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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

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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Below: St Peter's Church, Dunchurch; glass balustrade and structural glass screen

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.

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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