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External lightingfor historic buildings
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CONTENTS
1 Introduction 1 10
10
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12
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2 General considerations
Should the building be lit?
Does the entire building need to be lit?
Is there a pattern or arrangement which should
be featured?
Where can external lights be positioned?
Are there any adjoining properties? Is light spilling
from the surroundings?
How big and how clean is the building?
Are there environmental matters to consider?
What is the most suitable light source?
How are illumination levels established?
Are trials necessary?
2
2
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3 Types of lighting
Conventional external lighting schemes
Architectural lighting
Dynamic lighting
4 Types of light sources and levels to use
Lamp Data
Available lumen intensities and distributions
5 Types of control systems
6 Environment, security and dark skies
Effects on the environment
Security
Dark skies
7 Installation and maintenance issues
8 Glossary
9 Bibliography
Web-based reference material
10 Useful Addresses
11 Acknowledgments
The information in this publication is based on our current knowledge.
Whilst every effort has been made to ensure the accuracy of the advice given,
English Heritage does not accept liability for loss or damage arising from the use
of this information.This publication is intended as a general guide and should
not be used as a substitute for professional advice
The inclusion in this publication of any company, group or individual, or any
product or service, should not be regarded as either a recommendation or
an endorsement by English Heritage or its agents.
The installation of an external lighting system implies in most cases the fixing of
equipment to the fabric of a building. English Heritage seeks to ensure that any
works to a historic building do not disturb or destroy historic fabric.
In deciding how best to illuminate a building, the principles of minimum
intervention and reversibility should be adopted whenever and wherever possible.
FRONT COVER: Image showing a lit building situated along Grey Street, Newcastle
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INTRODUCTION
Our historic buildings and monuments are often amazing feats of architecture and engineering.
Many have been enhanced and brought to life at night-time with striking and subtle externallighting schemes. Some, however, have produced far more negative results by highlighting flaws and
views of the structure never meant to be seen. Just because a building or structure happens tobe listed does not mean this is a good enough reason to proceed with external lighting.
1b
There are a number of matters that should be examined
before progressing with a design.The most important of
these is the question, ‘Has a real need to install lighting
been established?’ The next must be the acceptance that
a simply technical approach is useless.
The main objectives of external lighting should be:
● to promote observation and experience of the siteagainst the night sky
● to give the building an added dimension which will
enhance its key architectural elements as well as its
social and historical significance
● to improve the quality of the nocturnal environment
by promoting safety, ie avoidance of trip hazards
● to enhance night-time orientation and use, which
could potentially benefit the local economy
Therefore an aesthetic, as well as a technical, approach
is essential and will ultimately govern the result.
When external lighting is executed with a well-designed
and co-ordinated scheme using the correct choice
of equipment, the environmental impact, ie light
pollution and overspill, can be minimised and the energy
efficiency maximised.
1cSubtle external lighting when designed with care and
sensitivity can bring added life and scope to some of
our most treasured landmarks. It becomes an extension
to the architecture, improving the quality of the viewand complementing the structure’s shape, colouration
and form. It gives an added dynamic by bringing the
‘soul’ back into a place, and can be likened to ‘painting
with light’.
1a
1
1a Kingston upon Thames Bridge. (Photograph courtesy of Sill Lighting)
1b The Poseidon Fountain,Witley Court,Worcestershire.(EH photo library K971385)
1c Concentration of light on a prime local site.
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3b
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GENERAL CONSIDERATIONS
Should the building be lit?
If a real demand for lighting has been established in
conjunction with the owners or custodians, then the
designer must look to limit the amount of light to that
strictly necessary to achieve the aims of the scheme.
Does the entire building need to be lit?
It is rarely necessary to light all the elevations of a
building, some parts often being unsuitable or inaccessible
for viewing. It is usually better to concentrate on the
prime nearby and distant night-time viewpoints. As part
of the design process distance, angle and position of the
viewer should always be taken into account.
Is there a pattern or arrangement which should
be featured?
It is often better to illuminate selected architectural and
sculptural features such as pediments, columns, porticos
or niches, rather than illuminating the whole building.
External lighting to reinforce a building’s patterns can
increase the appreciation of architectural details.
Crosslighting, uplighting and backlighting should all be
considered, although uplighting must be limited and
well controlled to avoid light pollution.
Designs can be refined by the use of tight beam
control; shutters or baffles can also help reduce
night-time light spill. However, the latter solution is
rarely acceptable in appearance during the day unless
the fittings can be concealed.
This leads to the next question.
2ab Night and day views of Government House in Guernsey. Only thearchitecturally important sections of the front elevation have beenilluminated. (Lighting design by Sutton Vane Associates)
3a Backlighting used at Manchester Crematorium. (Photograph courtesy of Lighting Architecture)
3b Uplighting used to illuminate Central Exchange Buildings, Grainger Town,Newcastle upon Tyne. (Lighting design by Sutton Vane Associates)
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5a
5b
5c
Where can external lights be positioned?
It is essential that all luminaires are inconspicuous, easy
to install and maintain, and respectful of the historic
fabric. Even though a lighting design may give the
desired effect at night, if the floodlights cannot be
effectively hidden from view or disguised, the scheme
must be rethought.
One solution is to floodlight from a remote position.
Luminaires can be positioned on nearby buildings or
street furniture. Where there are trees and shrubs it
may be possible to disguise lighting poles.
3
4 Lighting to emphasise the pattern on a building.
5abc Lights hidden from view in basement or lower pavement areas andhow they should be aimed. (Fig 5c courtesy of the Institution of Lighting Engineers)
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Are there any adjoining properties? Is light spilling
from the surroundings?
Neighbouring properties and the surrounding area must
be taken into account. In rural areas, with lower ambient
light levels with which to compete, less light will be
needed to floodlight a building.This is often overlooked in
lighting scheme designs.This will reduce both the initial
outlay costs and ongoing energy consumption.
How big and how clean is the building?
As well as the existing ambient lighting, the reflectivity of
the building surfaces must be taken into account.This will
be affected by the colour of the building materials, and
how clean they are.The more reflective a building, the
fewer luminaires will be needed and the less powerful
they will need to be.
Are there environmental matters to consider?
Lighting can affect some animals (for example bats and
owls) that make historic buildings their home. Some animals
and their habitats are protected by law.Where proposed
external lighting may affect such animals an impact
assessment will need to be made, taking into account
breeding, hibernation and points of egress and ingress. As
well as the increase in light levels, the effects of installation
and maintenance must also be taken into account.
6b
6a Remote light on a pole hidden by foliage.
6bc Remote light disguised by a street lantern. (6b Lighting design by SuttonVane Associates)
7 Wildlife considerations.
6a
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8a
8b
What is the most suitable light source?
The choice of light source must take into account the
colour and reflectivity of the building surfaces, the desired
colour rendering, the colour or operating temperature
of the lamps, and their effect on the building materials.
Street lighting designers have begun to move away fromhigh-pressure sodium (SON) lamps to metal halide (HIT)
lamps, which is to say from warmer, red tones to cooler,
blue tones of the colour spectrum. When choosing
floodlamps the designer must take into account both the
colour and the level of the local street lighting.
To increase impact an interesting effect can usually be
achieved by using a lamp of a type different to that being
used for the existing lighting, and this can also reduce the
necessary number of luminaires and their power rating. If
there is any doubt as to which lamp should be chosen, then a small field trial will usually be enough to determine
the correct type.
How are illumination levels established?
The following publications provide standards and guidance:
● British Standards 1996 Road Lighting. Code of
Practice for Lighting for Urban Centres and Public
Amenity Areas (British Standard BS 5489-9:1996).
With simple examples of the calculation process
● Chartered Institution of Building Services
Engineers (CIBSE) 1992 The Outdoor Environment
(Lighting Guide LG6). London:The Chartered
Institution of Building Services Engineers. Includes
various lighting techniques
● International Commission on Illumination (CIE) 1993
Guide for Floodlighting (Publication 94).Vienna:
International Commission on Illumination
● Electrical Contractors Association (ECA)
Decorative Exterior Lighting of Churches. London:
Electrical Contractors Association. Includes
procedures for defining the most suitable type of
lamp and location based upon the type of building
material and its condition
● Institution of Lighting Engineers (ILE) 1994 Lighting
and Crime. Rugby: Institution of Lighting Engineers
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8a Soft lighting of a rural building.
8b Muncaster Castle, Cumbria. (Lighting design by Sutton VaneAssociates; photograph by Brian Sherwin)
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Are trials necessary?
The technicalities of colour rendering can be difficult to
visualise, so it is often very useful to arrange a site
demonstration of the options being considered.
Photographs taken during the trial can be very useful
when applying for planning permission.
With general historic environment and building stock,
consultation of the government’s Planning Policy Guidance
Notes (PPGs) – Planning Policy Guidance 15 (PPG 1994)
in particular – and their replacements, Planning Policy
Statements (PPSs), should be made.These documents
provide a framework and a useful reference to the overall
principles and requirements of the planning system. In
addition a proposal to externally light a building may need
planning permission under the Town and Country Planning
Act 1990, so early involvement of the local planning
authority is recommended as many aspects of the designhave the potential to be affected.
When the building in question is a church that the parish
wishes to light, it is often worthwhile experimenting to
try and resolve as many problems as possible before
approaching the Diocesan Advisory Committee.The
committee will be concerned with all implications of
the design, including the financial costs (capital, running
and maintenance).
Where any historic property is within the environs of
an airpor t, development restrictions can apply, especially if the building comes within the airport’s public safety zone,
in which case additional early consultation will
be required.
11a10
9 All Saints Church, Newcastle upon Tyne. A lighting scheme employingmetal halide lamps against a background of high-pressure sodiumlighting. (Lighting design by Sutton Vane Associates)
10 Wide wash of light onto a building.
11ab Remote lighting locations using street furniture or other buildings.
11c Light mounted on a lamp-post; compare the cluttered effect here withFig 6b. (Photograph cour tesy of Sutton Vane Associates)
12 Dynamic lighting of The Monument, City of London.
13ab Illumination of selected elements of buildings.
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Dynamic lighting
This choice makes use of theatre-style lighting fixtures
to produce coloured light, moving patterns or
projected images.
Dynamic lighting has limited use, but where the building
is very plain and unadorned it can be pleasing for special occasions and celebrations. I should be stressed,
however, that a permanent dynamic display can quickly
become boring.
It is better to employ dynamic lighting for short periods of
time; good example are the pink floodlighting of London’s
Wellington Arch for Breast Cancer Awareness Month in
2001 (see Fig 15a) and its subsequent illumination with
images of falling poppies for the 80th anniversary of the
Royal British Legion. At Christmas time, the Amiens
Cathedral in France has a 45-minute light show whichcolours the façade as it would have been in medieval
times, painted and gilded, only this time with light.
15b
14
14 Coloured lighting of a building.
15a Wellington Arch, London, for Breast Cancer Awareness Month, 2001.(EH photo library K010791)
15b St Paul’s Cathedral for World Aids Day, 2002. (Lighting design by Sutton Vane Associates)
15a
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TYPES OF LIGHT SOURCES AND LEVELS TO USE
Listed below are the most commonly used light sources for external lighting.
Lamp data
Lamp type Colour appearance Colour Rendering Efficiency Rated life (hours)
Index Ra (sun=100) (lumens/watt)
Tubular fluorescent White 50–90 Good 15–70 Medium 6,000–10,000.
Compact fluorescent White 80 Good 25–80 Medium 10,000
Metal halide, warm White 65–80 Good 50–95 High 6,000–20,000
colour (also used in
fibre-optic systems)
Metal halide, cool White 65–90 Good 50–105 High 6,000–20,000
colour (also used in
fibre-optic systems)
High-pressure mercury White 40–50 Poor 25–55 Medium 12,000–24,000
High-pressure sodium Yellow 25–60 Poor–medium 55–130 High 14,000–24,000
Low-pressure sodium Orange Not applicable 70–180 High 16,000
(monochromatic)
Light-emitting diodes White (also 70 White Good 7–10 Poor 50,000–70,000 (but can
(in array form) blue, amber, (although colour varies at present but be limited by driver life
green and red) between manufacturing improving to 20,000–50,000)
batches)
CDM (ceramic White 80–90 Good 70–95 High 6,000–9,000
discharge metal halide)
Note: tungsten and tungsten halogen lamps have been excluded here: although these have excellent colour
rendering, lamp lives and efficiencies are very poor.
Available lumen intensities and distributions
Type of illumination Peak intensity Light distribution Comments
(lumens)
Symmetrical beam 1000–2000 Beam width Popular due to low initial costs, but little(discharge lamps) real optical control
Symmetrical ‘projector’ 200–30,000 Beam width A useful tool if carefully applied
beam
Simple asymmetric 800–3,000 Beam width Popular due to light weight
beam
Asymmetric beam with 700–800 Beam width Gaining popularity due to good control
horizontal cut-off of upward light
Bulkhead lights 150 Light distribution Very wasteful unless used in confined space
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TYPES OF CONTROL SYSTEMS
The control of an external lighting system does not
necessarily require anything more complicated than a
simple time switch or a photoelectric cell. Many schemes
only operate for a few hours of darkness (for example
until 23.00) to prevent unnecessary energy use. Electricity
bills are kept low, and the lighting causes much lessinterference with flora and fauna. Astronomers also
benefit from the reduced light pollution.
Round-pattern time switches (as they are often known)
come in a variety of ratings and types. Most provide
the user with on–off operation which tracks sunset
and sunrise times throughout the year, without the
need to sense light levels. An added facility allows the user
to select a fixed ‘off ’ time – say between 20.30
and 01.00 – and a fixed ‘on’ time. Switches can be
provided with a reserve battery, so that power outages donot affect operation.
Round-pattern switches give greater control than photo-
sensing devices, which must rely on the level of natural
light to operate, usually coming on at dusk and switching
off at dawn. On dark and cloudy days photoelectric
switches would be activated unnecessarily.
Time clocks can be retro-fitted as surface-mounted units,
or designed to be DIN rail – or panel-mounted to suit
the site.They are provided with openings and seals for
security to prevent possible tampering with the settings.
If more sophisticated operation is required, there are
proprietary control systems available, but these can be
expensive. For most straightforward external lighting
schemes, complex systems are unnecessary.
ENVIRONMENT, SECURITY AND DARK SKIES
This section looks in more detail at some of the issues
mentioned previously. Environment, security and dark skies(light pollution) are all important issues, each of concern
to different interest groups.
Effects on the environment
External lighting can be extremely disturbing to a variety
of plants and animals. Excessive light can have a dramatic
impact on the lives of nocturnal species such as bats, frogs,
lizards and birds by confusing their circadian rhythms
16
16 Line drawings showing types of illumination
17 Useful light, spill light and light trespass. (Diagram courtesy of theInstitution of Lighting Engineers)
17
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(natural patterns of living and breeding). Light can also
affect the feeding habitats of nocturnal hunting birds
(such as owls) and endanger other birds by disturbing
their sleep patterns (a false sunrise which confuses them
into singing).
As well as animals, trees and nocturnal insects are
also affected. Normal seasonal variations may bedisturbed, affecting their interdependency and
associated ecosystems. Any reduction in numbers of
insects such as moths reduces the food supply of higher
birds and animals.
Security
‘More light equals less crime’ is often cited as a reason for
external lighting, but there is little hard evidence to
support this statement. Despite the popularity of external
lighting, crime rates have soared and published Home
Office statistical evidence indicates that the presence or
absence of light is of little or no importance.The fear of
crime can certainly be alleviated with good external
lighting, but poorly positioned or misdirected lights can
dazzle passers-by and create deeply shadowed areas
which hide cr iminal and anti-social activity.
Well-positioned luminaires will do more to deter criminals
than over-lighting. Passive infra-red sensors can give an
element of surprise to deter intruders outside the normal
operating times of the lighting system.
Dark skies
Artificial lighting has enabled us to do much more during
the hours of darkness, but this freedom comes at a price.
‘Light pollution’ is another term for sky glow, the
brightening of the night sky caused by dust and aerosol
particles of water in the air, which scatter any artificial
light.This light comes from wasteful all-night shop
advertising and display illumination, and from poor
external lighting schemes.
Light pollution prevents much of the population from
being able to enjoy the night sky. Sky glow now pollutes
nearly all of Britain’s night skies, interfering with
professional as well as amateur sky-gazers.
Simple spillage from a badly designed external lighting
scheme can cause a major nuisance to others, for example
by trespassing into a window and keeping occupants
awake.This is in addition to the wasted electricity and its
contribution to emissions of greenhouse gases.
However it is not sky-gazers who are responsible for most
of the work that has been carried out to reduce light
pollution. It is, in the main, down to conservationists,
individual residents and local communities.
INSTALLATION ANDMAINTENANCE ISSUES
Care in the installation of external lighting is doubly
important when it is actually fixed to the building. Such an
installation may require listed-building consent.Without
thoughtful consideration, light fittings may not only
disfigure the façade but their installation may also leave
permanent scars on the fabric.
The location of any luminaire should always take into
consideration the material onto which it is going to be
fixed.To avoid unnecessary destruction, fixings should be
drilled into joints rather than into stone and brick.Where
this is not feasible, pattresses should be used.
Maintenance is also important; without it the output and
safety of the final installation will be seriously jeopardized.
However, it is too often viewed as an unnecessary
expenditure and neglected. Neglect will inevitably result in
system failure, and is uneconomic in the long run. Lighting
maintenance should be scheduled into the building’s repair
and upkeep. Regular inspections should be made
(generally every 3–6 months) during which fittings arechecked and cleaned and any faulty luminaires and lamps
replaced. Reactive maintenance should be kept to a
minimum where possible.
Maintenance is less likely to be regular if access is difficult
and expensive. If special equipment or personnel are
needed to reach the light fittings, even replacing lamps or
cleaning will be prohibitive. However, ease of maintenance
may need to be reconciled with the need to hide or
disguise the luminaires.
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Paterson, James and Mackness, Malcolm 2000 ‘How to do itNo 4: Church floodlighting’. Lighting Journal May/June 2000,10–11
Ramsay, Malcolm 1991 The Effect of Better Street Lighting onCrime and Fear: A Review (Crime Prevention Unit paper No
29). London: Home Office Crime Prevention Unit
Web-based reference material
Building Conservationwww.buildingconservation.com
LightPollution.orgwww.lightpollution.org.uk
Church Care (Church of England) www.churchcare.co.uk
USEFUL ADDRESSES
Catholic Bishops’ Conference of England and Wales39 Eccleston SquareLondon SW1V 1BXTel: 020 7630 8220www.catholic-ew.org.uk
The Chartered Institution of Building Services Engineers222 Balham High RoadBalhamLondon SW12 9BS
Tel: 020 8675 5211www.cibse.org
The Church of EnglandNational Church Institutions Administrative CentreChurch HouseGreat Smith Street Westminster London SW1P 3AZTel: 020 7898 1000www.cofe.anglican.org
Electrical Contractors Association
ESCA House34 Palace RoadLondon W2 4HYTel: 020 7221 7344www.eca.co.uk
English Heritage1 Waterhouse Square138–142 HolbornLondon EC1N 2STTel: 020 7973 3000www.english-heritage.org.uk
Institution of Lighting EngineersRegent HouseRegent PlaceRugby CV21 2PNTel: 01788 576492www.ile.org.uk
Natural England(Incorporating English Nature, the Countryside Agency and the Rural Development Service)Northminster HousePeterborough PE1 1UATel: 0845 600 3078www.naturalengland.org.uk
ACKNOWLEDGEMENTS
English Heritage would like to acknowledge the help of thefollowing people in the production of this guide:
Alan Anderson, Lighting Architecture
Robert Bohannon, Sill Lighting UK
David Coatham, Institution of Lighting Engineers
Javis Gurr, English Heritage photo librar y
Steve Newbold, Electrical Contractors Association
Graham Smith, CES
Mark Sutton Vane, Sutton Vane Associates
Text by Geraldine O’Farrell, English Heritage Building servicesEngineering and Safety Team (BEST)
Figures 1c, 4, 5a, 5b, 6a, 7, 8a, 10, 11a, 11b, 12, 13a, 13b, 14and 16 by Judith Dobie, Centre for Archaeology, EnglishHeritage
Edited by John King
Design and Production by Creative Services,English Heritage, 04/07
Printed by Vitesse (1000)
Product code 51330
April 2007
BACK COVER: Hoover Building at night, Perrivale, London 13
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For copies of this leaflet, please contact English Heritage Customer Services
Department on 0870 333 1181 or email [email protected].
Published by English Heritage, April 2007. Product Code 51330. Copies are also
available on www.english-heritage.org.uk and www.helm.org.uk. Printed on
recycled paper containing 75% post-consumer waste.