Table Of ContentRefurbishment for
improved energy
efficiency: an overview
CIBSE Knowledge Series: KS12
Principal author
Kevin Pennycook, BSRIA
Knowledge Series editor
Helen Carwardine
Editors
Helen Carwardine
Ken Butcher
Publishing Manager
Jacqueline Balian
CIBSEKnowledge Series — Refurbishment
cover mock-up 1 22/10/07 11:18 Page 3
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in any form or by any means without the prior permission of the Institution.
© October 2007 The Chartered Institution of Building Services Engineers London
Registered charity number 278104
ISBN: 978-1-903287-88-0
This document is based on the best knowledge available at the time of publication.
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Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
2 Why refurbish? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
3 Refurbishment challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
4 Refurbishment assessment procedure . . . . . . . . . . . . . . . . . . . . . .8
5 Pre-refurbishment energy checks . . . . . . . . . . . . . . . . . . . . . . . . .13
6 Lower cost refurbishment options . . . . . . . . . . . . . . . . . . . . . . . .14
7 Higher cost refurbishment options . . . . . . . . . . . . . . . . . . . . . . . .22
8 Low or zero carbon technologies . . . . . . . . . . . . . . . . . . . . . . . . .33
9 Commissioning/recommissioning . . . . . . . . . . . . . . . . . . . . . . . . . .37
10 Handover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Appendix A: Refurbishment procedures and options flow chart . . .41
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
CIBSEKnowledge Series — Refurbishment
1 Introduction
With increased awareness of the importance of energy efficiency in buildings,
not only to reduce carbon emissions but also to meet regulatory and planning
requirements, refurbishment of building services is currently an important
subject.
Whilst we build 1% of the stock new each year, 99% of the stock is already
with us – whenever a building is refurbished it is an opportunity for building
services engineers to add value and reduce energy costs and carbon
emissions through energy efficient measures. The introduction of energy
performance certificates (EPCs) may result in tenants demanding better
energy performance from their buildings and this publication will show ways
of achieving this.
This is a joint CIBSE and BSRIA publication that will provide guidance to
building services engineers who are tasked with upgrading existing services. It
will help building occupiers and managers to understand the minor
refurbishment steps that can be taken to improve the energy efficiency of
their building services. Members from both organisations are involved in
operating buildings and refurbishment presents them with a large challenge,
as well as a significant opportunity. This publication brings together the wide
range of sources of information available from both CIBSEand BSRIAto
demonstrate to building services engineers the refurbishment options that are
available to them.
Retrofit for energy efficiency should not be undertaken in isolation from the
other drivers and considerations relating to building refurbishment. Examples
include occupancy comfort, health and productivity, future flexibility and
adaptability of services and maintenance and upkeep issues.
This Knowledge Series publication is intended to provide a concise overview
of building services refurbishment with a focus on improving energy
efficiency. It is not intended to give an in-depth review of the various
refurbishment issues and options, rather it is an introduction to the various
topics along with sources of in-depth guidance.
Note that refurbishment options outlined in this publication include ‘lower
cost’ and ‘higher cost’ options. In practice, what constitutes lower and higher
cost will be highly dependant on the specific building, its existing building
services and desired levels of improvement.
Further information on all of the aspects covered in this publication can be
found in other existing CIBSE and BSRIA publications, and these are indicated
throughout.
CIBSEKnowledge Series — Refurbishment 1
2 Why refurbish?
Building services systems are refurbished for a variety of reasons. For
example, the replacement of old and inefficient plant, changes in use or the
extension of buildings. The principal aim when refurbishing building services
systems is to provide optimum system performance for minimum capital
outlay, ensuring appropriate comfort conditions are maintained at the least
possible rate of energy expenditure and consequent CO2emissions. In reality
these aims are not always fully realised.
The benefits of refurbishment are wide and can include the following:
— provide for a change in use of the building
— attract higher rents
— produce a higher return on capital
— help sell or rent a building
— retain existing tenants
— create more lettable floor space
— compete with other new/refurbished properties in the same market
place
— provide improved environmental comfort conditions
— provide a lower-cost option than moving to a new building
— provide better operating characteristics.
The following factors influence the requirement for building services
refurbishment.
2.1 Reduced energy consumption/CO2 emissions
During previous decades energy has been relatively cheap and this has
hindered the adoption of energy-saving building services solutions. Recent
years have seen a steep rise in energy prices and it is highly likely that these
prices will further increase in real terms, due to increasing world demand for
energy along with strategic considerations. There is now widespread
awareness of climate change and the influence of manmade CO2emissions
along with the significant contribution that the buildings sector makes to CO2
emissions. These factors have raised the profile of building-related energy
consumption and consequently raised the profile of building services
refurbishment.
2.2 Building Regulations
Approved Document L2B: Conservation of fuel and power in existing buildings
other than dwellings(1)imposes a range of energy related requirements on the
design of retrofitted and extended existing buildings. L2B applies to:
2 CIBSEKnowledge Series — Refurbishment
— consequential improvements
— extensions
— buildings subject to a material change of use
— material alterations
— provision of a controlled fitting
— provision or extension of a controlled service
— provision or renovation of a thermal element.
Consequential improvements, required when an extension is built or where
the installed capacity per unit area of heating and cooling systems is
increased, can result in a requirement to:
— upgrade heating, cooling and air-handling systems more than 15 years
old by the provision of new plant or improved controls
— upgrade general lighting systems
— install energy metering
— upgrade thermal elements (walls, roofs etc), and windows and doors
— increase the on-site low and zero carbon energy-generating systems.
Where a building refurbishment requires the installation, extension or
replacement of a controlled service, the work has to meet minimum
standards of energy efficiency. These standards are provided in the Non-
domestic heating, cooling and ventilation compliance guide(2).
Refurbishment projects that are covered by the Building Regulations will
require notification to the local authority building control or an approved
inspector. Certain aspects of refurbishment may be covered by self-
certification schemes.
2.3 The EU Directive on Energy Performance of Buildings
This requires a range of building energy labelling measures to be
implemented in the UK. This implementation is made via Statutory
Instrument 2007/991 and contains requirements for energy performance
certificates to be compiled for all buildings at the time of construction, sale or
rent, and in some cases for certificates to be displayed. The requirements for
certification, and other issues relating to the Directive such as in the
inspection of air conditioning systems, are subject to a rolling timetable.
A method for assessing the energy performance of an occupied building
based on metered energy use that will meet the requirements of the
Directive is provided in CIBSE TM22: Energy assessment and reporting
method(3).
CIBSEKnowledge Series — Refurbishment 3
2.4 Condition of building services
Refurbishment of building services systems can be driven by the age and
condition of the building services equipment. Old, outdated and inefficient
plant will compromise the efficient operation of a building. Retrofitting some,
or all, of the building services systems can provide the following benefits:
— reduced energy consumption and CO2emissions
— reducing heat output from equipment can correspondingly reduce the
demand for cooling
— reduced maintenance requirement
— increased maintenance intervals (therefore reduced maintenance
costs)
— greater reliability
— easier access for inspection and maintenance
— improved supply of spare parts
— easier to obtain suitably trained maintenance staff
— ability to reduce health and safety risks.
2.5 Improved occupant comfort and productivity
The primary aim of building services is to create and maintain a comfortable
environment, however, many existing buildings provide a poor working
environment in terms of occupant comfort. This can have implications for
staff satisfaction with their working conditions, morale, absenteeism, health
and safety, and staff retention. Internal environmental factors that influence
occupant comfort are:
— thermal comfort influenced by air temperature, relative humidity,
mean radiant temperature, and air velocity
— internal air quality influenced by ventilation rates, quality of the
exterior air, building occupants and other sources of internal air
pollution
— visual comfort influenced by illuminance levels, glare, contrast and
colour rendition
— acoustic comfort influenced, in part, by noise from building services
equipment, noise from the exterior, and noise passing from one office
area to another, eg through walls or via ceiling voids.
Successful retrofit actions can address the above issues. Details concerning
occupant comfort are provided in CIBSE KS06: Comfort(4).
4 CIBSEKnowledge Series — Refurbishment
3 Refurbishment challenges
3.1 General
Guidance
Due to the nature of construction sites, health and safety issues present a
challenge to designers and project managers. The most frequent causes of
Guidance concerning the essential tasks
accidental death and injury are: for achieving health and safety objectives
on construction sites is given in the HSE
publication – Managing health and safety
— falls in construction(36).
— mobile plant
— falling material and collapse
— electrical accidents
— trips.
In addition, ill health can result from:
— exposure to asbestos
— injuries resulting from manual handling of heavy and awkward loads
— noise and vibration from tools
— chemical exposure from materials.
As part of many refurbishment projects it is likely that hazardous waste
(referred to as special waste in Scotland) will be encountered. Examples of
hazardous waste include:
— asbestos
— lead-acid batteries (eg used in UPS systems)
— electrical equipment containing hazardous components
— fluorescent light tubes
— chemical wastes.
Organisations that dispose of waste (including the original ‘owners’ of the
waste) have a duty of care to ensure that any waste product is handled safely
and within the law. In England and Wales, sites disposing of hazardous waste
will need to register as producers with the Environment Agency. Guidance
concerning the disposal of waste from refurbished buildings is given at the
following website: www.netregs.gov.uk.
Depending on the nature of the refurbishment project, disruption to the
building occupants may occur. Disruption can be reduced by performing
refurbishment on a floor-by-floor basis and replacing building services
plant/systems out of season, eg replacing a heating system during the summer.
Disruption to the occupants and residents of adjoining properties can be
minimised by following the guidance produced by the Considerate
Constructors Scheme (www.considerateconstructorsscheme.org.uk).
CIBSEKnowledge Series — Refurbishment 5
3.2 Building services specific
The building imposes practical constraints on the refurbishment project, not
just the design but the removal and installation of plant. The following should
be taken into account during the design stage of any retrofit project.
Table 1:
General Presence of asbestos (removal/encapsulation)
Design considerations for
Location of existing services
refurbishment
Isolation of existing services
Safe removal of redundant equipment.
Space and Items of plant
access
Routing of flues, pipes, ducts etc
Equipment installation access
Maintenance access
Repair access
Replacement access.
Space for plant Plant rooms
Riser shafts
Floor voids
Ceiling voids
Conditioned areas.
Weight Plant rooms
constraints
Riser shafts
Ceiling voids
Conditioned areas.
Weight loading Floors
constraints
Ceilings
Roofs
Walls.
The refurbishment assessment and subsequent design stage may be hindered
by a lack of documentation concerning the existing building and its building
services plant. Examples include details of the building fabric thermal
properties and operational capacity of plant. Much of this information can be
gathered during the carrying out of condition surveys.
It is likely that much refurbishment work will be influenced by the
requirements of the Building Regulations (Approved Document L2B and its
associated second tier guidance documents). Examples of how Approved
Document L2B can influence refurbishment are given in section 2.2.
6 CIBSEKnowledge Series — Refurbishment
3.3 Refurbishment specific
Due to the nature of carrying out refurbishment work, especially where part
of the building may remain occupied during the work, there are a number of
additional considerations that need to be taken into account, such as:
— how to identify and isolate the refurbishment work from live services
that need to be protected and remain operational for the building
occupants, eg gas, electricity, broadband
— issues relating to the possible interfacing of existing and new building
services, for example, ensuring that existing hydronic systems are clean
before connection to new systems
— how to reduce the impact of noise and dust on occupants
— the complicated logistics of working around occupants
— the continued operation of life saftey systems where appropriate, such
as fire detection and security detection systems, along with the
maintenance of evacuation routes
— the importance of reducing inconvenience to any neighbours.
Most of these issues will need to be considered and addressed during site
surveys before work begins.
As with any project, whether new build or refurbishment, co-ordination
between those involved in the design and subsequent construction stages is
crucial for success.
CIBSEKnowledge Series — Refurbishment 7
