Table Of ContentBuilding energy metering
CIBSE TM39: 2009
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Engineering a sustainable
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The Chartered Institution of Building Services Engineers
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© November 2009 The Chartered Institution of Building
Services Engineers London
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ISBN 978-1-906846-11-4
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the time of publication. However no responsibility of any
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Typeset by CIBSE Publications
Printed in England by Stephen Austin & Sons Ltd., Hertford,
SG13 7LU
Cover illustration: submeters installed at CIBSE headquarters
as part of the CIBSE Carbon 60 Project; photograph by Paul
Willats Photography (www.paulwillats.co.uk)
Note from the publisher
This publication is primarily intended to provide guidance to those responsible for the
design, installation, commissioning, operation and maintenance of building services. It is
not intended to be exhaustive or definitive and it will be necessary for users of the guidance
given to exercise their own professional judgement when deciding whether to abide by or
depart from it.
Printed on recycled paper
Foreword
This publication was first issued in 2006, based on the Energy Efficiency Best Practice
Programme’s General Information Leaflet GIL065, to provide guidance for designers of
new non-domestic buildings on meeting the metering requirements of Part L of the
Building Regulations. This revision provides good-practice guidance covering the general
application of building energy metering, in addition to the metering requirements of the
Building Regulations for England and Wales and for Northern Ireland, and the Scottish
Building Standards.
As well as the metering requirements in Building Regulations and standards, the Energy
Performance of Buildings Regulations 2007 introduces further energy metering require -
ments. Additional imminent challenges include the proposed revisions to Part L of the
Building Regulations and the introduction of the detailed requirements for the Carbon
Reduction Commitment (CRC). This will apply to all organisations that use more than
6000MW·h per year. There may also be additional metering requirements arising from the
recasting of the Energy Performance of Buildings Directive.
Previous versions of TM39 have also included energy estimation techniques. Although
these are not ‘metering’ in the strictest sense, they provide valuable energy management
data. However, this edition of TM39 focuses on the actual metering requirements, and so
the energy estimation techniques previously included in TM39 will in future be included
in CIBSE TM22: Energy assessment and reporting method. A revised version of TM22
incorporating these changes is anticipated in mid-2010.
Additionally, the British Property Federation has developed an energy management tool
called LES-TER, which stands for Landlord’s Energy Statement, Tenant’s Energy Review.
This is a voluntary scheme to support energy management in multi-tenanted office
buildings, which has raised awareness of the difficulty of quantifying the division between
the energy used by the landlord and the tenant(s), particularly in existing buildings that do
not lend themselves easily to retrofitting direct metering for this purpose. In this situation,
it tends to be as, if not more, important to know what is happening in each tenancy rather
than what is happening at a whole-building level, with a breakdown by end-use.
GIL065 and the 2006 edition of TM39 suggested strategies for addressing individual
tenancies within a building. This new edition of TM39 provides a more general, less
prescriptive approach to energy metering for both new and existing buildings, allowing
designers and facilities managers to develop a metering strategy which is tailored to meet
the particular requirements of a specific project.
The aims of TM39 are as follows:
— For new buildings and existing buildings being altered or extended: to show ways
of demonstrating compliance with relevant building regulations.
— For new and existing buildings: to show ways of meeting the statutory requirements
for DECs as well as any future legislation, such as the Carbon Reduction
Commitment and changes to the Energy Performance of Buildings Directive and
its implementing regulations.
— For all buildings: to indicate good practice metering strategies and implemen -
tations to underpin proactive building energy management.
It is worth noting that, although water usage in buildings is of growing importance, due to
both increased costs and increased environmental factors, this update of TM39 relates to the
metering of energy and does not include water.
Ellen Salazar
Principal author
Author
Ellen Salazar (ES Research and Consultancy)
Contents
1 Introduction 1
2 Costs and benefits of submetering 1
3 Overview of TM39 metering methodology 3
4 Methodology 3
4.1 Step a: Select the TM39 boundary 3
4.2 Step 2: List all energy imported and exported across boundary 4
4.3 Step 3: List all energy-using items within boundary 4
4.4 Step 4: Decide which items should be metered 4
4.5 Step 5: Select appropriate meter for each item 6
4.6 Step 6: Decide location(s) of meter(s) 8
4.7 Step 7: Decide how the meters are to be read 9
4.8 Step 8: Review the metering strategy 10
4.9 Step 9: Specify, implement and commission the metering 11
4.10 Step 10: Documenting the strategy 11
4.11 Case study: Manchester Science Park: Kilburn House 11
4.12 Example from the CIBSE Carbon 60 Project 13
5 Analysis of meter readings 15
5.1 Display Energy Certificates 15
5.2 Landlord Energy Statement and Tenant Energy Review 15
(LES-TER)
5.3 Energy benchmarks 16
5.4 Energy assessment and reporting method 16
5.5 Demand profiling using half-hourly electricity data 17
References 17
Appendix A1: Case studies 18
Appendix A2: Alignment and synchronicity requirements for DECs 27
1
Building energy metering
1 Introduction — motivating operational improvements by owners,
occupiers, users, management and outsourced
contractors.
This document promotes best practice in the design of
energy metering and submetering in non-domestic
buildings. It will also help facilities managers to introduce The objectives of the TM39 metering and submetering
metering and submetering in their existing buildings. To methodology are to enable the design of metering
this end, it has been written for designers, owner- strategies and systems to meet the purposes described
occupiers, landlords and the letting agents who act on above, in that they:
their behalf, managing agents, tenants, office managers,
(1) gather accurate and useful energy consump tion
facilities managers, and anyone else who can benefit from
data (kW·h) about actual energy use
the energy data that meters and submeters can provide.
(2) determine where the energy is used (site, building,
This edition of TM39 offers a cost-effective and practical tenancy, activity area, etc.)
approach to procuring energy metering systems. It should
(3) provide this information, in a user-friendly format,
be used to optimise the metering strategy against cost,
to whoever needs it, in order to:
practicality, the value of the information gained and future
energy savings. A step-by-step method is provided to
— manage buildings and improve operational
assist in the selection of appropriate ways of metering
efficiency
energy use and the provision of information, including
provision of a logbook, for building owners and occupiers. — isolate ‘separables’ and other items not
typically included in energy benchmarks
Owners and operators of existing buildings will benefit
— take account of renewable energy systems
from implementing a comprehensive metering strategy to
by measuring their performance
help manage the energy consumption* in their buildings
more effectively. Submetering in itself does not save
(4) document the metering strategy in the building
energy; it provides information about how much energy is
logbook (see CIBSE TM31: Building log book
being used, and where it is being used. It is action taken as toolkit(1)).
a result of installing meters and using the information the
meters provide that can achieve quantifiable energy
Figure 1 provides a summary of the TM39 methodology.
savings. Meters that are selected, installed and commis -
sioned correctly will provide the information needed for
the effective monitoring and targeting process that is an
essential part of good energy management practice. 2 Costs and benefits of
Installing a meter will not save energy on its own. There submetering
must also be a system in place to ensure periodic reading
of the meter. Energy-saving action must be carried out as a The financial value of metering is dependent on the
result of the information provided by the meter. For reduction in the energy costs due to having and using
example, a meter that identifies pumps that do not need to additional data about energy use.
be running continuously may save 60% of the energy
consumed by them, whereas a meter measuring well-
For example, in an office having a floor area of 500m2,
controlled services will save little. A meter that is not read,
with a lighting load of 12W/m2, intended to be operating
or the readings not acted upon, will save nothing.
for 10 hours per day on weekdays only, the running cost of
the lighting, at 10p/kW·h, is of the order of £1500 per
Before deciding on a metering strategy, it is essential to
year.
identify the purposes for which metering and monitoring
are being considered, including:
To evaluate whether it is cost-effective to install a lighting
— billing and recharging submeter, the cost of the meter should be compared with
the cost of the additional energy that would be used if the
— performance tracking, reporting and bench -
lighting were left on longer than intended as, without the
marking
meter, the building operator would probably not be aware
— facilities, energy and carbon management of this wastage. If the lights were needlessly left on for an
additional 2 hours per day, this would equate to an extra
— fault detection, and enabling technical insights
£300 per year spent on electricity. If having the submeter
* For the purposes of this document, metered energy is expressed as helped to ensure that the lights were switched off when
energy consumption. not required, then the simple payback period for the
1
Building energy metering
1 Introduction — motivating operational improvements by owners,
occupiers, users, management and outsourced
contractors.
This document promotes best practice in the design of
energy metering and submetering in non-domestic
buildings. It will also help facilities managers to introduce The objectives of the TM39 metering and submetering
metering and submetering in their existing buildings. To methodology are to enable the design of metering
this end, it has been written for designers, owner- strategies and systems to meet the purposes described
occupiers, landlords and the letting agents who act on above, in that they:
their behalf, managing agents, tenants, office managers,
(1) gather accurate and useful energy consump tion
facilities managers, and anyone else who can benefit from
data (kW·h) about actual energy use
the energy data that meters and submeters can provide.
(2) determine where the energy is used (site, building,
This edition of TM39 offers a cost-effective and practical tenancy, activity area, etc.)
approach to procuring energy metering systems. It should
(3) provide this information, in a user-friendly format,
be used to optimise the metering strategy against cost,
to whoever needs it, in order to:
practicality, the value of the information gained and future
energy savings. A step-by-step method is provided to
— manage buildings and improve operational
assist in the selection of appropriate ways of metering
efficiency
energy use and the provision of information, including
provision of a logbook, for building owners and occupiers. — isolate ‘separables’ and other items not
typically included in energy benchmarks
Owners and operators of existing buildings will benefit
— take account of renewable energy systems
from implementing a comprehensive metering strategy to
by measuring their performance
help manage the energy consumption* in their buildings
more effectively. Submetering in itself does not save
(4) document the metering strategy in the building
energy; it provides information about how much energy is
logbook (see CIBSE TM31: Building log book
being used, and where it is being used. It is action taken as toolkit(1)).
a result of installing meters and using the information the
meters provide that can achieve quantifiable energy
Figure 1 provides a summary of the TM39 methodology.
savings. Meters that are selected, installed and commis -
sioned correctly will provide the information needed for
the effective monitoring and targeting process that is an
essential part of good energy management practice. 2 Costs and benefits of
Installing a meter will not save energy on its own. There submetering
must also be a system in place to ensure periodic reading
of the meter. Energy-saving action must be carried out as a The financial value of metering is dependent on the
result of the information provided by the meter. For reduction in the energy costs due to having and using
example, a meter that identifies pumps that do not need to additional data about energy use.
be running continuously may save 60% of the energy
consumed by them, whereas a meter measuring well-
For example, in an office having a floor area of 500m2,
controlled services will save little. A meter that is not read,
with a lighting load of 12W/m2, intended to be operating
or the readings not acted upon, will save nothing.
for 10 hours per day on weekdays only, the running cost of
the lighting, at 10p/kW·h, is of the order of £1500 per
Before deciding on a metering strategy, it is essential to
year.
identify the purposes for which metering and monitoring
are being considered, including:
To evaluate whether it is cost-effective to install a lighting
— billing and recharging submeter, the cost of the meter should be compared with
the cost of the additional energy that would be used if the
— performance tracking, reporting and bench -
lighting were left on longer than intended as, without the
marking
meter, the building operator would probably not be aware
— facilities, energy and carbon management of this wastage. If the lights were needlessly left on for an
additional 2 hours per day, this would equate to an extra
— fault detection, and enabling technical insights
£300 per year spent on electricity. If having the submeter
* For the purposes of this document, metered energy is expressed as helped to ensure that the lights were switched off when
energy consumption. not required, then the simple payback period for the
2 Building energy metering
START FINISH
Step 1
Step 10
Select the boundary within which TM39 will be applied.
Draw this onto a plan drawing of the floor, the building, Ensure a copy of the metering strategy is included in the
or the site, as appropriate. building log book. This should include the plan drawing(s)
showing the TM39 boundary, the meter locations, etc.
It should also contain any key decisions made about data
collection and management, including a description of
how meter readings will be processed and the required
Step 2 reporting formats and frequencies for different audiences,
e.g. half-hourly, daily, weekly, monthly, quarterly, annual.
List all energy that is imported (and exported,
if applicable) across this boundary. This includes all
mains supplies plus renewable energy, low and zero
carbon systems (LZCs) and district heating/cooling.
These should generally all be separately metered.
Step 9
Specify, implement and commission the metering and
submetering decided in step 8.
Step 3
List all items within the boundary that will be supplied.
These could be end-uses, technologies, tenancies or
other activity areas. Step 8
Review metering strategy for appropriateness,
complexity and cost-effectiveness. Go back to step 4
if revisions are required.
Step 4
Decide which of these items should be metered or
submetered. CIBSE TM22 can help focus on the main
items using energy within the boundary. Where Building
Step 7
Regulations apply, systems should be provided to
enable 90% of the estimated energy consumption Decide how the meters are to be read. For automatically
of each fuel to be metered. Consider how the energy read meters, ensure that readings can be gathered for
data collected within the boundary might need to be analysis, particularly if there is an existing aM&T system.
or could best be used, e.g. by a client with several Integration packages may be required.
buildings, or by a local authority with many schools
reporting under the CRC provisions.
Step 6
Step 5 Determine where to locate the meters. Mark the
plan to show, within the boundary, which
Select the appropriate meters or method for each item meter is located where. Remember to consider
to be metered or submetered. access to the meters so they may be easily read.
Figure 1 Summary of TM39 methodology
submeter would probably be very short, and installation of
the meter would be considered cost-effective.
Portable meters
However, the ease with which data from the submeter can
be used by the building operator should also be Portable meters with a data logging capability can
considered, as well as the building operator’s willingness be a cost-effective alternative to diagnose problems
to act on this information to keep the lights switched off in areas where fixed, permanent metering would
when they are not required. If this lighting submeter is to not be justifiable financially. Once a problem is
deliver any benefit, then the information it provides must lead to corrected, the data logging meters can be easily
the switching-off of unneeded lights. removed and redeployed elsewhere.
Metering hardware has become relatively inexpensive in In addition to recording energy use, measuring
recent years, and this can give rise to a temptation to other indoor environmental quality (IEQ) parameters,
meter almost every end-use consumer. However, unless such as temperature and relative humidity (RH), can
the meter is going to be regularly read, the data analysed, provide valuable data for improving internal
decisions made and action taken, there is little benefit in conditions whilst minimising energy use.
fitting additional metering.
Methodology 3
3 Overview of TM39 4.1 Step 1: Select the TM39
metering methodology boundary
On a plan drawing, a line should be drawn around the area
There are many reasons for metering; identifying the
to which TM39 is being applied. This line is called the
overarching purpose for metering on a particular project
boundary line, and the TM39 methodology should be
can help guide the project team toward the best overall
applied to everything within this boundary.
approach to metering and submetering. Consideration
should be given to the following:
On a site with a single building, this will typically be a
(a) Whole building benchmarking: this could be for line around the building that includes all areas associated
Display Energy Certificates (DECs), to comply with the building, both inside and outside (e.g. the
with Building Regulations(2), or to meet local building’s external lighting), where energy is consumed or
authority requirements. Consider main supplies, produced.
on-site renewable energy, low and zero carbon
(LZC) fuels and technologies, and separables.
New buildings: Part L compliance
(b) Billing or management of parts within a whole: this
could apply to tenancies or departments within a Where TM39 is being applied to demonstrate
building, buildings on a campus, etc. Meter or compliance with Part L for a new building, the
submeter all sensible parts (e.g. all electricity ‘single building’ approach is often appropriate.
within a part). Heating, cooling and ventilation
from a whole-building system are not generally
When several buildings, either new or existing, are located
submetered for parts within a building. This may
on a site with other existing buildings, the line is drawn
be appropriate for a building with multiple
around the buildings being considered, and this becomes
occupants that is within the scope of the Carbon
the boundary for the purposes of applying TM39.
Reduction Commitment(3)(CRC) arrangements
(c) Technical energy analysis by end-use: meter at least In buildings with a sole occupier, measuring energy
90% of each supply by end-use, or provide a consumption in order to enable building users to manage
reasonable methodology for estimation if not their use of energy better is straightforward. In buildings
directly metered. CIBSE TM22: Energy assessment with multiple tenants the practical details are more
and reporting method(4) can help in estimating end- complex but such information is increasingly required to
uses that are not directly metered. enable public authority tenants to comply with the Energy
Performance of Buildings Regulations 2007(5) and, from
(d) Building profile demand management: half-hourly 2010, to meet the requirements proposed under the
consumption data for whole building electricity Carbon Reduction Commitment(3).
use (often available, particularly for electricity
meters >100kW, and natural gas, if appropriate). To address this growing need for information about energy
use in multi-tenanted buildings, the British Property
(e) Profile management of parts: as (b) above, but half-
Federation, the Usable Buildings Trust, CIBSE and the
hourly, or plant items/end-uses as (c) above, but
British Council for Offices, with support from the Carbon
half-hourly.
Trust, have developed the Landlord’s Energy Statement
(LES), and the Tenant’s Energy Review (TER), together
known as LES-TER. These tools enable landlords and
Subdivided properties
tenants to identify the energy being used in the building,
and who is using it. Consider the LES-TER diagram of a
Where properties have been subdivided, existing
multi-tenanted office block shown in Figure 2.
meters may not be monitoring all loads; or worse,
they may be monitoring loads from adjacent units.
There are many boundaries that could be drawn,
This is most common where buildings have been
depending on who the stakeholders are and what is being
subdivided/sub-let over time.
considered for the purposes of TM39. If the managing
agent used TM39 to improve data management in this
building to better inform the energy management
It is also worth considering who will use this information,
initiatives implemented on behalf of the landlord, the
and in what format it should be presented for best effect.
boundary would be drawn as shown in Figure 3.
Once the overall goals have been agreed, the flowchart
(Figure 1) and subsequent text illustrate the TM39
methodology for developing a metering and submetering Office tenant 1
s
strategy that will allow energy use to be monitored in a art Office tenant 2 Direct energy
practical, informative and cost-effective way. n p Office tenant 3 supplies to
o each office
m Office tenant 4 tenant
m
o Office tenant 5
C
4 Methodology Independent shop unit
(outside office boundary)
This section gives more detailed guidance for each of the
ten steps in the metering methodology. Section 4.11 is a Energy supplied in Independent energy
landlord’s services supplies to shop unit
case study for a building at Manchester Science Park that
illustrates the process of preparing a metering strategy. Figure 2 LES-TER diagram for a multi-tenanted office
Methodology 3
3 Overview of TM39 4.1 Step 1: Select the TM39
metering methodology boundary
On a plan drawing, a line should be drawn around the area
There are many reasons for metering; identifying the
to which TM39 is being applied. This line is called the
overarching purpose for metering on a particular project
boundary line, and the TM39 methodology should be
can help guide the project team toward the best overall
applied to everything within this boundary.
approach to metering and submetering. Consideration
should be given to the following:
On a site with a single building, this will typically be a
(a) Whole building benchmarking: this could be for line around the building that includes all areas associated
Display Energy Certificates (DECs), to comply with the building, both inside and outside (e.g. the
with Building Regulations(2), or to meet local building’s external lighting), where energy is consumed or
authority requirements. Consider main supplies, produced.
on-site renewable energy, low and zero carbon
(LZC) fuels and technologies, and separables.
New buildings: Part L compliance
(b) Billing or management of parts within a whole: this
could apply to tenancies or departments within a Where TM39 is being applied to demonstrate
building, buildings on a campus, etc. Meter or compliance with Part L for a new building, the
submeter all sensible parts (e.g. all electricity ‘single building’ approach is often appropriate.
within a part). Heating, cooling and ventilation
from a whole-building system are not generally
When several buildings, either new or existing, are located
submetered for parts within a building. This may
on a site with other existing buildings, the line is drawn
be appropriate for a building with multiple
around the buildings being considered, and this becomes
occupants that is within the scope of the Carbon
the boundary for the purposes of applying TM39.
Reduction Commitment(3)(CRC) arrangements
(c) Technical energy analysis by end-use: meter at least In buildings with a sole occupier, measuring energy
90% of each supply by end-use, or provide a consumption in order to enable building users to manage
reasonable methodology for estimation if not their use of energy better is straightforward. In buildings
directly metered. CIBSE TM22: Energy assessment with multiple tenants the practical details are more
and reporting method(4) can help in estimating end- complex but such information is increasingly required to
uses that are not directly metered. enable public authority tenants to comply with the Energy
Performance of Buildings Regulations 2007(5) and, from
(d) Building profile demand management: half-hourly 2010, to meet the requirements proposed under the
consumption data for whole building electricity Carbon Reduction Commitment(3).
use (often available, particularly for electricity
meters >100kW, and natural gas, if appropriate). To address this growing need for information about energy
use in multi-tenanted buildings, the British Property
(e) Profile management of parts: as (b) above, but half-
Federation, the Usable Buildings Trust, CIBSE and the
hourly, or plant items/end-uses as (c) above, but
British Council for Offices, with support from the Carbon
half-hourly.
Trust, have developed the Landlord’s Energy Statement
(LES), and the Tenant’s Energy Review (TER), together
known as LES-TER. These tools enable landlords and
Subdivided properties
tenants to identify the energy being used in the building,
and who is using it. Consider the LES-TER diagram of a
Where properties have been subdivided, existing
multi-tenanted office block shown in Figure 2.
meters may not be monitoring all loads; or worse,
they may be monitoring loads from adjacent units.
There are many boundaries that could be drawn,
This is most common where buildings have been
depending on who the stakeholders are and what is being
subdivided/sub-let over time.
considered for the purposes of TM39. If the managing
agent used TM39 to improve data management in this
building to better inform the energy management
It is also worth considering who will use this information,
initiatives implemented on behalf of the landlord, the
and in what format it should be presented for best effect.
boundary would be drawn as shown in Figure 3.
Once the overall goals have been agreed, the flowchart
(Figure 1) and subsequent text illustrate the TM39
methodology for developing a metering and submetering Office tenant 1
s
strategy that will allow energy use to be monitored in a art Office tenant 2 Direct energy
practical, informative and cost-effective way. n p Office tenant 3 supplies to
o each office
m Office tenant 4 tenant
m
o Office tenant 5
C
4 Methodology Independent shop unit
(outside office boundary)
This section gives more detailed guidance for each of the
ten steps in the metering methodology. Section 4.11 is a Energy supplied in Independent energy
landlord’s services supplies to shop unit
case study for a building at Manchester Science Park that
illustrates the process of preparing a metering strategy. Figure 2 LES-TER diagram for a multi-tenanted office
4 Building energy metering
case, for a single building with a direct gas and electricity
Managing agent’s
supply, this would show the gas meter and the electricity
boundary
meter measuring all energy entering the boundary, with
Office tenant 1
no energy exported across the boundary.
s
art Office tenant 2 Direct energy
p supplies to
n Office tenant 3
o each office
m Office tenant 4 tenant Existing buildings
m
o Office tenant 5
C
In existing buildings, to ensure that all energy-using
Independent shop unit
equipment is identified, switch off all known
(outside office boundary)
devices, and then check the meter. This should be
repeated until the meter shows zero consumption.
Energy supplied in Independent energy
Be prepared to take time over this step; it is not
landlord’s services supplies to shop unit
unusual for loads to be forgotten.
Figure 3 LES-TER diagram for a multi-tenanted office to inform energy
management initiatives implemented on behalf of the landlord
4.3 Step 3: List all energy-using
items within boundary
Tenant 1 fit-out
team’s boundary
Once the energy flowing across the boundary has been
Office tenant 1
accounted for, list all major items within the boundary
s
art Office tenant 2 Direct energy that will be supplied.
p supplies to
n Office tenant 3
o each office
m Office tenant 4 tenant These could be end-use technologies, tenancies or other
m activity areas, for example;
o Office tenant 5
C
— heating, lighting, computer servers, catering (e.g.
Independent shop unit
staff restaurant in an office building)
(outside office boundary)
— fixed building services in a multi-tenanted office,
Energy supplied in Independent energy measuring the split between landlord energy in
landlord’s services supplies to shop unit common areas and energy in each tenancy
Figure 4 LES-TER diagram for a multi-tenanted office showing office — retail space(s) on the ground floor of an office
tenant1’s TM39 boundary block
— coffee bar franchise in the waiting area of a
hospital or rail station.
Equally, if tenant 1’s fit-out team used TM39 to create a
metering strategy for use within this tenancy, then the
Refer to Table 1(4) to ensure that the main energy-using
boundary would be drawn as shown in Figure 4.
items are metered.
Portfolio management
Listing energy-using items
If the area within the boundary is part of a larger
site or portfolio, consider how the data collected
For simple situations, this can be done on the same
within the boundary will relate to the portfolio level
plan drawing but for more complicated scenarios, it
analysis. For example:
might be necessary to use a separate drawing or
— Are meters synchronised to take readings at some other means of communicating this infor -
the same interval so that data can be mation graphically.
compared?
Remember that copies of these drawings will be
— Do the items measured at boundary level fit
included in the building logbook, particularly if
with the items examined at portfolio level,
TM39 is being used to demonstrate compliance
without gaps or overlaps?
with Building Regulations Part L. So whatever
graphical method is used, it should be clear and
easily understood by a non-technical reader.
4.2 Step 2: List all energy imported
4.4 Step 4: Decide which items
and exported across boundary
should be metered
On the same plan drawing, show all of the incoming and
outgoing energy used/produced within the boundary. This Once the items within the boundary have been listed,
should include both the import and export of energy decide which of them needs to be metered to achieve the
across the boundary by energy producers and consumers objectives stated in the metering strategy. Consider how
such as district heating/cooling, renewable energy supplies the energy data collected within the boundary will be used
and low and zero carbon systems (LZC). In the simplest (e.g. by an owner-occupier, or a client with several
