitivity – fragile or robust to change? Extreme caution is needed.
E. State of repair – any repairs needed before intervention? Usable features?
F. Exposure – to the rain and wind – will determine whether some measures are
suitable or not
G. Current energy performance – is there room for improvement through behaviour,
control and management first; or is the building operated frugally, making the
proposed measures less economic?
H. Locality – is it an isolated building, semi-detached or terrace, a block of flats, or a
street?
I. Community – is the property in a isolated rural location with plenty of space around,
in a suburb, or tight onto the street in an urban environment?
J. Date of property – this will determine the materials and techniques used in
construction. Materials expertise needed? Previous changes?
K. Interest and involvement of the owner and occupier in design and in
operation – what is their level of interest and motivation? Is a robust (fit and forget)
approach needed, or can measures that require more maintenance or user
involvement be included?
People and Behaviour
•
•
sheer interest and knowledge can make a success of a situation that might
otherwise be risky; but
if occupants are careless or lacking in interest, many good intentions could easily be
undermined
Assessing how involved users are and what is their knowledge and motivation can
be used to help judging technical risk and the need for robust design and clarity.
Complexity and interactions
There is no single answer – there are great context differences between situations,
but understanding the context will help to suggest suitable solutions.
There is uncertainty of the data and outcome - but we are learning
Interactions are complex: it is a thinking process of taking risks knowingly and
allowing for learning from the outcome.
You might want to increase airtightness (draught proofing and/or new windows), but need to consider
ventilation strategy – you find out that complex user maintenance is not possible or uncertain, so
decide to retain a more natural ventilation solution and don’t make house too air tight, the building has
character anyway and the old windows are fine (even if single glazed) so in the end you repair them
and draughtproof them but keep an eye on air quality (monitor CO2), informing the user about opening
windows if too hot (but switch heating off first!).
Current knowledge gaps: feedback and monitoring should help to fill
those gaps and inform our future knowledge
Way forward
• Guidance structure to make decisions considering
context and user and aware of the risks
• What are the risks (known or suspected)
• How to minimise them (if worth taking) – checks, quality
control, maintenance needs
• What to monitor and watch out for and what feedback is
needed
• Building up and collecting knowledge