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Peter Hazeldean, MD of Ion Glass is passionate aboutthe use of
structural glass to meet many differentrequirements, especially
with regard to a variety ofconservation projects. He shares why
glass is such aversatile building material for modernising
churchesand heritage buildings:
“There are so many possibilities with structural glass.It not
only looks stylish but it’s amazingly robust andfunctional. In a
heritage environment glass has asignificant advantage over other
materials in that it canbe installed with minimal impact to the
structure of thebuilding, both physically and visually.
Ion Glass has developed techniques for fixing glass tostonework
without the need for bulky or intrusive
bracketry, using structural glass fins for additionalsupport
where required. We’ve also enhanced standardmeasuring and
templating techniques to ensure theglass itself sits tight to walls
and floors, even if there areintricate stone corbels or
irregularities in the surface.
Installing glass screens or glass doors can greatlyimprove heat
retention as well as creating a morevisually welcoming entrance. We
have undertaken anumber of projects where a glass entrance lobby
withglass doors has created a secure but welcomingentrance that
will keep the heat in and the wind out –often allowing the original
wooden doors to be fixedopen to let more light into the building
and to providevisual access to the interior.
Structural Glass forConservation Projects
Main picture: St Leonard's Church, Hythe; structural glass
entranceInsert: St Nicolas Church, Great Bookham; structural glass
screen and glass doors
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If the requirement is to create more space, structuralglass is
often the only solution for linking a heritagebuilding to a modern
extension. We can install a glasslink with minimal footings and the
resulting structurewill have enough flexibility to cope with the
disparitybetween old and new building methods. EnglishHeritage
often prefer to have a distinct visual breakbetween the original
building and the new addition –and glass is the optimum
choice.”
We asked Peter for any other advice he could offerregarding
installing glass in heritage buildings:“In my view it’s really
important that the installationteam are sensitive to the buildings
they are working in.Ion Glass only uses our own fully employed
techniciansand with many years of experience they appreciate
theparticular nuances of working in heritage buildings. It’salso
important to have an understanding of conserva-tion and heritage
requirements. We are used toensuring our glass installations not
only look fantasticand work flawlessly – but also meet the needs of
EnglishHeritage, the Church Conservation Trust and
otherconservation bodies!”
Interested? Ion Glass share some recent case studiesSt Leonard’s
Church in Hythe commissioned Ion Glassto install a glass screen and
glass doors to create a draught-proof porch.For over 900 years St
Leonard’s Church has stood highabove the market town of Hythe on
the South Coast
of England. The church is renowned not just as a placeof worship
and pilgrimage but, more uniquely , for thebones and skulls housed
in its crypt, an ossuaryestimated to represent the remains of
around 4000people and the largest and best preserved collection
ofits kind in Britain.
The crypt attracts a lot of outside visitors to the churchbut
nevertheless St Leonard’s is very much at the heartof the Hythe
community, with well attended servicesand regular music
concerts.
The prominent position affords visitors glorious viewsof the
English Channel with the French coast visibleon a clear day.
However it’s susceptible to on shorewinds sweeping directly off the
English Channel andinto the church entrance.
St Leonard’s is accessed by a set of ancient stone stepsleading
up to the porch with a second set of steps insidethe porch leading
up to the entrance door. For yearsthe porch was a significant wind
trap, with the colddraughts funnelled directly into the church
wheneverthe door was opened.
Discussions around building a new lobby had failed toreach an
agreement over a design that would meet therequirements not just of
St Leonard’s and the DiocesanAdvisory Committee but also the Church
Conserva-tion Trust and English Heritage. The most
practicalsolution was a glass porch but English Heritage were
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Conservation & Heritage Journal29
Below: St Peter's Church, Dunchurch; glass balustrade and
structural glass screen
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concerned that installing glass in the entrance wouldact like a
mirror when the sun shone, creating asignificant impact on the way
the church looked.
After much deliberation, the solution was found witha glass
lobby created with the use of anti-reflective glasswhich would keep
out the wind without reflecting thesun.
Ion Glass were commissioned to carry out theinstallation and at
their recommendation the moreexpensive anti-reflective glass was
specified only on themost obvious panels, keeping the additional
cost to aminimum.
A full height glass screen was installed to sit just insidethe
outer entrance, with a series of five fixed glasspanels and a pair
of double doors. A handrail on theouter side of the glass screen is
a benefit for parishionerspausing to catch their breath after
climbing the hill andthe steep steps to the church.
Inside, at the top of the next set of steps a pair offrameless
glass doors with an arched over panelprovides a secure and
welcoming entrance to thechurch, with the glass set over the arch
to minimisethe impact on the original stone structure. The
originalinner door to the church now sits permanently
open,affording a welcoming view of the interior at all times.
The wind pressure on the structure added to thechallenge of the
installation; technicians at Iondesigned an angled head frame with
baffles and ventsto deflect the wind ensuring the doors don’t blow
open.
Each section of glass was individually templated toensure a
perfect fit against the uneven surface of thestone, especially on
the floor, where centuries of usehad worn the original surface into
irregular dips andtroughs.
Peter Hazeldean of Ion Glass comments: ‘The beautyof this glass
installation is that it is both functional andsecure, keeping out
the wind without in any waydetracting from the appearance of the
church. The useof minimal fittings to hold the screen in place
alsomeans that it has no impact on the way the churchlooks as you
walk up the hill, which is really importantwhen it’s such a major
part of the heritage of Hythe.’
But it’s not just about keeping the wind out, structural glass
is just as effective at keeping theheat in!The Church of St Nicolas
at Great Bookham datesback to the eleventh century and heat loss up
theancient West Tower, combined with the draughtsaround the wooden
door meant that heating thechurch was both difficult and
expensive.
A glass screen across the full width and height of thenave was
designed to completely separate both the
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Above: St Leonard's Church, Hythe Glass Entranceway
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tower and the entrance from the main body of thechurch. Ion
Glass were commissioned to ensure thedesign and installation of the
screen would haveminimal visual and physical impact on the
structureand appearance of the church.
A series of clamps were used to fix the panels of glassto the
hand-hewn stonework of the arch and glass finswere used to
stabilise the screen. Whilst thisconstruction was technically more
complex, the resulthad little impact on the fabric of the church
itself andmeant that there were no cumbersome fittings aroundthe
screen to detract from the view of the altar whenvisitors first
entered the church. Detailed lasermeasurements of the arches,
combined with theaccurate use of a templating comb, ensured that
theglass was precisely manufactured to fit around the
stonecorbels.
‘In order to meet the heat retention specification wewanted to
achieve a gap between the stone and theglass of no more than 6mm’
said Peter Hazeldean, ‘itwas a difficult brief and we were really
proud of theresult.’
The new screen was combined with a pair of outer glassdoors,
sitting just inside the existing wooden entrancedoor to the church,
creating a more welcomingentrance with a view of the interior, as
well aseliminating the draughts that had plagued the parish-ioners
for centuries.
Structural glass offers a contemporary solution toexcluding
draughts and improving heat retention inchurch and heritage
buildings. To achieve the bestresults with respect to aesthetics
and the impact ofmodern construction methods on ancient buildings
it’swell worth engaging a specialist company, not just fortheir
design input but also to benefit from havingskilled and experienced
technicians installing the glass– heritage buildings deserve a
sensitive approach on somany different levels! �
For more information about structural glass installations in
churches and heritage buildings contactwww.ionglass.co.uk or call
Ion Glass on 0845 658 9988.
Conservation & Heritage Journal29
Opposite top: St Nicolas, Great Bookham; glass screen with
structural glass fins
Opposite middle: St Leonard's Church, Hythe; glass structure
with double glass doors
Opposite bottom: St Thomas of Canterbury, Basingstoke;
glasslinkway connecting the church to the new parish hall