Structural Glass for Historic Churches
||A new glass balustrade at St Peter’s Church, Dunchurch, Warwickshire
(All photos: Ion Glass)
Many of Britain’s most inspiring
churches are centuries old and
while much of their charm lies
in their historic architecture and materials,
it’s important that the needs of modern
congregations aren’t overlooked in favour of
zealously preserving them in the time-warp
of a previous century. Too many historic
churches have become redundant shells in
recent decades, and sympathetic adaptation is
often key to their survival, enabling wider use
by the community and the congregation itself.
Common problems include open draughty
spaces that are impossible to heat; a lack of
contained spaces to hold private meetings; fire
protection and security issues around entrance
doors; the need to introduce an acoustic barrier;
or insufficient space for a thriving congregation.
While ongoing maintenance and
conservation of the existing building are
obviously important, the problem of how to
update the church to meet 21st-century needs
and standards without losing the magnificence
of the existing architecture can prove a bigger
Provided it is correctly installed, structural
glass is robust, durable and easy to maintain
and will meet a wide scope of contemporary
requirements with minimal aesthetic impact.
Creating new spaces with glass will still permit
natural light to illuminate the interior (especially
important where stained glass windows are
a prominent feature) while retaining heat
and sound. Use of architectural glass opens
up exciting opportunities to make significant
changes to the functionality of the space without
obscuring or damaging historic church fabric.
Measuring the space is of particular importance when working in historic buildings because
the stonework was hewn by hand. Arches
that appear to be perfectly regular often
prove to be substantially asymmetrical when
surveyed using a laser distance measurer.
Fitting glass perfectly around stone corbels
and carvings requires additional precise
detailing and the use of a contour gauge
(a comb-like device with sliding metal teeth)
will record every nuance of the stonework
to achieve the optimum result. Each panel
of glass must be manufactured to order and
accuracy in specification is critical. Glass
industry standard tolerance in manufacture
varies depending on the size of the panel but
a close fit to the original stonework can be
achieved by a glass specialist with experience
in recording intricate and irregular surfaces.
CREATING SPACES WITH GLASS
Whether it’s a place where younger children can
be cared for during Sunday services to allow
their parents to worship without distraction,
or a private area for discussion or counselling,
the addition of a meeting room in a church
creates the potential for new and extended uses.
Holy Trinity Church is just off Sloane
Square in the heart of fashionable Chelsea.
Its tight urban site meant that the church’s
requirement for meeting rooms had to be met
within the church – there was no opportunity to
expand externally. Built in the late 1800s, Holy
Trinity has been described as ‘the cathedral
of the Arts and Crafts Movement’ and it
contains treasures by some of the leaders of the
movement, including magnificent stained glass
by Edward Burne-Jones and Christopher Whall.
|Above left: Precision detailing at St Clement’s Church, Hastings and, above right, the use of highly accurate measurement and cutting
tools allows a close fit where structural glass elements
need to follow the contours of the original fabric.
An area under the original gallery on either
side of the main entrance to the church had
been used for informal meetings and storage
but offered no privacy. Plans were drawn up to
create two rooms constructed from structural glass which would allow an unhindered view
of the nave.
To reduce noise transmission, the
screens were fixed into channels in the floor
and the ceiling above and stepped back from
the columns, creating a continuous wall of
glass without any gaps. The use of acoustic
glass, which is laminated with an acoustic
interlayer, further reduced both transmitted
and reflected sound, contributing to a quiet
and private environment.
Due to the height
of the screen it was necessary to fit stabilising
fins on the panels (facing page, top right)
which were also manufactured from glass,
ensuring there was nothing to interfere with
the minimal appearance of the structure.
Moving an original metal screen
from the rear of the church to the front
of the new meeting rooms retained the
style of the Arts and Crafts movement,
combined with a motif applied to the glass
that replicated the one on the screen.
MINIMISING HEAT LOSS
Heating the church of St Nicolas at
Great Bookham had become a significant
drain on resources. The church, which dates
back to the 11th century, is an archetypical
village church that had evolved over the
centuries but had not seen any significant
improvements for many years.
The combination of heat loss up the ancient
(and little used) west tower and draughts from
the wooden doors meant that the congregation
had become used to feeling the chill in winter.
Ion Glass was engaged to install
a screen across the width of the nave,
combined with a glass door to sit inside
the existing wooden entrance door.
Keeping the visual impact of the screen to
the absolute minimum involved a technically
difficult construction using vertical glass fins
to stabilise the multi-panel construction of the
arch. The decision was taken to fix the panels
of glass to the ancient stonework by using a
series of stainless steel clamps in preference
to a continuous metal channel. This approach
minimised the impact on the ancient fabric
of the walls and was less intrusive visually.
The glass door which is set into the screen
is over a metre wide, allowing easy access
for wheelchair users and for pall-bearers
during funeral services. An impressive three
metres in height, the door had to be fixed
into an over-sized floor spring cut into the
original stone floor, and bespoke fixings
were manufactured to take the weight and
provide lateral stability while at the same
time offering minimal visual impact.
Use of a laser distance measurer and
contour gauge ensured that the screen fits
closely around the exact shape of every corbel
and is sealed to minimise heat loss. The screen
also minimises the acoustic intrusion of the
bells during services. Because the external door
in the west tower is now in regular use as the
main access to the church, parishioners can also
enjoy the full glory of the aisle, stained glass
windows and altar as they enter the building.
|Above left: a curved balustrade St Andrew Undershaft in the City of London. Above right: Holy Trinity, Sloane Square, London: structural
glass fins provide stability to a glass partition.
Incorporating a mezzanine floor or gallery area
can significantly increase floor space while the
addition of a glass balustrade lets light in and
maximises the visibility of original features.
Various glass balustrade systems are
available with a range of options regarding
fixings. Choosing the right system for a
particular church requires careful consideration
of the relevant design aesthetic, construction
and cost constraints. Both curved and straight
glass panels can be incorporated and the
panels can be cut to fit around stonework,
out-of-true walls and arches. It is also
possible to make the balustrade frameless,
avoiding the visual distraction of a handrail.
The balustrade installed recently at
St Andrew Undershaft in the City of London
is constructed from 21.5mm toughened
laminate glass, bolted to the substrate of
the gallery floor using a bespoke system.
A single row of stainless steel bolts across
the front edge of the gallery helps to create a
clean, stylish finish while a white film applied
directly to the glass masks the unfinished
edge of the floor. With curved panels at
either end it provides an elegant sweep of
glass across the whole width of the gallery.
With no visible clamps, posts or handrail,
the installation is deceptively simple but remains
fully compliant with the relevant building
regulations. The design ensures that people using the meeting space on the gallery floor
have an uninterrupted view of the nave while
the natural light provided by the magnificent
stained glass windows is unimpeded.
Hurst College, an independent school in
Sussex has a long-standing tradition of regular
worship, conducted in a glorious chapel built in
the late 1800s. The school has increased in size
and no longer had enough room in the chapel
for the regular whole-school service. The high
Victorian ceilings, however, provided sufficient
space to build an unobtrusive suspended
gallery above the main chapel entrance.
The design included a channel-set
glass balustrade around the gallery with
straight panels and concealed fixings.
The balustrade was finished with a
polished steel handrail, in keeping with
other glass installations in the school.
PROTECTING STAINED GLASS
||A spider fixing at St Andrew Undershaft
Making structural changes to the body of a
church can raise floor levels so that windows
previously high above ground level become
accessible and at risk of damage. One solution
is to install a glass panel in front of the
original window. A sensitive approach to
design and installation is needed to ensure the
surrounding stonework isn’t damaged while
at the same time protecting the window and
meeting current building specifications.
The new gallery floor at St Andrew
Undershaft is reached via a new
staircase that sits directly in front of the
splendid stained glass windows and a
barrier was essential for protection.
A series of individual glass panels was
installed in front of the stone mullions using
purpose-made stainless steel supports and
spider fixings (right) to stand the glass off
the stone and avoid any damage to the carved
surface. The result is a stylish span of glass at
the side of the stairs that highlights and protects
the leaded windows without obscuring their
intrinsic beauty or blocking natural light.
At St Peter’s Church in the village of
Dunchurch, near Rugby a new bell-ringing
platform in the church tower created a
room at the same height as the stained glass
window. An over-sized glass panel was
manufactured to fit in a single span in front
of the window with bespoke stainless steel
fixings to hold the glass in place. The panel
is unobtrusive but protects the window
from users of the bell-ringing platform.
A CLEAR WELCOME
Installing glass doors, preferably in addition
to rather than as a replacement for traditional
wooden doors, provides a secure but welcoming
entrance that meets a range of modern needs.
Glass entrance screens make it easier to install
alarms and security protection, and create
a barrier against noise, traffic fumes and
heat loss while allowing a clear view of the
interior, welcoming people into the church.
Bespoke doors can be customised to
reflect the spirit of the individual church:
at St Peter’s in Dunchurch handles were
manufactured to reflect the exact arch of the
nave; other churches have opted for an applied
glass motif to echo designs incorporated
into the altar cloth or carved screens.
At St Andrew Undershaft where the church
is primarily used as a centre for Bible studies,
a pair of secure glass doors was fitted inside
the existing wooden doors. The doors are set
into a stone archway with fixed glass panels
on either side and an arched glass over-panel,
all of which had to be accurately shaped to the
stone and fixed in place with stainless steel
clamps. Detailed and accurate measurements
were taken to ensure that the glass fits
perfectly against the original stonework.
It is possible to avoid the need for a visually
obtrusive lock in the middle of a glass entrance
door by fitting electromagnetic locks at the
top or bottom. At St Andrew Undershaft a
stainless steel transom houses the upper pivot
point for the pivot doors and acts as a fixing
point for the electromagnetic locks, which
are linked to the church alarm system.
Glass is a versatile material that opens up
many possibilities, allowing historic churches
to meet modern requirements with minimal
impact on the original structure. To ensure
that the completed project meets all design and
installation criteria and is fully compliant with
current regulations, it is important to use an
experienced glass specialist from the outset.