Sustainable Refurbishment: a Toolkit for Going Green
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Sustainable Refurbishment: a Toolkit for Going Green
Sustainable Refurbishment: a Toolkit for Going Green Contents
Foreword Contents
The beauty, quality and rich heritage of the buildings of Mayfair and Belgravia are cause 1.0 Executive Summary 7
for admiration and delight. The Estate was carefully planned to create the finest locations
in London and it has evolved in response to the particular demands and aspirations of its 2.0 Aspects of Refurbishment 8
original and current, past and present occupiers.
Now we share a similar responsibility to respond to the needs and concerns of today’s and Initial Steps
tomorrow’s occupiers. We need to take account of world-wide concerns about a planet in a 2.1 Upgrading the Lighting and Electrical Systems 10
dramatic state of flux which places demands on us all to address substantial environmental
2.2 Redecorating and Choosing Materials 12
and social issues.
2.3 Case Study: 15 Passmore Street 14
While significant progress has been made in improving the sustainability of new buildings, 2.4 Upgrading the Heating and Plumbing Systems 16
improving the environmental performance of existing buildings, and particularly historic 2.5 Upgrading Water Fittings 18
buildings, has proved to be much more challenging. It is for this reason that we decided 2.6 Choosing a Contractor 20
to produce this simple guide designed for building owners who may be contemplating
renovating their property, either in part or in whole, who want to be able to improve the
Windows in Traditional Buildings
environmental performance of their building but are not quite sure where to start or what to
prioritise first. 2.9 Upgrading Windows in a Conservation Area 24
2.10 Upgrading Windows of a Listed Property 26
While this toolkit is not intended to be a comprehensive guide to retrofitting your property,
we hope that both you and your appointed consultants will find it helpful in assessing your
options and opportunities. Many of the techniques, products and approaches illustrated in Advanced Measures
the guide have been used by Grosvenor on its own development projects and refurbishment 2.12 Passive and Active Ventilation 30
schemes and we would be delighted to have input into, and to receive feedback on, your own
2.13 Comfort Cooling 32
projects.
2.14 Upgrading a Roof or Building a Mansard 34
2.15 Thermally Upgrading the External Walls 36
2.16 Holistic Sustainable Refurbishment 38
3.0 Standards and Regulations 41
3.1 Grosvenor’s Approvals Process 42
3.2 Planning and Listed Buildings Consent 44
3.3 Building Regulations Part L1B 45
Nigel Hughes, FRICS 3.4 BREEAM Domestic Refurbishment 46
3.5 Government Funding: Green Deal 46
The Estate Surveyor, Grosvenor
4.0 Appendices 47
January 2013 4.1 Further Reading 48
4.2 Glossary 50
4.3 Sustainability Questionnaire 53
2 3
Sustainable Refurbishment: a Toolkit for Going Green The Benefits of Refurbishment
Typical refurbishment: Going green:
insulation
prevents heat
loss through
seasonal roof uniform
variation in temperature
temperature across rooms
hot water
harmful hot water cylinder
emissions from cylinder with connected to
carpets and immersion solar water
paint heater heating panel
on roof
condensation
on internal
uneven surfaces
temperatures heat retained
draughts
across rooms by double or
excluded and
secondary
cold spots ventilation
glazing
caused by heat provided by
loss through trickle vents
chilly draughts single-glazing
through old
window/door
frames
noise
unstable noise prevention by
heating with pollution double or sec-
ineffective oc- effective ondary glazing
through
cupant control controls to
single-glazing
heat sources
efficient,
responsive
slow delivery boiler and
of hot water plumbing
to taps caused system
heat lost
by inefficient
through un-in- heat retained
boiler and pipe
sulated walls by solid wall
system
insulation
The sketch above is intended to demonstrate the potential pitfalls to occupant comfort when a refurbishment comprises only This second sketch demonstrates the enhanced environment that can be created through a carefully planned and managed
minimal interventions to fabric, and where the original services are retained. Inefficient old buildings are of primary concern, sustainable refurbishment. Unwanted noise, draughts and cold spots are eliminated through high quality building fabric.
especially where existing single-glazed windows are not upgraded as this can allow for draughts and cold spots. Noise pollution, Occupant control over internal temperatures is provided through thermostats and local controls. Services have been upgraded
lack of occupant control over internal temperatures and the presence of harmful emissions from fabrics and finishes are also to incorporate efficient appliances and renewable technologies, thus reducing the overall energy demand of the home.
common problems.
4 5
1.0 Executive Summary
1 Introduction
Refurbishments to properties present ideal opportunities to take advantage of sustainable
technologies that not only improve the environmental performance of a building but
also benefit the occupants in terms of thermal comfort, user control, lighting, acoustics,
aesthetics, health considerations and financial value. The aim of this document is to inform
residents of Grosvenor’s London estate of the key sustainable measures to consider when
undertaking residential refurbishments.
The document is broken down into a ‘toolkit’, with advice specific to building elements
such as windows and walls, as well as lighting or electrical systems. For each element,
design considerations and sustainable product solutions are provided, incorporating best
practice guidelines for sourcing where relevant. Case studies describing Grosvenor schemes
that have taken advantage of sustainable solutions have also been provided, to convey an
understanding of how these can be implemented in historic properties within conservation
areas such as Mayfair and Belgravia.
For a site-specific solution, design development with qualified professionals is necessary
to ensure that the approach is appropriate to the location and site-specific factors such as
occupant profile and historic features. The refurbishment of residential property on the
estate is also subject to the Grosvenor approvals process as well as a large number of local
and national regulations, the most relevant of which are outlined in the appendices at the
end of the guide. A glossary and references to relevant publications have been provided, as
well as a description of BREEAM Domestic Refurbishment, a widely recognised certification
scheme for sustainable projects.
This document is to be treated as a guide only; it is not prescriptive. Its employment does not
guarantee approval of alterations from Grosvenor or any other statutory body. Grosvenor
does not take any responsibility for the effectiveness of measures outlined in this guidance
document.
Belgravia
6 7
Sustainable Refurbishment: a Toolkit for Going Green 2.0 Aspects of Refurbishment
2
Introduction
Aspects of
Refurbishment
The following section is broken down into the key elements of refurbishment and describes
Aspects of refurbishment contents:
Upgrading a Roof or
the opportunities available for making improvements that will benefit the occupant and Building a Mansard
34 Comfort Cooling 32
improve the environmental performance of the building. For each topic (see opposite), a
flow chart of considerations is provided, leading to a set of product solutions where relevant.
In some instances, permission from the Local Authority is required for undertaking certain
works; this has been highlighted where applicable. With respect to listed buildings, the Local
Authority treats each case on merit and it is important to consult with the local planning
officer when making alterations beyond simple cosmetic maintenance. Upgrading the Heating Passive and Active
and Plumbing Systems 16 Ventilation 30
Where appropriate, the options have been split into ‘passive’ and ‘active’ measures. ‘Passive’
measures are changes to the building that can generally work without an energy supply, such
as insulation; ‘active’ measures usually require a form of energy to function, such as a gas
boiler and radiators. It is often preferable to implement passive measures first, as this will
enable the building to stabilise and self-regulate, as opposed to relying heavily on an active Upgrading Windows in Upgrading Water
a Listed Property 26 Fittings 18
energy source.
Case Studies The case studies have been included to provide examples of where sustainable measures
have been incorporated into refurbishment works. Some are located on the Grosvenor estate
and have achieved certification under the BREEAM or EcoHomes environmental assessment
scheme, a description of which can be found on page 45. Others are located in historic Upgrading the Lighting Windows in a Con-
environments elsewhere in London. The case studies are located on the following pages: and Electricals 10 servation Area 24
12 Wilton Mews 10
11 Grosvenor Crescent Mews 12, 18, 23
15 Passmore Street 14, 16
Insulated roof space 20 Choosing a Redecorating and
Contractor
20 Choosing Materials 12
Heritage Windows 22
117E Eaton Square 23
147 & 149 Ebury Street 24
Secondary glazing 26
100 Princedale Road 28
Holistic Sustainable Thermally Upgrading
3-10 Grosvenor Crescent 32 Refurbishment 38 the External Walls 36
58 Park Street 36
10 Hawthorn Road 40
120 Mount Street 41
The sketch above lists the pages covering the key aspects of refurbishment in the report. Interspersed within these are case studies
of various Grosvenor and non-Grosvenor properties.
8 9
Sustainable Refurbishment: a Toolkit for Going Green 2.1 Upgrading the Lighting and Electrical Systems
Upgrading the lighting When upgrading the lighting and electrical systems,
what measures can be implemented to provide
and electrical systems occupant benefit and save energy?
Passive measures:
i
Lighting and electrical solutions have evolved rapidly, such that there are now systems that
not only allow for greater user control of lighting, but also create brighter and warmer living 1 2 3
environments that use far less energy than conventional circuits.
Using daylight Monitor usage Smart controls
?
Myth: Switching lights on and off uses more energy than leaving them running.
Fact: Switching on an energy saving bulb only uses the same amount of power as leaving Aside from saving energy, daylight Real time electricity consumption Introducing a central switching
it on for a minute or two. Turning the bulb on and off repeatedly may shorten its life, is known to have a positive can be easily determined through unit for the household lighting
but normal household use shouldn’t cause any adverse effects. Energy Saving Trust impact on health and wellbeing. the installation of a fixed energy and electrical system can allow
recommended bulbs are tested through thousands of cycles of switching. It is possible to optimise daylight monitor in a visible location within increased occupant-control over
levels by painting window sills and the property: lighting and energy as well as
!
When working with electrical wiring and the skills of a qualified professional can be sought openings white and by ensuring reducing waste levels. These
for complex tasks involving live circuitry. Part P of the UK Building Regulations covers window openings are free from Devices can display current and ‘power down’ switches can be
Electrical Safety, as do the Electricity Safety, Quality and Continuity Regulations 2002. obstruction. Consider installing historic energy use in kilowatt- located at the front door, to
conservation style roof lights hours, as well as current and enable users to turn off non-
to bring daylight into stairwells projected costs and associated essential electricals when exiting
and roof spaces and using light levels of carbon emission. the home, leaving important
reflecting paint on walls to reduce Packages are now available that appliances such as fridges and
the need for electrical lighting. also allow users to view their freezers on.
consumption data online.
The living room at 12 Wilton Mews
benefits from LED lighting, which is Active measures:
both energy efficient and effective
at producing a comfortable light.
Lighting levels are controlled via an
iPad app.
4 5 6
Replacement of Get the right mix Efficient appliances
lighting
Choose lighting carefully, or consult The EU Energy Efficiency label
Consider replacing traditional a lighting designer to ensure the gives information on a product’s
household bulbs with high right combination of task, feature performance, with a rating
performance, energy efficient and ambient lighting is created. from A+++ to D. Best practice
alternatives. appliances come with the
Look for products with a colour following ratings:
Traditional filament bulbs and rendering index (CRI) of 80+ for a
halogens can easily be replaced warm light in living and bedrooms, Fridge-freezers: A++
with highly efficient LED lamps, and around 70 for a cooler light in Dishwashers: A+
which emit between 60 and 70 kitchens and bathrooms. On light Washing machines: A+++
lumens per Watt. These products bulb packaging this information is Washer-dryers: A
give the same colour rendering displayed as a colour scale, with an Dryers: A
and dimmability of traditional indicator showing the Kelvin value Ovens: A
bulbs, but use much less power. of the bulb. The lower this value, Microwave: A
the warmer the light.
10 11
Sustainable Refurbishment: a Toolkit for Going Green 2.2 Redecorating and Choosing Materials
Redecorating and When redecorating and choosing materials, what
environmental standards are available to set the bar for
Choosing Materials sourcing materials and products?
Internal finishes:
i
Current supply-chains mean that products are available that not only accommodate personal
taste but also minimise environmental impacts; an example of this is the wide availability of 1 2 3
sustainably-sourced timber. In addition, modern labelling conventions can enable consumer-
awareness of the presence of potentially harmful Volatile Organic Compounds (VOCs). Paint Floor finishes Joinery
Microporous paints are ideal for Select floor finishes made from Timber finishes and furniture that
?
Repair and renewal works do not normally require consent from Grosvenor where identical use in older houses where they natural or recycled materials come FSC (Forest Stewardship
materials and finishes are being used. Minor alterations including new kitchens, bathrooms will help prevent high internal and that have a low VOC content. Council) or PEFC (Programme
and cupboards are also exempt from the approvals process. moisture levels. They are also safe Low-VOC adhesives are also widely for the Endorsement of Forest
for use in children’s and family available. Certification) certified are
!
For listed buildings, permission is required for any internal works beyond simple rooms due to their low VOC (see sourced legally and sustainably.
redecoration. The removal or alteration of historic features such as panelling, cornicing glossary) content. Natural coverings made from Where MDF (Medium Density
or ceiling roses is generally prohibited and their maintenance should be carried out by an wool, coir, jute and seagrass are Fibreboard), plywood or particle
experienced professional. In addition, Grosvenor’s External Appearance Policy outlines the Consider both plant-based water- among the best available options. board is used in joinery, specify
requirements for external paint finishes on the estate; see page 42 for more information. borne and plant-based solvent Consider those which demonstrate products that have low VOC
borne paints for best results. quantifiable environmental data, contents and are pre-cut to avoid
These paints can also be used for based on ISO 14040:2006. Note high levels of dust or harmful
woodwork and metal. that where synthetic materials are irritants inside the property.
used, VOC emissions from finishes
and adhesives are at their highest
in the days immediately following
installation.
The staircase at 11 Grosvenor
Crescent Mews was manufactured
from FSC (Forest Stewardship
Council) certified timber. The
Structural materials:
contractor was required to supply
proof of sourcing in the form of a
receipt specific to the staircase, 4 5 6
documenting its FSC certification
from source to supply. Timber Concrete Stone
When specifying timber products, The carbon emissions associated Consider purchasing recycled/
it is possible to ensure it comes with concrete production can reclaimed stone for use as a
from legal and sustainable be reduced through various building material within the
sources by requesting a copy of measures: structure of an extension or
the Chain of Custody Certificate rebuild, or as a finishing material
from the contractor. Concrete that uses recycled either internally or externally.
aggregates is a lower carbon
This certificate is the paperwork option than that which uses virgin Recycled aggregates are ideal
which traces the handling of aggregates. In addition, industrial as a sub-base for larger building
the timber back to its origin, by-products such as fly-ash from projects and have the same
through the various stages of power stations can be used in properties as freshly extracted
felling, manufacturing, sales and concrete mixes as a cement minerals. Often, reclaimation yards
distribution, and proves that the replacement product, for example or architectural salvage companies
timber was sourced legally. GGBS or PFA. offer reclaimed stone products.
12 13
Sustainable Refurbishment: a Toolkit for Going Green 2.3 Case Study: 15 Passmore Street
Case Study: The rear extension at 15 Passmore
Street benefits from high
15 Passmore Street
performance insulation, double
glazed doors and a skylight. A water
butt collects rainwater for use
within the garden.
Client or developer: Grosvenor Britain & Ireland
Architect: GRA Architecture
Contractor: Grangewood
Environmental Consultant: Eight Associates
“The higher quality
This terraced house on Passmore Street has achieved an ‘Excellent’ EcoHomes rating (see
glossary). The scheme benefits from secondary glazing to the front windows and extensive
insulation keeps it
insulation to the roof, where eight photovoltaic (PV) panels are also sited to generate a cool in the summer
substantial amount of the household’s electricity.
and warm in the
Lighting and appliances were carefully selected to marry comfort and energy efficiency. The
luxurious sanitaryware is water-efficient and a discrete water butt collects rainwater for use winter.”
in the garden.
All the timber used on site was responsibly sourced and certified by the FSC. In addition, the
contractor diverted 95% of waste from landfill by recycling or re-using ‘waste’ materials on
nearby sites.
-resident of 15 Passmore Street
The image below shows the discrete location of the photovoltaic panels on the roof of the
property, carefully angled to optimise their exposure to the sun.
Eight photovoltaic panels mounted The flooring in the living area of 15
on the roof of 15 Passmore Street Passmore Street was constructed
have generated 1000 kWh of using FSC-certified timber. Energy
electricity worth £460 in one year, efficient LED lighting was used to
saving 591 kilograms of carbon create a soft, warm glow and paints
dioxide. and varnishes from Dulux contained
low levels of VOCs.
“Grosvenor
implemented
green solutions
throughout the
house including “It also makes
solar panels, LED me feel good to
lights and energy reduce my carbon
saving exhaust footprint.”
fans.”
-resident of 15 Passmore Street -resident of 15 Passmore Street
14 15
Sustainable Refurbishment: a Toolkit for Going Green 2.4 Upgrading the Heating and Plumbing Systems
Upgrading the Heating If changes are being made to the heating and plumbing
systems, what are the opportunities for making
and Plumbing Systems environmental improvements?
i
Eventually, central heating systems need replacing due to the installation of new pipework
alongside old and tinkering over time. When replacing boilers and pipework, it is possible 1 2 3
to implement measures that give greater user control of temperatures in rooms, as well as
improving the efficiency of the overall system. Reducing demand Insulating hot water Walls, floors and roof
elements alterations
?
Central heating is a post-war invention. In 1955, only 5% of UK homes had central heating There are a number of passive
systems. By 1975, central heating was present in 50% of homes and in 2001, the figure stood measures that can be introduced
at over 90% (source: BRE report BR435, 2001). without building works to reduce Think about adding insulation to If considering more invasive work
heat loss. Consider installing hot water cylinders and pipework as part of a refurbishment such as
! The addition of a boiler flue constitutes an alteration to the external appearance of a building draught-proofing to windows, to make sure heat is only being structural alterations, investigate
in a conservation area. Planning permission from the Local Authority is required for new doors and chimneys and fitting delivered where it is needed, the possibility of upgrading
boiler flues, as is direct consent from Grosvenor. draught excluders to letter boxes reducing levels of wasted energy. windows or installing insulation
to retain heat and reduce the to walls, floors and roofs in
need for central heating. Installing a 75mm thick insulating order to improve the property’s
jacket to the hot water cylinder overall thermal performance. See
and insulating direct hot water sections 2.8, 2.9, 2.14 and 2.15 for
pipework will cut heat loss and further information.
reduce waiting times for hot water
to be delivered to the taps.
This flat at 1 Lochmore House,
Cundy Street, implemented a
greywater recycling system that
purifies and stores water from
the wash-hand basin and showers
for use in the WC. In addition, the
4 5 6
internal walls are insulated to
reduce heat loss. The specification
Metering Controls Replacement
included further water efficiency
and energy efficiency measures. It is possible to install heat meters Look into improving heating controls Consider replacing the existing
PV panels on the roof provide to the gas supply. This will allow to ensure heat is being generated at boiler with an A-rated condensing
electricity to the communal parts of monitoring of usage over time and the right time of day and the right system boiler, or for small
the building. The scheme achieved identify any periods of unusually zones/floors for the occupants. In properties, a combi-bolier to supply
an EcoHomes ‘Excellent’ rating.
high consumption, which could addition, consider having the hot water on-demand. At the same
indicate a leak or fault within the heating system serviced by a Gas time, consider installing solar water
system. Energy monitors will also Safe registered engineer to ensure heating panels to the roof; these
serve to verify that the energy that it is functioning correctly and connect to the hot water tank and
company’s meter is functioning that no energy is being wasted. can provide a significant portion of
correctly. a household’s hot water demand.
Controls such as Thermostatic
Devices can display current Radiator Valves (TRVs) or Choose a boiler with an efficiency
and projected consumption programmable room thermostats of at least 87% and Nitrous Oxide
and associated levels of carbon ensure constant heating levels that (NOX) emissions of less than 50 mg/
emission. are tailored to each room. kWh.
16 17
Sustainable Refurbishment: a Toolkit for Going Green 2.5 Upgrading Water Fittings
Upgrading If upgrading water fittings, what efficient
measures can be implemented without compromising
Water Fittings comfort?
Water efficiency:
i
A common expectation is that water efficiency is compromised by the requirements of
high quality bathrooms. By combining carefully chosen sanitaryware and appliances that 1 2 3
incorporate water-saving technologies, together with sensible occupant usage, the needs for
both comfort and water efficiency can be satisfied. Taps & showers WCs Domestic appliances
?
Reducing water at the point of use is much better for the environment than trying to treat it Consider selecting water efficient Low flush/dual flush WCs reduce When replacing appliances,
afterwards. In the UK we use an average of 150 litres of drinking-quality water, per person, products for sinks and showers. the average volume of water consider water efficient products
per day. This equates to just under 274,000 litres a year for a family of five! used for flushing. Alternatively, recognised by the Energy Saving
A five minute power shower can use installing a cistern displacement Trust Recommended labelling
! Part G of the UK Building Regulations is the section concerned with water efficiency, as well as much water as an average bath. device in an existing WC will save scheme.
as sanitation and hot water safety. For new properties, the document stipulates that water Efficient, aerated shower heads on average 1-2 litres per flush.
use should not exceed 125 litres per person, per day. Special consideration is given to listed can have a flow rate of as little as 9 Recommended washing
buildings and those within conservation areas such as Mayfair and Belgravia however, where litres per minute (even with a large Low flush/dual flush WCs enable a machines can have a maximum
the aim should be to improve sanitation and hot water safety as far as possible without showerhead of 240mm diameter), lower flushing volume of 3 litres, consumption of 40 litres per
adversely affecting the property’s appearance or historic significance. compared to 18 litres for a as well as the standard 6 litres of cycle. Recommended dishwashers
traditional fitting. Aerated, low flow non-dual flush models. can use a maximum of 12 litres
taps can have a flow rate of as little per cycle for a standard sized
as 5 litres per minute, compared to machine; this can be over 85%
12 litres for a traditional tap. less than hand washing.
Water efficiency measures at this
high-end bathroom at 11 Grosvenor Water supply:
Cresecent Mews include an efficient
aerated shower from Hansgrohe, a
low flow dual flush WC and aerated 4 5 6
taps with flow limiters.
Water butts Water recycling Water metering
Where properties feature external More advanced forms of water To monitor water consumption,
space, rainwater can be collected recycling can provide sufficient a water meter can usually be
for external irrigation by attaching water for a large portion of internal, installed by the water company in
a water butt to the downpipe of a as well as external use. ‘Greywater’ a visible location in the property.
property’s guttering. systems use waste water from the Water meters provide a visible
bath, shower and wash hand basin, display of water consumption to
Water butts can have a capacity and redistribute it to non-drinking allow levels to be monitored over
of between 100 and 200 litres, water outlets such as WC flushing, time. They can display the volume
dependent on the size of the area plant irrigation and clothes washing. of water used instantaneously or
to be irrigated. Units can lie flat historically at 30 minute intervals.
against a wall, or be located within Rainwater systems are preferable to
a planter. As well as plant irrigation, greywater, as these use disinfectants Note that installation of a water
the water can be used for car which can overburden the sewage meter may have an effect on the
washing and cleaning outdoor areas. system. tarriff used to determine bills.
18 19Sustainable Refurbishment: a Toolkit for Going Green 2.6 Choosing a Contractor
Choosing a When choosing a contractor, what are the points to
look out for and what environmental standards can be
Contractor requested of them?
Design stages:
i As a potential client, it is possible to choose the contractor who will undertake the building
works based on their track record for environmental awareness and experience. In addition, 1 2 3
requirements can be placed on the contractor to reduce wastage, recycle, and minimise
energy and water usage, all of which will have a positive financial impact on the scheme. Initial questions Assess experience Third party audit
Consider writing up a list of At the same time look at the Consider contractors who are
?
In March 2012, the UK construction industry employed around 2.04 million people; equivalent
questions to ask potential portfolio of work of potential registered with the Considerate
to around 6.4% of all workforce jobs nationwide. Of the contracts that create this level of
contractors at the initial stages. contractors, to assess their Constructors Scheme. The
employment, around a fifth came from private housing projects, such as the refurbishments
These might include the following: expertise/experience in CCS is an independent, not-
we are concerned with in this document.
conducting sustainable for-profit organisation, whose
How... refurbishments. For example, code of practice covers
! Since 2008, it has been a legal requirement that all contracts in England with a value of over
£300,000 have a Site Waste Management Plan (SWMP) in place. For those over £500,000
• Do they minimise/recycle
demolition and site waste?
those with relevant experience in
sustainable refurbishments may
environmental considerations,
as well as management,
a more detailed set of procedures is required. The implementation of SWMPs ensures that • Do they take steps to prevent have worked on insulating solid- efficiency and neighbourliness.
waste is dealt with in a responsible manner, thereby reducing the cost of waste disposal and pollution? walled houses, or on new-build Where contractors are not
subsequent levels of fly-tipping. See the section on Waste Management opposite for more • Do they operate an sustainable projects. registered themselves, the site
information. Environmental Management can be registered before the
System (EMS) such as ISO 14001? commencement of works with the
• Do they employ local labour? same implications.
How do they train their staff to be
environmentally responsible?
An example of an insulated roof
space. The area is kept tidy, with
well-placed wiring and materials.
Construction requirements:
4 5 6
Best practice Waste management Commissioning and
testing
It is possible to make sure Contractors are legally required to
contractors are following best produce a Site Waste Management
practice pollution prevention Plan (SWMP) to show which Following completion, the
guidelines by looking at guidance materials are being sent to ‘as-built’ performance of the
from the Environment Agency. landfill, and which are being re- project can be tested to ensure
used and recycled. projected levels of efficiency
Their publication ‘Working at are being achieved. Proper
Construction and Demolition Request that at least 85% of commissioning of services,
Sites’, PPG6, details the steps waste is diverted from landfill followed by airtightness testing,
that can be taken to ensure and re-used or recycled. This and thermographic imaging
minimal risks to health and can be reviewed by an assessor will ensure the correct settings
the environment. This includes during the course of site works and demonstrate the building’s
reporting on energy and water by requesting for the site waste performance.
usage during site works. management plan every 2-3
months, a legal requirement on all
projects.
20 21Sustainable Refurbishment: a Toolkit for Going Green 2.7 Case Study: Heritage Windows 2.8 Case Study: 117 Eaton Square
Case Study: Draught-proofing
The diagram to the right
Heritage Windows demonstrates the location of
draught-proofing within a traditional
timber sash window. 2
The first image shows the location
of the detail, highlighted in green.
Client: Grosvenor Britain & Ireland The detail to the right shows the
Architect: David Morley Architects location of draught-proofing both
Contractor: Grangewood
Sustainability Consultant: Eight Associates
within the upper bar of the lower
sash at mid-rail, and a weatherfin 1
set within the sash box itself.
The window of a ground floor room of this mid-terrace Georgian property has been upgraded 1. Location of detail within the
with three different types of glazing: single glazing with new panes, slimline double glazing sash window
and vacuum double glazing, in order to compare their performance in a heritage setting. 2. Location of fin set into
The large image below shows the thermal performance of the three types of glazing. The
window frame between sliding
elements
3
single glazing (1) has the brightest colour, signifying higher heat transmittance therefore 3. Location of mid-rail brush
a greater degree of heat loss. The double glazing systems, (2) and (3) have darker colours
indicating lower heat losses than the single glazing. The smaller images below left show
the window before refurbishment, the surface temperature readings of the glazing and the
window in its surrounding context.
The top floor apartment at 117E
Eaton Square benefited from a
range of environmental upgrades,
include extensive draught-proofing
1 to the windows using the Ventrolla
perimeter sealing system.
3
2
22 23Sustainable Refurbishment: a Toolkit for Going Green 2.9 Upgrading Windows in a Conservation Area
Upgrading Windows in a If upgrading the windows in a conservation area, what
are the design considerations and consequent options?
Conservation Area
Design considerations:
i Windows play a vital role in buildings by providing natural light and acting as the main source
of fresh air. However, their noise and heat loss properties create potential weak spots in the 1 2 3
building with regards to occupant comfort. Windows are also a vital part of historic streetscapes;
upgrading them with regard to their heritage context is vital and consultation with the Local Understand the Identify criteria Ventilation
Planning Authority is required before making changes.
location
What are the main reasons In comparison to new buildings,
?
It is possible to determine the approximate age of Georgian terraced houses by the position for upgrading the windows? traditional buildings typically
of the sash windows within the brickwork. Those with a visible sash box (outer frame) which is Mayfair and Belgravia are Possible selection criteria can require greater levels of air
flush with the facade were generally built before 1709, after which time the building regulations both conservation areas and include: acoustic properties, infiltration to deliver fresh air
prescribed that windows should be set back by 4 inches, as this would help prevent the spread of thus have their own specific heat loss properties, security and remove moisture. Replacing
fire. A further revision to the regulations in 1774 required the sash box to be hidden behind the planning restrictions. It is considerations, openability and traditional, single-glazed windows
brickwork altogether; these examples also tend to exhibit thinner glazing bars. important therefore to gain aesthetic appearance. Solutions with double-glazing can reduce
an understanding of local can be tailored according to these the ability of air to permeate the
characteristics and to evaluate
!
For flats or maisonettes in a non-listed building within a conservation area, planning permission priorities. external envelope. Where this is
will be required for alterations where the appearance of the building is affected. Double glazing the condition of existing windows the case, double-glazing which
is permitted development for unlisted houses, although confirmation is to be sought from the both on the property and in the incorporates trickle vents in the
Local Authority prior to commencement, and Grosvenor approval will be required. Replacement surrounding area, to gain an frame can be installed, which can
windows within existing brickwork should be timber-framed, and the glazing bars should match awareness of suitable solutions. provide a low level of ‘background’
the pattern of the original windows. ventilation.
Achieving an EcoHomes ‘Very Good’
rating, the scheme at 147 and 149
Product solutions:
Ebury Street saw the upgrading
of windows to the main elevation.
Where windows were retained, Slimline double glazing
secondary glazing was applied to
the interior surface to reduce heat These units are constructed using narrower spaces (between the two panes of glass) than standard double glazing units and
loss and noise pollution. are an effective solution for achieving high thermal and acoustic performance standards within a heritage context.
Glazing with an air gap of 3mm can achieve a thermal transmittance, or ‘U-Value’ of 1.4W/m2K; a value similar to that of a
standard wide-framed, double glazed unit. Note that the lower the U-Value, the better its insulating properties.
Slimline double glazing in existing frames
This option uses the same slim double glazing as the previous option, but individual panes are inserted into existing frames
without noticeably changing the appearance of the glazing bars. This is a high-performance option for situations where the
existing frames are to be retained, although the sashes may require re-balancing with additional weights.
Systems of this kind typically achieve U-Values of 1.9W/m2K.
Triple glazing
High specification triple glazing can reduce heat loss by up to a third in comparison with double glazing, as well as providing
excellent acoustic properties. These units use three panes of glass and two air gaps filled with an inert gas such as argon to
achieve the best possible insulating properties whilst still allowing high levels of daylight into the property. Currently, this
solution is unlikely to be approved on the Grosvenor estate, but may be allowable in some instances.
High performing triple glazing will typically achieve a U-Value of 0.8W/m2K or below.
24 25Sustainable Refurbishment: a Toolkit for Going Green 2.10 Upgrading Windows of a Listed Property
Upgrading Windows If upgrading the windows of a listed property, what are
the additional design considerations and consequent
of a Listed Property options?
Design considerations:
i It is recognised that listed buildings used for residential purposes will change over time as
opposed to monuments that will be preserved as far as possible in their existing state. On 1 2 3
this basis, it is possible to upgrade windows and enjoy the associated benefits, in conjunction
with respecting and conserving the historic environment. Planning requirements Secondary glazing Identify criteria
? The UK’s oldest functioning window frame is estimated to have been constructed around a
thousand years ago. Located in the wall of a Saxon church in Berkshire, the window had been
In general, secondary glazing is
the only alteration to windows
Secondary
glazing retains
Consider the range of secondary
glazing options and identify the
concealed by Victorian renovations until it was discovered by a workman in 2010. permissible in listed properties. the original attachment mechanism that is
Other options for the rear such as single glazing, most suitable for the property.
! Listed building consent must be sought from the Local Authority to legally proceed with the double glazing may be possible in whilst giving Important questions to ask are:
installation of secondary glazing, and approval from Grosvenor is also required. This is looked some circumstances, depending the thermal do the windows remain openable
on favourably in a residential context so long as the glazing bars/divisions on the secondary on the condition of nearby performance of for fresh air? Do the shutters
glazing system align with those of the existing window. Currently, replacement with double properties. Contact the local double glazing. maintain functionality or are
glazing is accepted only in special cases, and is generally not permissible on listed properties. planning officer for site-specific Its installation they permanently closed? Do
guidance on what is allowable. also negates the windows exhibit any unique
the need for features such as ironmongery that
draught- will obstruct secondary glazing?
proofing, as systems are made to
fit the existing frames perfectly.
The image to the right demonstrates
how secondary glazing is designed
to match the pattern of glazing
Product solutions:
bars on the original, single-glazed
window. In this case, the secondary
glazing itself is double-glazed to
ensure maximum insulation from Draught-proofing
noise and protection against heat The simplest and least invasive method of upgrading listed windows is by installing draught-proofing. This can take the
loss. form of removable products attached to the beading, or permanent ‘brushes’ fitted to the inside of the frame opening by
way of grooves routed into the timber. Products can also be sourced and fitted to doors, letter boxes and other openings to
increase comfort and reduce heating demand. Avoid self-adhesive draught-proofing as this comes off very easily.
Removable secondary glazing
Secondary glazing refers to the installation of an additional layer of transparent material behind the existing window pane.
Where conservation issues prevent nails or screws being used to attach systems to the window frame itself, removable
panes can be applied using magnetic strips or other adhesive, and can be used during the winter months and removed
when the weather gets warmer.
Fixed secondary glazing
Where allowable, secondary glazing can be fixed using nails or screws to the sash box or beading of a window, and can be
single or double glazed. Systems can be designed so that the rails and bars align with the existing window, preserving the
external appearance and giving high thermal performance values.
26 27Sustainable Refurbishment: a Toolkit for Going Green 2.11 Case Study: 100 Princedale Road
Case Study:
100 Princedale Road
Post-occupancy monitoring at Princedale Road
Client and developer: Octavia Housing
Architect: Paul Davis and Partners
Contractor: Princedale EcoHaus
Sustainability Consultant: Eight Associates
An exemplar sustainable refurbishment, this pre-1919 terraced house in Holland Park has
achieved Passivhaus certification, a comfort-based energy assessment. The family of four
who currently occupy the property benefit from a 70% reduction in energy bills and excellent
thermal comfort levels.
The building is fully insulated and triple glazing has been installed. The house’s fresh
air passes through an underground heat exchanger, where it is preheated or pre-cooled
depending on the season, and is then filtered before being distributed to each room,
ensuring a stable internal temperature.
There are three solar thermal panels on the roof that provide 80% of the direct hot water for
showering, baths and washing up. The building is in a conservation area and the key element
to negotiate with the Local Authority was the triple glazing. These are designed to match the
appearance of the existing windows when closed.
100 and 102 Princedale Road where
families in the houses benefit from
insulation and upgraded windows
to the whole of the house. These
measures have been implemented
without significantly altering the
appearance of the streetscape.
A study was conducted on Princedale Road, examining the performance of three houses of
similar geometry and occupancy, each refurbished to a different standard. These included a
‘typical scheme’ (above in grey) which met current Building Regulations but went no further,
a Decent Homes Plus standard refurbishment (above in yellow) which took insulation and
airtightness considerations into account, and the aforementioned Passivhaus scheme, displayed
in green.
It was found that the Passivhaus performed better than the Decent Homes Plus and the typical
scheme in multiple ways, including water and energy use, thermal comfort and indoor air quality.
Final energy demand was reduced by 83% in the Passivhaus and 46% in the Decent Homes Plus
scheme in comparison to the typical scheme.
The carbon emission performance of the Passivhaus scheme achieved 60% less than the control
scheme or Typical Scheme with no significant measures. The energy bills were 60% lower in the
Passivhaus and the thermal comfort benefits were significant – the average internal temperature
during the winter months in the Passivhaus was 20.8 degrees compared to 16.4 degrees in the
Typical Scheme.
28 29Sustainable Refurbishment: a Toolkit for Going Green 2.12 Passive and Active Ventilation
What opportunities are there for effectively providing
Passive and fresh air to living spaces?
Active Ventilation
Passive measures:
1 2 3
i A supply of fresh air is important to the well-being of building occupants, particularly during
the summer when temperatures are high, but also during winter when inside air can become
Single-sided and cross- Trickle ventilation Passive stack ventilation
stale. There are a number of options for bringing fresh air inside. Mechanical Ventilation with
Heat Recovery (MVHR) is an advanced, low energy system which ensures constant internal ventilation (PSV)
temperatures. Where windows are being
replaced, consider installing
Ensuring a clear passage of air A PSV system draws air through
?
One of the very first ‘forced air’ ventilation systems is still in existence at St. George’s Hall in frames with built-in trickle vents,
through opening windows on the house by means of wind cowls
Liverpool. Designed by Scottish scientist and inventor David Boswell Reid, the system used which are an effective means of
two sides of a property may installed on the roof, which ‘pull’
coke and steam-fired boilers to warm and circulate fresh air through a series of ducts and supplying background ventilation
provide adequate ventilation. stale air out of the house through
tunnels, hidden within the building’s floor and walls. where rooms are already fitted
Where the building has only one ducts in the walls and ceilings, to
with sealed chimneys, new doors
aspect, sash windows which open be replaced with fresh air drawn
! Standards regarding levels of ventilation are covered by Part F of the UK Building
Regulations. Where work is being done to historic buildings and those within conservation
top and bottom allow a certain
degree of control. This is useful
and double glazing. It should be
noted that while this measure
in through vents in the walls
without the need for electricity. In
areas, the aim should be to improve ventilation levels as far as reasonably possible with is compatible with Continuous
in evacuating water vapour from historic buildings these systems
regards to the property’s significance. Guidance can be sought from English Heritage and Mechanical Extract (see below),
kitchens and bathrooms quickly can be integrated with existing
through the BS 7913 document Principles of the Conservation of Historic Buildings in the trickle vents will reduce the
(see opposite). chimney flues, and the cowl made
development of appropriate ventilation strategies. effectiveness of Mechanical
to resemble a traditional chimney
Ventilation with Heat Recovery.
pot.
Where a room has windows on more
than one side, these can be opened Active measures:
to take advantage of wind-driven
cross-ventilation. This is particularly
useful on upper floors, where open wind
direction
4 5 6
windows will provide an easy route
for air to move through the building. Mechanical extract Continuous mechanical Mechanical ventilation
(ME) extract (CME) with heat recovery
fresh air
replaces stale air (MVHR)
Mechanically driven, localised This system uses an ‘always on’,
ventilation is particularly beneficial centrally located ventilator to
in areas such as kitchens and draw fresh air in through trickle This system uses a centrally
bathrooms, where it removes vents in the building’s external located unit to transfer the heat
Although not quite as effective as high levels of moisture and other envelope, expelling the exhaust from extracted air to incoming
cross-ventilation, rooms with only pollutants. Systems can be manually air through ducting in the roof fresh air, thereby creating a
one aspect can use single-sided
controlled or automated, tiggered by and walls. CME can be combined pleasant environment with a
ventilation for the delivery of fresh constant internal temperature.
air. Opening both top and bottom heat, pollutant or humidity sensors. with Passive Stack to create an
sashes will allow for air circulation; sash windows ‘Assisted Passive Stack Ventilation’
To comply with building regulations system, where the mechanical Domestic heat exchangers
on warmer days buoyancy will open top and
bottom extractors in kitchens should be unit is activated when wind levels can have an efficiency of
encourage air movement.
capable of drawing air out at a are too low to be effective. 88%, meaning the majority of
rate of 30 litres per second. For exhausted heat is recovered
bathrooms this is 15 litres per by the unit for the purpose of
second. warming the incoming air.
30 31Sustainable Refurbishment: a Toolkit for Going Green 2.13 Comfort Cooling
Comfort Before considering comfort cooling systems, what
opportunities are there to cool naturally?
Cooling
Passive measures:
i The aim of installing comfort cooling is to control internal temperatures for thermal comfort
purposes; typically a user will set a temperature of 21 degrees centigrade, plus or minus 2 1 2 3
degrees, although we would recommend a higher setting on warmer days to reduce energy
consumption. Traditional buildings have variations in temperature depending on external Natural ventilation Shading Passive internal gains
environments that exceed this range by 3 or 4 degrees.
Often a good supply of fresh air Consider restoring existing shutters Consider installing energy
?
Before installing comfort cooling, there are a number of passive measures that can be will be sufficient to cool down an to south-facing windows to block efficient lighting and appliances,
implemented to reduce, or even eliminate the demand for it (see opposite page). Once these interior on warm days. This can heat gains in the summer months. as traditional or outdated
have been addressed, consider installing comfort cooling to the main rooms only, such as be achieved through ensuring Venetian blinds angled so as to installations often emit a lot of
living rooms and bedrooms. In addition, consider using a prominently-placed energy meter to adequate levels of single-sided or block the sun’s rays will have the heat, thus increasing the need
monitor the amount of electricity used. cross-ventilation. See the previous same effect and will also allow a for cooling. In addition, switching
section for more information on degree of daylight into the room. off computing and audio visual
!
Planning permission will be required when installing comfort cooling equipment externally how to make ventilation work In addition, planting trees in back equipment at the wall will prevent
and listed buildings will require consent for any internal alterations. Internal alterations to effectively using sash windows. gardens can block heat gains unwanted heat gains caused while
non-listed buildings in conservation areas are permitted development. A Grosvenor license during the summer, whilst allowing devices are left on standby.
will also be required. light through in the winter when
the leaves have fallen. Note that
external shutters are generally not
allowable on the estate.
Internal shutters at 3-10 Grosvenor
Crescent refurbished and developed Active measures:
by Grosvenor, can be used to keep
direct sunlight out during prolonged
periods of hot weather, thereby
reducing the need for active cooling
4 5 6
within the property. Phase change board System performance External equipment
Phase change material absorbs If you do choose to install a Refrigerant cooling systems
heat energy when the ambient refrigerant cooling system, require equipment to be sited
temperature increases, and consider those which incorporate both in and outside of the
releases it again when the thermostats and time switches property. Close consultation with
temperature falls. At between 5 to ensure it is only used when a design professional can ensure
and 15mm thick, these materials needed. the equipment is located where
can be applied to ceilings, and it will neither cause an adverse
help to maintain a constant Look at units with a high visual impact on the building/
internal temperature during coefficient of performance (COP) surroundings nor contribute to
the summer, when outdoor of 3.5, a low global warming noise pollution.
temperatures can be high. potential (GWP) and a refrigerant
leak detection system.
32 33Sustainable Refurbishment: a Toolkit for Going Green 2.14 Upgrading a Roof or Building a Mansard
Upgrading a Roof When upgrading a roof or building a mansard,
what additional environmental measures can be
or Building a Mansard implemented?
Passive measures:
i
Homes without sufficient insulation lose around a quarter of their heat through the roof.
In addition, inhabitable roof spaces (such as a mansard or loft conversion) can become 1 2 3
uncomfortably warm in the summer months. Installing insulation is an excellent way to
improve a property’s efficiency, resulting in a more stable internal temperature and a Slate reclamation Roof lights Green roofs
reduced reliance on heating sources or comfort cooling.
Retaining original slate or As mentioned in the section These can vary from simple grass/
? The roof can be used as an area to locate renewable energy technologies such as solar
thermal and photovoltaic panels. Although these can be installed in many different
sourcing second-hand tiles from
reclamation yards reduces the
on upgrading the lighting and
electrical systems, roof lights are
sedum coverings to elaborate
roof gardens. Green roofs offer a
orientations, they will work most efficiently when situated on a south-facing roof a a pitch of impact of mining, and preserves an excellent way to bring natural range of advantages, including:
30 degrees, where the sun’s rays are not obstructed by trees or other buildings. the historic character of light into hallways, corridors and improved thermal insulation,
conservation areas. rooms in the roof. Units can be better acoustic properties
! Local Authority advice is required for installation of equipment, which can be an issue for
listed buildings and those within conservation areas such as Mayfair and Belgravia. Listed In addition to slate, reclaimation
installed at both pitched and ‘flat’
orientations, and be operated
and improved rainfall run-off
attenuation, reducing demand
buildings will require permission for alterations of any kind, and planning permission is yards are an excellent source both manually and automatically on drainage systems. They are
required when installing solar panels that add 150mm over the existing building line on a of heritage building elements by switches and rain sensors. also aesthetically pleasing and
non-listed building in a conservation area. such as brick and stone, as Special ‘conservation roof lights’ improve levels of biodiversity.
well as period features such as are available, which are designed Typically, a substrate of 100mm
The diagrams below demonstrate the issues presented by traditional mansard roof porcelainware and ironmongery. to replicate traditional Victorian is required to absorb sufficient
construction, and how these issues can be addressed through good design. units and are more suited to water and allow plants other than
heritage projects. sedum to thrive.
The diagram to the right
demonstrates the design of a Active measures:
traditional mansard roof without
insulation, and with a hot water
cylinder located in the roof space. no loft
insulation
4 5 6
no wall hot water
Air source heat pump Solar thermal panels Photovoltaics (PVs)
insulation cylinder
Air source heat pumps can be These are an effective means of Roof-mounted solar panels can
no floor
used for both heating and cooling supplementing a home’s hot water provide a property with its own on-
insulation the internal environment. As a demand. Water is pumped through site energy supply. An array of cells
heater this technology is able roof-mounted panels where it is convert sunlight into electricity,
to produce several units of heat heated by the sun’s rays before and can even work on cloudy days.
This second diagram demonstrates for every unit of electricity they being passed through a coil in the
how a mansard roof can be consume. Equipment is sited both property’s hot water cylinder. A 15m2 photovoltaic array will
refurbished to incorporate hot water inside the building and outside provide a significant portion
insulation, and how a solar water cylinder con- at roof level. Note also that the 5m2 of solar thermal panels will
loft of the electricity demand of a
heating panel can be used with the nected to solar external equipment generates provide a significant portion of
cylinder, for the provision of hot
insulation three bedroom house. Where the
water heating a degree of noise, and can be the hot water demand of a three
water. panel on roof
generated electricity is not used,
mansard insu- troublesome for neighbours. bedroom house. There are 2
lation
this is exported into the national
types of thermal panel -flat and grid. In addition the owner of the
Consider units with a high evacuated tube; the latter can be
acoustic panels is paid a set number of
coefficient of performance (COP) used where the roof orientation is
floor pence per killowatt hour through
of at least 3.5. not ideal as the fins can be turned
insulation the Feed in Tarriff (see glossary).
towards the sun.
34 35You can also read
