Building Performance Measurement
Thursday 2nd August 2012
COMBINED RESULTS from WORKSHOPS
1
Background
The UK Government‟s target of
an 80% reduction of CO2 emissions by
2050 is a challenging one. With around
45% of total emissions coming from
buildings alone, the construction sector
is under increasing pressure to deliver
more
energy
efficient
buildings.
Currently, there are ~26 million homes
in the UK and it has been estimated
that around 70-80% of the dwellings
we will occupy in 2050 have already
been built. This places great emphasis
on retrofit and the delivery of new
highly energy efficient buildings.
By 2016 all new builds will have
to be zero carbon. On top of this, to
achieve the 80% reductions it has been
suggested that we would not only need
to build and deliver all new housing
stock at zero carbon, but retrofit an
existing „older‟ building nearly every
minute up to 2050.
The scale of the challenge in
reducing fossil fuel dependency in the
built environment is vast. In terms of
research and understanding the BPE
sector is still in its early stages. This
provides significant opportunity for the
industry as a whole to improve on and
develop new methods, tools and
technologies for Building Performance
Evaluation (BPE).
“A pessimist sees the difficulty in every
opportunity; an optimist sees the
opportunity in every difficulty”
Winston Churchill
2
Overview
Scope
Buildings are complex systems, therefore
truly understanding their performance is difficult.
It is well documented that gaps in designed
performance and as built performance exist. A
comprehensive report by the Joseph Rowntree
Foundation in conjunction with Leeds Metropolitan
University provides a clear example of this,
showing a disparity of around 75% between
designed and actual performance [1].
There is a clear need to bridge the gap
between as designed/ expected performance and
that actually delivered. The Technology Strategy
Board has led the Building Performance Evaluation
Programme to support this aim through
innovation and competitiveness. £8m worth of
funding is being used to finance over 100 building
performance evaluation studies, both on domestic
and non-domestic buildings. The aim of the
programme is to use the long term learning
gained from across the studies to help deliver
more efficient, better performing buildings.
This wider learning feeds directly into an
observation made by the Royal Academy of
Engineering in a recent report [2] highlighting that
there is a lack of well-informed, strategic design
decisions being made and therefore an
experimental approach to assessing building
performance. An approach based on synthesis,
rigorous analysis, testing and measurement of
outcomes is needed.
Furthermore, in truly understanding the
performance of buildings; confidence is needed in
the measurements made, models used and
analysis undertaken. The Measurement Network
(MN) managed by the National Physical
Laboratory in conjunction with the Modern Built
Environment (MBE) KTN and the Technology
Strategy Board (TSB) held a workshop looking at
the measurement challenges faced by the BPE
community and the direction needed to help solve
these.
The workshop was held on 2nd August
2012 at the TSB offices in Swindon. Time was
limited and therefore specific guidance was given
to focus the discussions.
Particular emphasis was placed on
understanding the measurement tools for BPE
that are available at present in terms of sensors
(and other technology) as well as those used to
interpret and model the data. Included in the
scope was a focus on understanding if these tools
are fit for purpose, what gaps/ deficiencies exist,
and developing potential solutions to fill these.
Particular items were omitted from the
scope given the short time frame allocated to the
workshop. Those items were SAP, SBEM, EPC,
DEC and Occupant Satisfaction/ Behaviour.
The following information is a lightly
edited version of the output from the five
breakout discussions. As far as possible it follows
the pattern of the workshops.
3
Workshop Outputs
Throughout the workshop there were a number of underlying themes and areas of discussion. The general
thoughts of the attendees are captured below.
Drivers
Cost is undoubtedly a key driver. How
much do we want to spend on measurements and
evaluations, how much do we want to impact
people‟s lives in carrying out measurements? The
number of measurements and evaluations
essentially could be limitless. Variables outside of
just strict measurements alone need to be
considered in conjunction.
Another key driver is the type of
measurement taken. Consideration needs to be
given regarding the collection of data - is it critical
to know, or would be nice to know? There also
needs to be consensus and confidence that the
right things are being measured at the right time,
with the right tool and comparisons are made in
the right way.
The strict measurement of energy
consumption alone is not enough, it needs to be
put in context – why, when, how – for it to be
meaningful. Once in context, how do we use this
information, validate it and accurately compare?
There are a number of drivers around
improving Feedback – in the short, medium and
long term. Systems could be in place to
continually monitor performance over the life time
of the building; however, there are associated
challenges around cost, ownership of equipment,
monitoring, ownership of data and so forth. This
model is used by the aerospace industry. Whether
this is a sensible option for the construction
industry is up for debate? Better feedback for the
users of buildings over and above the display
certificates would be beneficial - useful feedback
to users could help drive efficiency savings,
increase the desire to seek more sustainable
buildings and change behaviour.
Greater
understanding and inclusion of the building‟s
users may lead to more upward consumer
pressure on the delivery of buildings (similar to
the role of NABERS in Australia).
The nature of building ownership (privately
owned, rental, mass developer etc.) drives
interest in performance and all are different for
different reasons, it‟s not one size fits all.
Developing a clear chain of interest in building
performance
from
design,
construction,
commissioning through to the needs of the user
should be considered to achieve truly performing
buildings. Risk management plays a role, where
the risk is seen as performance. The key issue
here is who owns the risk and whose job is it to
manage it – especially in the long term?
New innovative business models are
needed, for example ones that reward
performance. Green Deal is a good start, but
more needs to be done given the tough targets
set out by government. New technologies need to
fit within the building system, rather than sit in
isolation
–
improving
feedback
and
interoperability.
4
What measurement tools for building performance do we have now?
Excluding SAP, SBEM, EPC, DEC and Occupant satisfaction
The grid below was used as a framework to stimulate ideas. Participants were asked to fill the gaps with the
technology and tools. The positioning of points in the table is not limiting, most things have relevance to
other boxes. Places are based on the context of discussion at the time. The first column provides phases in
which the tool would be used; the following two columns then highlight the type of tool.
Sensors, devices and technology
Building research and
development and
design
Hot boxes
Hot plates
Emissivity equipment
Heat metering
Data handling, modelling and
benchmarking
Asset rating
Benchmarking individual components against
usage and area
BMS
Climate and weather data
CO2 conversion factors
Finite Element Analysis, Karman-filter,
Statistical Learning etc modelling and
simulation
Modelling tools such as TAS, IES
Soft landings
Spread sheets and SQL home grown tools
Co-heating test
Thermal simulation
Validation and
delivery of buildings
Acoustics
Airtightness
Flaws in performance of composites
Heat metering
Heat flux
IAQ monitoring – temp., RH, CO2, NOx ., dust
ppm, dust mites, VOCs
Lighting levels
Moisture content of materials
Refrigerant
Smoke tests
Thermal imaging
Tracer gas tests
U-value testing
COBie
On-going
measurement in use
BMS
Climate and weather data
Local weather station (on building site)
BMS
Meters for
Soft landings
Heat
TM 22
DomEARM
Energy main and sub meters – e.g. for
Benchmarking individual components against
itemised billing, wired and wireless
Consumer monitors
usage and area
Spread sheets and SQL home grown tools
RH (capacitance and thermoplastic…)
Asset rating
Water
Smart meters
State monitoring (e.g. windows open/ close)
Occupant sensors – movement and numbers
Smart meters
5
Are these fit for purpose and what are the gaps?
General Discussion
There are well understood and reliable
technologies/ sensors for nearly all needs in BPE,
though a few gaps are identified (see following page).
Addressing the gaps and challenges is related to the
user having a clear and succinct business case, one
which justifies the implementation of a given solution.
This will determine if a clear technical basis exists for
the choice of sensors/ technology, the implementation
approach, and the use of the data. This provides
strength in the selection of fit-for purpose tools rather
than ones that are questionable.
Consideration needs to be given to system/
sensors interoperability and the integration/evaluation
of outputs.
Accuracy of off the shelf sensors isn't a problem
per se, it's the interoperability of them that may cause
the challenge (what's the level of noise associated with
them, will this affect results?). How do you know if the
sensors are failing or not performing to standard/
expectation? Data collection is difficult in domestic
buildings (in situ measurement is needed). There is
also the added issue around the inability to collect data
from current pay-as-you-go metres and other such like
devices.
There are major gaps in the capability of
modelling, simulation, analysis and reporting software,
bench-marking tools and industry processes used by
building managers. At present, home-grown reporting
and management tools are used which are technically
unsatisfactory, not traceable and are incapable of being
benchmarked even if there was a forum for such
benchmarking. There is the added issue of tools being
used to measure/ capture data of components they
were not designed for, therefore the data is
fundamentally wrong and the associated assumptions
are incorrect.
The „areas‟ on the following page were highlighted
by the group as particular gaps and deficiencies. Some
of the groups scored them, and they are ranked below
in descending order of importance
6
Area
Suggestion
Score
Ventilation
Better and more integrated measurement devices
14.6%
Legislation
Better tools needed to enable Regulations to be implemented
13.2%
Heat flow
Generic
Meters are inadequate. Water Heat Flow - how do you do it cheaply with minimal interference
(without impellers)
Tools for diagnostic purposes need to be separated between services, fabric and occupants and
for unregulated emissions by different components in buildings (this will begin to matter more
as regulated emissions decline)
12.6%
9.3%
Carbon
conversion
Tools for diagnostic purposes need to be separated between services, fabric and occupants,
and need to better separate unregulated emissions between the different components
8.6%
IAQ
Integrated tool needed
8.6%
BMS
Inadequate at the medium to small scale
6.6%
Hot box
Greater understanding of the benefits/ test methods/ capability needed
6.6%
Sub metering
Not used properly
6.0%
Airtightness
No detail given
5.3%
Meters
Many meters with financial implications do not currently give adequate confidence to investors
2.0%
Occupancy
Lack of easy measurement of actual occupancy and activity
2.0%
Smart meters
Need to improve the motivation for smart meters in buildings and communities
2.0%
Co-heating
Need cheap and reliable test, every test is different, every house is different, analysis is
different etc. causing incumbent issues.
1.3%
Heat flux
No comments
0.7%
Sensors
Not accurate in practice
0.7%
7
Putting things right
After discussing the tools available and if they are fit for purpose, suggestions were then made for the major
deficiencies as shown below:
Tool/ need
How to deal with gaps/ deficiencies/ what are the drivers ?
Systematic thermal performance
Part L influence
Green Deal
Industry commitment to part L – homes
Calculated U values vs. Hot box (actual measurements)
Heat meters for hot water
Air movement / ventilation
Need “cheap meters that work”
RHI and metering directive 2016
Less disruptive meters
Special commissioning
Soft Landings/ Building Information Modelling – require open source
for public sector contracts
IP addressable systems
Simpler smarter interfaces
Standards and training
Good test for thermal bridges
What is needed?
Building Management Systems (BMS)
Use seismic, RF and ultrasonic sources and transducers for proxy
assessment (imaging) of thermal bridges
Can also use this approach for thermal envelope tests
Who is needed, and how to achieve this?
NDT community eg RCNDE
Oil and gas exploration community
Ground-penetrating radar community (eg Mapping the Underworld
project partners)
Airtightness-type test to evaluate thermal
properties
What is needed?
Inverse tests using temperature sensors and tracer gas
thermal/thermographic imaging
Seismic , microwave, or ultrasonic (imaging) tests
Type-test new builds
Establish protocols for legacy infrastructure
Who is needed, and how to achieve this?
Build on existing work by DCLG or NHBC foundation and protocols
like PSTAR
Academic community e.g. UCL, Coventry
BSI, SEN for standards
Note that an EU protocol is coming
Software- to process the data from sensors and
enable intelligent decisions to be made
What is needed?
Standardise data protocols for sensors
Better and specific training for Building Managers
Highlight incentives for improved energy efficiency and management
Highlight the essential vs. secondary services required from a BEM
system
Who is needed, and how to achieve this?
Improvement of the competence of the user
BEM system suppliers
Energy utilities
Open source application community?
Sensor industry bodies and standards bodies (SEN, ISO, ISA, Linbus)
Building R&D tools should be used by trained research staff
8
Validation and delivery tools should be used by accredited installers
On-going measurement in use to be used by building manager or
experienced service agent
A simple before-and after energy measurement
tool (using all necessary modalities and
technologies)
What is needed?
A pilot study on a large number of buildings, using as large suite of
tools, with suitable data processing and integration, especially the 3D
aspects
Input and output must use standard protocols
Can buildings hold standardised diagnostic information
Who is needed, and how to achieve this?
Industrial and academic players with suitable experience eg F1,
automotive, aerospace
Software (or physical) feedback method to the
user- in terms the user will react to
What is needed?
Find new ways of applying and maintain peer pressure and feedback
Research ways of holding attention to feedback on energy use
Who is needed, and how to achieve this?
The advertising/marketing community
The “Energy in the Community project”
The social networking community (ICT KTN/CDE SIG?)
Product design and user interface specialists
TAS and EPC data never informed by DEC data
What is needed?
Standard protocol for interchange (EPC already standardised, but
DEC are industry-specific)
Physical validation of models and simulations
Who is needed, and how to achieve this?
No good tools for measuring airflow / volume in
spaces (whether with mechanical or natural
ventilation). The challenge is to measure this in
terms of the volume of air in the space. This is a
ventilation not an infiltration problem
Tools are inadequate in terms of the direct
measurement and conversion factors of carbon
and people do not have confidence in them but
are increasingly important in informing decisions
on investment in new build and retrofit
No simple tools for checking performance with
the Building Regulations for (a) energy and (b)
Part F (Building Regulations) and others at each
stage of the process
Existing BPE players
All commercial building (operators?) as they do not have DEC already
Chartered surveyor, and energy assessor communities
CIPSE and DCLG
Current tools only work for R&D, and one off tests, not
continuous
Need to specify what tools are needed for, e.g. (a) to balance
ventilation systems and (b) measure quality
Is there a market need for these measurements? Not yet, but
there will be with near zero carbon buildings
Ideally there would be a smart meter measuring levels of
ventilation at any time
To deliver this smart meter more R&D and demos are needed
From this quantification, how much heat loss due to ventilation
could be calculated
Commercialisation is the main issue with the air quality tools and
particularly the need to combine them into one system (which
also needs R&D)
All tools need more market uptake
Not helped by the conflict between some directives and others
Will be even more important with unregulated emissions
Need is mainly to understand the sensitivity of the measures
DECC figures need to be stable
We need a competition to “Design a simple tool for regulation
outcome compliance”
Tools for acoustic testing are sufficient but overall energy
efficiency is not
Energy use some months in might be ideal but what we need
with current legislative framework is something that works at
handover of the building
A simplified “co-heating” test or equivalent is needed:
1. Report on state of the art of co-heating tests
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2.
Tools for diagnostic purposes need to be
separated between services, fabric and
occupants
R&D paid for by EPSRC, govt, NHBC, LABC, GHA etc.
Can be done with matched behaviour
May need to look at a range – the uncertainty is bound to
be high, but could allow for that
3. Could it become a tool to demonstrate greater value?
Needs to be based on better measurement
Need to separate energy use from services with performance of
fabric
Suggestions and Comments
We would very much welcome your comments, thoughts, ideas on the above notes. If you would
like to get in touch please contact Email: [email protected] Tel: 020 8943 8746 (Measurement
Network).
References
1. Bell, M. et al. (2010) Low Carbon Housing - Lessons from Elm Tree Mews.
http://www.jrf.org.uk/sites/files/jrf/low-carbon-housing-full.pdf
2. The Royal Academy of Engineering. (2012) Engineering a low carbon built environment. The
discipline of Building Engineering Physics.
http://www.raeng.org.uk/education/vps/pdf/Engineering_a_low_carbon_built_environment.pdf
Images courtesy of iStockphoto
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Invited Guests
Company
Name
AECOM
Malcolm Orme
Alex Moody
Alex Moody
Arup
Barry Austin
BLP insurance
Jeff Maxted
BLP insurance
Kim Vernau
BRE
Andy Dengel
BSRIA
Alan Gilbert
CIBSE
Hywel Davies
DCLG
Paul deCort
DECC
Andrej Miller
IET
Bruce McLelland
IET
Cameron Steel
Institute for Sustainability
Lisa Pasquale
LABC
Paul Everall
LABC
Paul Everall
NHBC
Neil Smith
NPL
Ray Williams
NPL
Martin Whickham
NPL
Alistair Forbes
Ofgem
Edmund Ward
TSB BPE programme
Ian Mawditt
TSB BPE programme
Frank Ainscow
TSB BPE programme / BSRIA
Peter Tse
TSB BPE programme / BSRIA
Rod Bunn
TSB BPE programme / Verco
Robert Cohen
TSB BPE programme / BSRIA
Richard John
TSB BPE programme / Cambridge Architectural Research
Jason Palmer
TSB BPE programme / Oxford Brookes
Rajat Gupta
Welsh School of Architecture
Ian Knight
Zero Carbon Hub
Sarah Downes
Zero Carbon Hub
Rob Pannell
MBEKTN
Anne King
Measurement Network
Peter Benson
Measurement Network
Tiju Joseph
TSB
Kerry Mashford
TSB
Mat Colmer
TSB
Ian Meikle
Coventry University
Mark Gatterell
ESKTN
Derek Pedley
ESPKTN
Carlos Huggins
Halcrow
Steve Faulkner
Coventry
Petar Stojic
Coventry
Michael Knight
Coventry
Mark Geterell
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