www.islington.gov.uk
Reducing carbon emissions and adapting
to climate change in historic buildings
Guide for Residents
Sustainable Historic Buildings
Guide for Residents
Contents
1.0 Introduction
1
1.1 Climate change and the historic environment
1
1.2 Purpose of this guidance
3
1.3 Planning considerations
4
2.0 How to improve energy efficiency
5
2.1 No cost measures – simple behavioural changes
5
2.2 Low cost measures
5
2.3 Medium cost measures
6
2.4 Larger energy efficiency projects
7
2.4.1 Energy efficient windows (double or secondary glazing)
7
2.4.2 Insulation of walls
10
2.4.3 Upgrade the energy efficiency of your boiler
12
3.0 Renewable energy generation
14
3.1 Solar PV and solar hot water
14
3.2 Ground source heat pumps
16
3.3 Wind turbines
16
4.0 Climate change adaptation measures
18
4.1 Green roofs
19
4.2 Rainwater harvesting
20
4.3 Soft landscaping and permeable paving
21
5.0 Further information
22
Cover image: Front elevation of listed building at Ellington Street with solar panels on rear roof (see back cover).
Sustainable Historic Buildings
Guide for Residents
1.0 Introduction
1.1 Climate change and the historic environment
Climate change is a key environmental challenge. In the UK, 27% of carbon
dioxide (CO2) emissions come from the energy we use to heat, light and
power our homes. Islington Council seeks to secure high standards of
sustainability in all buildings, including by promoting increased energy
efficiency, renewable energy generation and climate change adaptation in
the borough’s existing building stock.
Islington Council is also committed to conserving the borough’s historic
environment, preserving and enhancing the character and appearance of its
Conservation Areas and the special historic and architectural interest of its
Listed Buildings (see box below for definitions). A well managed historic
environment improves the appearance of the built environment and
enhances people’s quality of life by giving a sense of place and promoting
civic pride. From a sustainability perspective reuse and refurbishment of
buildings is beneficial because it avoids the energy and materials
consumption, waste and related construction impacts associated with
demolishing old buildings and constructing new ones. Indeed, historic
buildings such as Victorian houses are often very popular and most of them
are likely to be around for many years to come.
1
Sustainable Historic Buildings
Guide for Residents
While there may be occasions when climate change objectives conflict with
conservation of heritage assets, many opportunities exist for enhancing
energy efficiency, use of renewable energy and improved adaptation to
climate change in historic buildings without negatively impacting on their
conservation value. This approach is supported by the draft Planning Policy
Statement on Planning for the Historic Environment.
What are conservation areas and listed buildings?
Conservation areas are areas of special historical or architectural interest
which have a character that it is desirable to preserve or enhance. In
conservation areas the view of a building from the public realm is
considered the primary concern to ensure that the street scene is
preserved as well as the quality of the architecture. In some
conservation areas ‘Article 4 directions’ place further controls on
development, including on minor alterations or home improvements
such as changing external doors and windows.
Listed Buildings are buildings which are included on the national register
of Buildings of Special Architectural or Historic Interest; they are
protected by law. As such a Listed Building may not be extended or
altered, internally or externally, in any way which may affect its special
character, without Listed Building Consent being approved by the local
planning authority.
2
Sustainable Historic Buildings
Guide for Residents
1.2 Purpose of this guidance
This guidance note outlines approaches and technologies for increasing
energy efficiency (and reducing heating bills), generation of renewable
energy and climate change adaptation that may be suitable for listed
buildings and homes in conservation areas. As this guidance explains, there
are a range of options that can be considered for listed and historic buildings.
Please note however that this guidance is not exhaustive - if you have your
own ideas about bespoke solutions to reduce carbon emissions and better
adapt to climate change while preserving the character and appearance of
conservation areas and/or listed buildings, having regard to the broad
principles set out in this guide, we would be happy to consider them.
Possible approaches and technologies are considered in three sections below:
energy efficiency measures (section 2), energy microgeneration (section 3)
and climate change adaptation measures (section 4).
T-ZERO web tool for comparing green home
improvement options
T-ZERO is a free interactive web-based tool that puts energy and
environmental performance expertise in the hands of the householder. The
tool allows you to identify the optimal low-carbon solutions for your
home. Once you have input details of your home, such as type of
house/flat, amount of insulation in roof/walls and whether or not you
have double glazing, the system identifies a tailored list of optimal
insulation, heating, and renewable energy options (and the costs of each).
The system is particularly useful in allowing you to identify different
options depending on your refurbishment goal, for example whether you
want to make the biggest overall CO2 saving, generate the fastest
payback on your expenditure or make the largest bill saving. In addition,
you can input your budget limit to further refine the options provided.
See: www.tzero.org.uk
3
Sustainable Historic Buildings
Guide for Residents
1.3 Planning considerations
We are keen to encourage residents to take steps to reduce carbon emissions
from their properties and better adapt them to climate change. However,
given the need to conserve the borough’s historic assets, those who live in
conservation areas or listed buildings need to ensure that when installing
measures to reduce carbon emissions or adapt to climate change the special
character and appearance of a building and its wider area is not
compromised. For example, works influencing the external appearance of a
property such as the installation of solar panels need to be considered
carefully with regard to their visibility when viewed from the public realm.
Owners of listed buildings should also ensure that there is minimal
intervention in a historic building’s fabric and that the works are reversible
and do not harm the building’s historic integrity.
Key questions to consider when designing a proposed
external installation
1 Has it been designed sensitively to fit with the appearance of the
existing building?
2 Will it harm to the character or appearance of the building or
conservation area?
3 Will it be visible from the public realm?
4 In the case of a listed building, will the proposed installation harm the
historic fabric of the building and are the works reversible?
Planning permission may be required for works to homes in conservation areas
where such works do not constitute ‘permitted development’. For more
information on renewable energy and permitted development, see the
guidance note ‘Installing renewable energy on your home’ at
http://www.islington.gov.uk/DownloadableDocuments/Environment/Pdf
/installing_renewable_energy.pdf As noted above, works to listed buildings
will generally require Listed Building Consent in addition to planning permission.
For further guidance on the permissions required in a specific case please
contact the Duty Planning Officer (see contact details at the end of this guide).
It is important to be aware, however, that there are many measures to
improve energy efficiency (and reduce energy bills) and adapt buildings to
climate change which will have little or no impact on historic buildings and
will generally not require listed building consent or planning permission. These
include installing upgraded boilers and/or modern heating controls, repair or
restoration of historic shutters, draught proofing of existing windows and
doors and use of low energy lighting. Further details of these measures are
provided in the following chapters.
4
Sustainable Historic Buildings
Guide for Residents
2.0 How to improve energy efficiency
Energy efficiency is the most cost effective approach to reducing energy
use and carbon dioxide emissions and should therefore be considered
before renewable energy generation. There are a variety of free and low to
medium cost measures to improve energy efficiency which are unlikely to
require planning permission or listed building consent. These simple measures
are described below, alongside details on larger energy efficiency
refurbishment projects.
2.1 No cost measures – simple behavioural changes
• Draw curtains/blinds in the evening to conserve heat.
• Check your central heating temperature – 18 to 21ºC should be
sufficient. Turning down your room thermostat by only 1ºC can save
10% on heating bills.
• Check your hot water temperature (usually there is a dial on the hot water
tank) - the recommended temperature is 55-60ºC.
• Avoid leaving electrical equipment such as TVs, computers or stereos on
standby - switch them off at the mains.
• Use low temperature or economy washes on your washing machine, and
wash full loads rather than half loads.
• Defrost fridges and freezers regularly.
2.2 Low cost measures
• Use energy efficient light bulbs - they can last over 10 times longer
than standard bulbs.
• Check you have a well-fitting hot water tank jacket and consider
insulating hot water pipes - a British Standard hot water tank “jacket”
will cut heat loss by up to 75%, cost around £12 and save more than
that in the first year alone.
• Install draught proofing around doors, windows and letterboxes –
a very simple, cheap measure that could reduce your heating bills by
up to £25 a year.
• Invest in thermal lined curtains to reduce heat loss through
windows at night.
• Repair/restore historic shutters.
5
Sustainable Historic Buildings
Guide for Residents
Draught proofing pays back
By installing draught proofing around doors and windows you could save
around £25 a year on your heating bills and reduce your emissions by around
130kg of CO2 each year.
Source: www.energysavingtrust.org.uk/Home-improvements/Home-insulation-glazing/Draught-proofing
Picture credit: Sash Repairs Limited, :www.sashrepairs.co.uk/
2.3 Medium cost measures
Installing insulation in existing roof voids is in many cases achievable and can
help significantly in improving a building’s energy performance. Where a
building has a historic timber roof structure insulation can be introduced
between rafters, without any visual impact or harm to the historic building.
Natural wool or rock wool insulation can be introduced into roofs and can
help to minimise heat loss as well as mitigate acoustic problems.
Insulating floors is another medium cost option. Timber floors can be
insulated by lifting the floorboards (although some boards may be difficult to
lift) and laying mineral wool insulation supported by netting between the
joists. Insulating floors in this way will cost around £100 if you do it yourself,
and could save you around £50 a year. Gaps and draughts around skirting
boards and floors are simple to fix yourself with a tube of sealant bought
from most DIY stores (about £20) and could save around £15 per year on
heating bills. A note of warning, however - don't block under-floor airbricks
in your outside walls. Floorboards will rot without adequate ventilation.
Picture credit: Second Nature, www.secondnatureuk.com/
6
Sustainable Historic Buildings
Guide for Residents
2.4 Larger energy efficiency projects
After considering the above actions and measures you may also want to look
at options for larger projects. These are more likely to require planning
permission or listed building consent so they are dealt with in more depth
below. Opportunities for larger projects to improve energy efficiency include
installing more energy efficient windows, installing improved insulation and
upgrading the efficiency of your boiler.
2.4.1 Energy efficient windows (double or secondary glazing)
There are a number of ways the energy efficiency of windows can be
improved; however, in conservation areas and listed buildings, these must
take into account the impact of any improvements on the historic value of
the building or area.
The appearance of historic windows is important to their context, be it in a
listed building or a conservation area. Many historic buildings in Islington
retain original or historic single glazed sash windows which are characterised
by slim profiles and glazing bars. Listed 20th Century buildings often have
single glazed metal frames which also have characteristically thin and elegant
profiles. As a result of their conservation value, replacement of original
historic single glazed windows is unlikely to be permitted in listed buildings
and will be restricted in conservation areas. Further details of restrictions on
replacing windows are provided in the box below. However there are a range
of measures which can improve the energy efficiency of windows, both
where they can be replaced and where they are being retained.
Where windows cannot be replaced, or budget constraints prohibit
instalment of new windows, there are a range of simpler measures which can
improve the energy efficiency of windows. These include:
• Secondary glazing - adding a second sheet of glass or plastic to a window
frame can improve sound-proofing as well as energy efficiency. If carefully
designed it can be unobtrusive and appropriate in a conservation area
property or listed building.
• Draught proofing - much of the heat lost through windows is actually
through leaks.
• Secondary protection - e.g. shutters or heavy curtains, although these are
predominantly a night-time option.
• General repair and maintenance – this can substantially improve the energy
efficiency of windows (see information box below). These measures also
provide cost effective options for conservation areas.
7
Sustainable Historic Buildings
Guide for Residents
When might replacement of existing windows with double glazing
be appropriate in listed buildings and conservation areas?
In listed buildings, replacing an original historic single glazed window with
double glazed units would have a significant negative impact on the
building’s historic value and is unlikely to be acceptable.
In non-listed buildings in conservation areas the use of conventional
double glazing is more likely to be acceptable at the rear of properties
where there would be no impact on the street scene. In elevations of nonlisted buildings in conservation areas that are visible from the street use of
double glazing may be appropriate if it can be designed to match the look
of existing glazing, but the detailing would need to be agreed with the
Planning and Conservation Department to ensure it does not undermine
the character of the property and conservation area. Use of secondary
glazing may also be beneficial and more affordable.
In new or existing extensions to historic buildings it can in some cases be
acceptable to introduce double glazing, but the detailing would need to be
agreed with the Planning and Conservation Department to ensure it does
not undermine the special character of the property.
Where double glazing is desired, but it is not possible to replace the existing
windows in their entirety, it may be possible to install double glazing in the
existing window frame; this approach would need to be agreed with the
council’s conservation department. For example, it is now possible to insert a
second layer of glazing into some historic sash windows and metal windows,
an approach that can be very effective in saving energy (and that is getting
cheaper as it is more widely adopted). Alternatively, it may be possible to
remove the glazing in an existing single glazed window and replace it with
slim profile, lightweight double glazing, again while retaining the original
window frames. However, unless you have problems with heavy
condensation on single glazed windows, it will be cheaper and easier to
investigate other simpler options for improving the efficiency of existing
windows first (e.g. using heavy curtains and/or secondary glazing).
8
Sustainable Historic Buildings
Guide for Residents
Improving the energy efficiency of sash windows
English Heritage recently completed a study into the thermal performance of
sash windows. The results indicate that even the simplest repairs and basic
improvements will significantly reduce draughts and heat loss, and that using
a combination of these methods will upgrade a window to meet the targets
in the building regulations.
The key findings are:
• Simple repairs to mend cracks and eliminate gaps can significantly reduce
the amount of air infiltration or draughts. On the window that was tested,
air infiltration was reduced by one third.
• Air infiltration through a sash window in good condition can be reduced by
as much as 86% by adding draught proofing.
• Heat loss through contact with the glass and frames can be significantly
reduced by adopting simple measures like closing thick curtains and plain
roller blinds. In the test, heat loss was reduced by 41% and 38% respectively.
Where double glazing is permitted, it’s installation can significantly improve
the energy efficiency of windows. However, the use of uPVC windows is not
considered to be acceptable in conservation areas and listed buildings as this
material detracts from the character and appearance and undermines the
architectural qualities of historic buildings. More sustainable and attractive
materials are available (see box below).
Drawbacks of using PVC windows and alternatives
• PVC (Polyvinyl chloride) is a non-biodegradable material that is made
from non-renewable petroleum resources.
• The production and disposal (via landfill or incineration) of PVC windows
leads to the release of harmful industrial pollutants (e.g. dioxins).
• PVC windows are very difficult to repair, unlike timber frames.
• Contrary to popular belief, PVC windows degrade over time and like timber
windows require maintenance if they are to remain in good condition.
• Based on an analysis of the environmental impact of using different
materials for window frames, Greenspec recommend avoiding PVC and
using instead Forestry Stewardship Council (FSC) durable temperate
hardwood, followed by, in declining order of preference, FSC temperate
softwood clad with aluminium (preferably recycled), FSC temperate
softwood treated with plant based paint, or certified softwood painted
with low VOC paint.
Sources: www.greenpeace.org.uk/files/pdfs/migrated/MultimediaFiles/Live/FullReport/5588.pdf
www.greenspec.co.uk/html/materials/windowframes.html
9
Sustainable Historic Buildings
Guide for Residents
2.4.2 Insulation of walls
Around 35% of a home's heat is lost through the walls, therefore insulation
of walls is another important option to consider. Historic buildings will have
solid walls, rather than the cavity walls which have been built in newer
homes. The only way to insulate solid walls is to add insulation to the inside
or outside of the wall. External insulation involves adding a decorative
weather-proof insulating treatment to the outside of your wall while internal
insulation involves attaching insulating plaster board laminates or wooden
battens in-filled with insulation to the inside of the wall. Both forms of wall
insulation can result in savings of between £300 and £400 per year on
energy bills according to the Energy Saving Trust.
External wall insulation is considerably more expensive than internal
insulation (e.g. at £3500-£5500 for a typical semi-detached house
compared to around £650 for internal insulation). The impact of external
wall insulation on the historic character of the property will also be an
important consideration; use of external insulation is likely to require planning
permission. In conservation areas, external insulation is more likely to be
acceptable where there is already a rendered surface or at the rear of
properties where there would be less impact on the streetscene.
Be warned that in most listed buildings insulation of even internal walls is
likely to be inappropriate as the internal or external build up of walls will
fundamentally change the relationship between the building envelope and its
openings; most significantly it will alter the depth of window reveals and
door reveals, may be too intrusive on the historic fabric and may impact on
the building’s breathability.
Installation of solid wall insulation may be funded through the Climate
Change Fund if you are applying for assistance with renewable energy
systems. Contact the Green Living Centre for details.
1
Source: http://oxfordsolar.energyprojects.net/links/tech_solidwall.htm
10
Sustainable Historic Buildings
Guide for Residents
Case study 1:
429-431 Holloway Road, Islington
The proposed conversion of this building from a reception centre into
14 affordable dwellings raised significant challenges as the new
dwellings needed to meet the latest energy standards while respecting
the character and appearance of the historic building. Moreover, given
the development was 100% social housing the budget was constrained.
Key measures adopted include:
• High levels of thermal insulation and air-tightness and internal
insulation at front, leading to a 59.5% reduction in carbon emissions
compared to the existing building
• Use of secondary glazing with the retention of existing single glazed
timber sashes at the front and replacement double glazed timber
sashes to match original detailing at the rear
• Solar thermal panels give 14.5% on-site C02 reduction
• All hard surfaces are permeable paving, with landscaping designed
for biodiversity
• Water efficiency measures include low flow taps and rainwater
harvesting for irrigation
• Aiming to achieve BREEAM ‘Excellent’ standard
11
Sustainable Historic Buildings
Guide for Residents
2.4.3 Upgrade the energy efficiency of your boiler
Gas boilers generate approximately 60% of the carbon dioxide emissions of a
gas heated home. While a new, high efficiency boiler can cost around £700,
replacing an old, less efficient boiler with a new one could save around £200
per year on your fuel bills and substantially reduce your home’s carbon
dioxide emissions. If you have an old, inefficient G-rated boiler you may be
eligible for a £400 cashback voucher towards the cost of upgrading to an
A-rated boiler from the Government’s boiler scrappage scheme
(see www.energysavingtrust.org.uk/Home-improvements-andproducts/Heating-and-hot-water/Boiler-Scrappage-Scheme).
When considering the installation of a gas boiler, the location of the flue and
the extent to which it will protrude out of the wall need to be considered as
this could impact on the character and appearance of the property. If you are
considering installing a gas boiler and associated flue in a conservation area or
listed building, this should be discussed with the Conservation Department.
On listed buildings and properties within conservation areas, flues on front
elevations are likely to be resisted due to the negative impacts of such
features on the character and appearance of historic buildings.
Case study 2:
Renovated Victorian Eco-home, Camden
This project is an example of heritage and energy conservation aims being
jointly achieved. A private semi-detached Victorian house in a conservation
area was transformed in 2007, reducing its carbon footprint by 60%. Works
undertaken to improve energy efficiency included improved internal wall
insulation, a new fully insulated roof, underfloor insulation, double glazing
and draught proofing. Heat is provided by an efficient condensing boiler
complemented by solar hot water panels on the rear extension; power to the
panel’s water pumps is provided by solar PV panels. Other improvements
include an upgraded ventilation system with heat recovery, water saving
features (e.g. rainwater harvesting for garden irrigation, dual flush toilets),
low energy lighting and energy monitoring.
For further information see: www.sdcommission.org.uk/communitiessummit/show_case_study.php/00230.html
Image source: Sarah Harrison, www.eco-refurbishment.co.uk
12
Sustainable Historic Buildings
Guide for Residents
Case study 3:
Victorian flat eco-refurbishment case study
70a Aubert Park is a Victorian ground floor terraced flat. The refurbishment
of this property focused on internal works that would not detract from the
character and appearance of the property. United House, a housing
construction company, took an experimental approach to the project,
seeking to identify those measures that could be employed to maximise the
carbon benefit for every pound spent. After completing extensive survey
and analysis work, 24 measures were selected for installation; each was
assessed for its installed cost and for its carbon saving effectiveness.
The best six measures were found to be, in declining order of carbon benefit
for pounds spent:
1 installation of low energy lighting throughout
2 draught proofing of windows and cracks/gaps
3 draught proofing of chimney
4 internal wall insulation on external wall of the hall (a note of warning adding new insulation needs to be planned and implemented carefully to
avoid causing condensation and moisture build up in the structure)
5 incorporation of a high efficiency microCHP boiler
6 internal wall insulation on the external wall of the WC.
These measures gave a 50% carbon saving and cost £7000.
Additional measures, principally wall insulation and glazing of sash windows
using new thin-profile light weight double glazing, brought the total cost to
£9000 and the carbon saving to 60%. The study also calculated that if an E
rated fridge and washing machine are replaced by A rated appliances, it
would save a further 5% carbon at low cost.
Image source: Toby Balson, BRE
13
Sustainable Historic Buildings
Guide for Residents
3.0 Renewable energy generation
3.1 Solar PV and solar hot water
Solar technologies, in particular solar hot water panels, offer a cost effective
form of renewable technology for many households (allowing you to save
the cost of the system in an estimated 6-16 years) that can contribute
significantly to reduced CO2 emissions. Moreover, with the introduction of
the renewables feed-in tariff in April 2010 installing electricity-generating
renewable technologies such as solar PV (photovoltaic) may offer an
opportunity to generate a new source of income through selling excess
electricity to the national grid.
Many historic properties will be able to accommodate solar PV panels and
solar hot water panels on the roof but in most cases it will be desirable to
install these out of sight from the street in order to protect the setting,
character and visual appearance of the building and/or conservation area.
For example, on many terraced houses with flat or butterfly roofs solar
panels can be hidden behind parapets; and on buildings with sloping roofs
solar equipment can be accommodated on the rear roof slope (or possibly on
the front roof slope if the equipment would not be visible from the street
due to the height of the building and/or a parapet). In the case of listed
buildings it would also be desirable to make solar panels invisible from
surrounding gardens as far as possible.
However, the orientation of the roof is critical to the operation of the panels for maximum efficiency solar PV and solar hot water panels should be oriented
as close to south-facing as possible. Shading of the panels by trees, buildings or
other structures should be minimised. Where, due to orientation, there is no
option but to use a visible roof for solar equipment, it would be advisable to
consider alternative measures. Each case might have a different suitable solution
and in this situation you would be advised to contact the Conservation and
Design Team for advice (see contact details at end of document). Possible
solutions could include the use of solar tiles instead of a PV panel to reduce the
visual impact of the technology (see box below), although this will be more
expensive, or the use of another type of renewable technology altogether.
14
Sustainable Historic Buildings
Guide for Residents
Solar tiles – solar power with lower visual impact
Solar tiles work in the same way as solar panels but they are the same size
as roof tiles and can be fitted into a tiled roof amongst conventional roofing
tiles. Consequently their visual impact is much reduced. In addition, it is now
possible to buy tiles that are designed to look almost identical to normal slate
roofing tiles, further reducing their visual impact.
Source: www.architectsjournal.co.uk/Pictures/web/n/o/p/Heritage_solar_slates_Maslows_farm.jpg
Case study 4:
Highbury Place and Hamilton Park West
Two properties located in Highbury Fields Conservation Area applied for
permission to install solar hot water and photovoltaic panels.
The owner of a listed building at Highbury Place (see image top left) sought
consent for installing panels on the roof of the rear single storey extension.
Since the planning officer determined that the panels would not be visible from
the street because a parapet blocked any views of the roof, planning permission
was granted. Listed building consent was also granted.
Planning permission was also sought to install panels on the rear roof of a
modern house located within a small modern housing estate at Hamilton Park
West (see two images to left). While it was considered that the panels would be
visible from a footpath and from other nearby houses, given the modern design
of the property and estate and the fact that the panels were to be mounted
flat against the roof slope, the proposal was considered acceptable and
permission was granted.
15
Sustainable Historic Buildings
Guide for Residents
3.2 Ground source heat pumps
Ground source heat pumps use pipes running under the ground to extract
heat for use in a building. The pipes can run vertically into the ground in a
borehole or, if there is sufficient space available, they can be run horizontally
at a shallower depth underground. The practicality of this technology will
therefore depend largely on the outside space available and ground
conditions. The impact of installation on any trees in the vicinity should also be
taken into account and avoided or minimised where possible. The impact on
listed buildings should in most cases be minimal but the impact of ducts and
associated infrastructure on the character and appearance of a building and its
fabric should be discussed with the Conservation Department if in doubt.
3.3 Wind turbines
Wind turbines generally tend to be inappropriate in urban settings because of
a lack of reliable winds at sufficiently high speeds. From a conservation
perspective they will most likely be appropriate only on larger historic
buildings where they can be accommodated at a point on the roof where
they are out of sight from the ground. On modern buildings wind turbines of
modern design may be considered in keeping with the design and appearance
of the building, hence in such instances visible wind turbines may be a
possibility. At present you will need to apply for planning permission to add a
domestic wind turbine to your house, or grounds surrounding your home.
However, new legislation is proposed which may remove the need for
seeking planning permission in certain circumstances.
16
Sustainable Historic Buildings
Guide for Residents
Case study 5:
Ellington Street
The original proposal for this property was for installation of solar hot water
panels and solar photovoltaic (PV) panels on the rear roof slope of this
Grade 2 listed property; hence both planning permission and listed building
consent were sought.
During the course of the application the scheme was revised to remove the
hot water panels and only include the PV panels due to concerns about the
visual impact of the proposal on the listed building and conservation area
(the rear roof slope was visible from the street). Following these changes it
was considered that the installation of the PV panels on the lower section of
the roof slope would be acceptable in principle provided the panels did not
over-dominate the rear roof slope. However, it was considered that the
revised panels height, number and positioning needed fine tuning to ensure
that the character and appearance of the area was preserved. Consequently
the application was approved subject to the planning condition that further
details of the exact number of panels, location and height above the
dwelling’s parapet be submitted.
17
Sustainable Historic Buildings
Guide for Residents
4.0 Climate change adaptation measures
The Intergovernmental Panel on Climate Change (IPCC) defines
adaptation as “adjustments in natural or human systems in response to
actual or expected climatic stimuli or their effects, which moderate
harm or exploit beneficial opportunities”.
Whilst climate change mitigation measures are aimed at reducing the
negative impact of human activity on the climate (e.g. by reducing
carbon emissions), adaptation is about responding to the unavoidable
changes in climate that are already occurring. Adaptation recognises both
risks and opportunities arising from climate change and the need to plan
for them now.
The UK Climate Change Impacts Programme (UKCIP) have compiled a
number of scenarios about the affect of climate change on the UK climate.
The latest probable climate projections indicate that:
• Summers will become warmer and drier, with increased drought risk - it is
projected that by 2050 summers will be at least 3.5ºC warmer than they
are today. In dense urban areas such as Islington temperatures could
increase by as much as 9ºC on the hottest days.
• Winters are likely to become warmer (by around 2.1ºC to 3.5 ºC) and
significantly wetter.
• Torrential downpours will characterise rainfall, rather than a consistent
stream of precipitation needed for water supplies.
• The weather will become more unpredictable with extreme weather events
such as gales, sudden snowfall and heatwaves becoming increasingly
severe and frequent.
18
Sustainable Historic Buildings
Guide for Residents
4.1 Green roofs
Green roofs are intentionally vegetated roofs. A range of types exist from
simple lightweight sedum roofs to biodiversity-based substrate roofs. Green
roofs provide a range of benefits for biodiversity and reducing flood risk
(green roofs can attenuate up to 60% of runoff), providing sound and heat
insulation to a building and reducing the urban heat island effect (the
tendency for air temperatures in urban areas to rise higher than those in
surrounding rural areas). Roofs with deeper substrates are preferred because
they deliver more of the above benefits, which are particularly important in a
dense urban borough such as Islington.
Islington green roofs.
Source: Bere:architects
Green roofs can be retrofitted to existing buildings. They generally require a
flat or gently pitched roof so the number of historic properties to which they
are applicable may be limited (most Victorian properties have pitched roofs).
The types of green roof that could be used on a specific building will be
influenced by the roof loading that it is able to support. As green roofs are
usually installed on flat roofs, their visibility from the street/surrounding area
is often not a concern. In an agreed appropriate setting they may be
considered to have a beneficial visual impact.
With respect to listed buildings, there is also the need to ensure that the
installation of the green roof will not involve loss of historic fabric and
historic roof form; however, there is likely to be greater flexibility where the
proposed green roof is on a modern extension rather than on the original
listed building. Incorporating green roofs onto extensions or new
developments in conservation areas would normally be encouraged.
Further info on green roofs is provided in Good Practice Guide 1 - see
www.islington.gov.uk/greenplanningguidance
19
Sustainable Historic Buildings
Guide for Residents
4.2 Rainwater harvesting
Use of simple rainwater harvesting methods such as water butts connected
to gutters can help to reduce mains water consumption and also reduce
storm water runoff entering the drainage system, reducing flood risk. Where
large areas of roof space make the capture of larger amounts of runoff
water possible, use of stored water for internal uses such as flushing toilets
could also be considered.
There are unlikely to be any concerns from a conservation perspective
related to use of water butts. The impact on listed buildings should in most
cases be minimal but the impact of piping and associated infrastructure on
the character and appearance of a building should be discussed with the
Conservation Department if in doubt.
Source: Bob Bray, Robert Bray Associates Ltd
20
Sustainable Historic Buildings
Guide for Residents
4.3 Soft landscaping and permeable paving
Green spaces and planting, including trees for shading and green roofs and
walls, can dramatically reduce summer time air temperatures by providing
shading and evaporative cooling. This contributes to a more comfortable
living environment, especially as summer temperatures increase with climate
change. Such measures will also help to reduce rainwater run off, reducing
pressure on the drainage system during storm events, support and enhance
biodiversity and improve the environment for people. Conservation area
design guidelines support increases in green space around homes and would
normally resist the loss of soft landscaping in front gardens.
Surfaces that are impermeable to rainwater can be modified to reduce storm
water runoff and therefore flood risk, as well as cleaning and using rainwater
to create attractive landscapes, to irrigate plants or sustain ponds. Hard
surfacing can be replaced with soft landscaping so that water can soak into
the ground. Increasing soft landscaping also provides biodiversity, amenity
and possibly also local cooling benefits. Where hard surfacing is necessary,
this can be designed to be permeable, for example through use of gravel or
other permeable materials, or to shed water into neighbouring soft
landscaping features such as ‘rain gardens’, ponds or wetlands. These
features can also be designed to channel rainwater from roofs to further
reduce storm water runoff and create more extensive landscape features.
Use of landscape features for storing water runoff will require consideration
of the impact on any trees in the vicinity and on any landscape features of
historic importance.
For more ideas on designing gardens which promote biodiversity and reduce
flood risk see the Royal Horticultural Society guide on front gardens
www.rhs.org.uk/RHSWebsite/files/88/8855ec1d-444b-4caf-97a6801ce421b460.pdf
Case study 6:
Islington Town Hall
'Permeable paving' has been introduced as part of improvements to the
forecourt of Islington Town Hall to transform the car park and pavement into a
new attractive high quality public space. Rainwater falling on the new parking
area filters through the permeable paving and is stored in an underground
chamber, before being slowly released to the drains. This process both cleans
the water (helping to prevent pollutants being transferred downstream) and
slows the runoff rate, particularly during heavy rainfall, which helps to reduce
the amount of storm water entering the drainage system.
21
Sustainable Historic Buildings
Guide for Residents
5.0 Further information
If you would like to check whether planning permission and/or listed building
consent would be required for the measures you are considering, please
speak to the Duty Planning Officer between 9 am and 5 pm, Monday to
Friday on 020 7527 2813.
The Conservation and Design Team will be happy to provide further
information and discussion about the suitability of particular measures and
approaches to conservation areas and/or listed buildings. Please call the
above number and ask to be transferred to the conservation officer available
that day. Alternatively, you may send an email to [email protected]
to the attention of the conservation officer.
For further information on energy efficiency see:
• Islington’s Green Living Centre - 020 7527 4462
www.islington.gov.uk/environment/sustainability/sus_visit/GLC.asp
• T-Zero - online tool for comparing options for green home
improvements - www.tzero.org.uk/Homepage.aspx
• Energy Saving Trust - www.energysavingtrust.org.uk/
• English Heritage have guides on energy efficiency in historic buildings
on their website www.english-heritage.org.uk including:
– Energy Conservation in Traditional Buildings
– Climate Change and the Historic Environment
– Cutting Down on Carbon - Improving the Energy Efficiency of
Historic Buildings
• The Victorian Society has information on their website on greening
Victorian homes - www.victoriansociety.org.uk/advice/greening/
• www.buildingconservation.com – provides a directory of useful
contacts, grant sources and websites – www.buildingconservation.com
• Institute of Historic Building Conservation (IHBC) - www.ihbc.org.uk/
22
Sustainable Historic Buildings
Guide for Residents
For further information on renewables see:
• Islington’s Green Living Centre - 020 7527 4462
www.islington.gov.uk/environment/sustainability/sus_visit/GLC.asp
• Climate Change Fund - supports, funds and enables green energy and
transport projects.
www.islington.gov.uk/environment/sustainability/sus_climate/fund.asp
• Energy Saving Trust - Advice Centre for London (co-delivered by
Islington): 0800 512012.
http://www.energysavingtrust.org.uk/Energy-Saving-Trustadvice-centre-London
• www.buildingconservation.com – provides a directory of useful
contacts, grant sources and websites –
www.buildingconservation.com
• English Heritage have a range of guides on renewables and historic
buildings on their website www.english-heritage.org.uk including:
– Wind Energy and the Historic Environment, 2005
– Biomass Energy and the Historic Environment, 2007
– Micro wind generation and traditional building, 2007
– Small-scale solar thermal energy and traditional buildings, 2008
– Small scale solar electric (photovoltaics) energy and traditional
buildings, 2008
– Microgeneration and the historic environment, 2008
23
Sustainable Historic Buildings
Guide for Residents
For further information on climate change
adaptation measures see:
• Islington’s good practice guides on climate change and biodiversity www.islington/gov/uk/greenplanning/guidance
• Sustainable Drainage Systems – a guide for developers: Environment
Agency - www.environmentagency.gov.uk/business/sectors/39909.aspx
• A range of SUDS publications are also available from the CIRIA
website including Sustainable Water Management in Schools and
The SUDS Manual - www.ciria.com/suds/publications.htm
• English Heritage - Climate Change and the Historic Environment http://www.englishheritage.org.uk/upload/pdf/Climate_Change_and_the_Historic_
Environment_2008.pdf
24
www.islington.gov.uk
Reducing carbon emissions and adapting
to climate change in historic buildings
While there may be occasions when climate change objectives conflict
with the conservation of heritage assets, many opportunities exist for
taking action to tackle climate change without negatively impacting on
conservation value. This guidance note outlines a range of approaches
for increasing energy efficiency (and reducing heating bills), generating
renewable energy and adapting to climate change that may be suitable
for listed buildings and homes in conservation areas. It includes free,
low and medium cost measures as well as ideas for larger
refurbishment projects.
Image: Rear elevation of listed building at Ellington Street with solar panels on roof.
If you would like this document in large print or Braille, audiotape or in another
language, please contact 020 7527 2000.
Contact Islington
222 Upper Street, London N1 1XR
E [email protected]
T 020 7527 2000
F 020 7527 5001
Minicom 020 7527 1900
W www.islington.gov.uk