Jane Kennedy, partner in the Ely office of Purcell Miller Tritton (PMT), is an increasingly powerful figure in the field of building conservation. She has been surveyor to the fabric of Ely Cathedral since 1994, when she took over a £14 million repair programme, and is also in charge of conserving two of the six English buildings recently given World Monument status - Stowe School and Selby Abbey.
The looming presence of Ely Cathedral is visible both from Kennedy's office desk and her home nearby.A slim figure in her late 40s, Kennedy is tougher than she looks and one imagines that, in the Trollopian round of diocesan meetings, old-school clerics quickly learn not to mistake her calm self-possession for reticence. 'I have strong views and I'm prepared to stick my neck out, ' she says.
When appointed assistant surveyor in 1990 she was expecting to be treated as 'a chit of a girl' by the 'grand old men' of the Cathedral Architects Association, but they immediately welcomed her into the fold and she is now secretary.
Kennedy's approach to conservation is characterised by a strong sense of history, an interest she shares with her husband, John Maddison, author of a recently published history of Ely Cathedral. They married while studying in Manchester, where she fought pioneering battles with the Victorian Society to save places like Liverpool Road Station.
Exhaustive historical research is the starting point for all Kennedy's projects, to the extent that PMT architect Cathy Fisher is currently trawling the Huntington archive in Los Angeles to track down the original stone and sand quarries used at Stowe.
Kennedy also commissions archaeological investigations - including photogrammetry - and she routinely undertakes a thorough analysis of mortars. 'You have to understand the building's history, when it's been altered and why, ' she says. 'Then you can decide what to do now.'
In the case of Stowe, it was comparatively easy to fix the timeline for repairs to the 18th century, whereas at Ely, which had significant alterations by Gilbert Scott in the 19th century and Stephen Dykes Bower in the 20th, timelines for repairs have varied in different parts of the cathedral. 'Repair work at Ely can't be held to an essential point of time and it's more about balancing.'
In the case of some pinnacles on the choir, she says that she upset her masons by electing to stick with the 'rather bastardised details' introduced in an 18th-century repair rather than copy the medieval ones next door. 'My masons could see that the 18th-century workers didn't understand what they were doing, ' she says, 'but we put back what we found so that history was retained.' Her rule of thumb is 'if in doubt, keep to what is there'.
Kennedy's ability to steer a clear path through this kind of problem means she is increasingly in demand as an independent consultant for writing conservation plans.
These, she says, 'should be concise, readable and enjoyable documents', but all too often end up as 'huge, dull and very expensive tomes with vast numbers of checklists which nobody's ever going to read.'
In Durham, where PMT is repairing a tiny 18th-century parsonage house built with mud rather than mortar in the joints, she is impatient with local conservation officers' insistence on replacing the mud, even though the exterior will eventually be concealed by harling.
Unlike the growing band of historic building specialists who have taken postgraduate conservation courses, her expertise comes from the long route of varied jobs and 'luck in the people I've come across'. The latter include Donald Buttress, Andrew Anderson, architect for St Alban's Cathedral, and David Jeffcoate, the late SPAB technical adviser from whom she learned about lime.
Her career began auspiciously in the first European Architectural Heritage Year in 1975, when she spent her year out designating conservation areas for the now defunct Greater Manchester Council, but she has also done time as a freelance with small children in Norfolk in the early 1980s.
This included doing cottage conversions for friends, in one case for £50 and a turkey.
('Norfolk is good for barter'). Before joining PMT in 1988, she worked for Norwich City Council as a historic buildings architect.
Although working within a historic context is Kennedy's natural métier, she dislikes the idea of a 'battle of styles' between old and new. Architecture 'is to do with enjoying and understanding buildings and how they're put together, ' she says, 'and that applies to the Modern Movement as well as to repairing a medieval building.'
She has built two new buildings for King's School, Ely, and recently completed a new processional way at Ely Cathedral.
Thanks to generous gift donations, there was a surplus for the job of constructing much-needed lavatories, so these are now housed in a new single-storey link between the choir and the Lady Chapel. It was inspired by the discovery that there had once been a medieval two-storey passage designed to separate the clergy from the temptations of women among the laity.
Kennedy has had a lot of experience in managing teams of specialists, but it is the craftsmen from whom she claims to have learned most. 'We are very fortunate that in East Anglia there are lots of excellent trades who have never stopped using lime.'
The introduction of the English Heritage funding programme for cathedrals has made a great difference to long-term planning, and Kennedy backs the call for a second tier of national funding for large churches. 'There is a world of difference between a Tewkesbury Abbey and a parish church. Selby is jointly funded by English Heritage and the Heritage Lottery Fund, which is working well - with a big building you really need to plan ahead.'