Permission was recently granted for an expansion and renovation of the 500-year-old Bath Abbey. A warren of vaults beneath the abbey will be linked together as part of the project. Feilden Clegg Bradley Studios
Planning permission has been granted for the expansion and renovation of Bath Abbey, in the United Kingdom.
April 2, 2013— Christian worship on the site of Bath Abbey, located in the English city of Bath, in the United Kingdom, has a history that goes back 1,000 years; the site as a location of worship has outlasted invading armies, the highs and lows of economic change, the country’s industrialization, and several wars. Construction of the current 1,500 m2 parish church—the third religious building to occupy the site—began more than five centuries ago in 1499. Church leaders now have their eyes firmly on the future, and this month they received planning approval to undertake the first extensive renovations and expansion of the abbey in 150 years.
“Context is everything on this project,” according to Fergus Connolly, the architect for the project with Bath-based Feilden Clegg Bradley Studios. Connolly responded in writing to questions posed by Civil Engineering online.
Bath is included on the United Nations Educational, Scientific, and Cultural Organization’s World Heritage List, and Bath Abbey is located in the heart of the city. The abbey is one of the United Kingdom’s finest examples of perpendicular Gothic architecture, according to Connolly. “Its masons are known to have worked on Henry VII Chapel, Westminster Abbey, and St. George’s Chapel Windsor,” he said. “As a grade I listed building, it is afforded the highest level of heritage protection available in England.” (English Heritage is the body responsible for classifying the country’s historically significant structures.)
Bath Abbey is located on a site that has been dedicated to
Christian worship for 1,000 years. The design team hopes to tie
in to the nearby hot springs that flow from the city’s Roman baths
to heat the abbey. Feilden Clegg Bradley Studios
The £18-million ($U.S.27.4-million) expansion and renovation undertaking, dubbed the Bath Abbey Footprint project, will include not only the creation of usable spaces to serve the expanding mission of the church (which sees 400,000 visitors a year) but also a technically difficult floor repair project and “green” alterations that will reduce the church’s carbon footprint and improve the comfort of visitors.
The abbey, like much of the city, sits atop a network of vaults located at various levels belowground. These occupy a space between the ground level of the Roman city of Aquae Sulis and that of its Georgian counterpart, some 3 to 4 m above, according to Connolly. “We were keen to understand the network of belowground vaults—both to unlock additional space for the abbey and to reveal an underexposed yet unique characteristic of this World Heritage city,” he said.
“With a wealth of history to deal with, the architectural concept was to reuse and celebrate that which was already there,” Connolly said. “Elements of the project have thus been almost curatorial in nature.”
Connective openings will be made to the “rabbit’s warren” of small vaults that encompass 200 m2 under the church to provide “clear axial routes through the basement network,” Connolly explained. The underground additions will include a newly excavated meeting room that can host 150 people, as well as new storage, dining, and bathroom spaces.
Aboveground, the abbey’s floor repair is “a huge technical challenge,” Connolly said. Approximately 5,000 people are buried under the abbey floor, the graves sandwiched in the 2 m space between the current floor level and the floor of the previous structure on the site, a Norman cathedral. Over time, the graves have subsided, causing uneven settlement of the floor and damaging the ledger stones that name the people buried and make up the floor’s walking surface.
Underground work will include a newly excavated meeting room
that can host 150 people. The project will also connect the abbey
to the church’s administrative offices to terraced houses that will
also be renovated. Feilden Clegg Bradley Studios
The current repair strategy is focused on keeping the graves in place while maintaining the ability of the floor to “breathe” and allowing natural cycles of moisture and salt movement to continue unhindered, Connolly noted.
Working with the civil and structural engineering firm Mann Williams, which is located in Bath, the team plans to scan for settlement voids using ground-penetrating radar, Connolly explained. The team will then make small openings along a grid of lines with a parallel spacing of 1.2 m so that a weak lime grout can be used to fill the voids via gravity. “This soft material will fill the voids but not form a bond with the archaeological layers—thus protecting them,” he said. “Once we have the surety of a solid subbase, a perforated concrete slab will provide us with the robust, flat floor structure required whilst ensuring moisture movement within the historic building is left unhindered.” Once this concrete slab is in place, the original ledger stones, which cover approximately 1,400 m2, can be relaid.
“Some of the damaged ledger stones are as sensitive as tissue paper,” Connolly said. “Our trial repair happens later this year, and the sensitivity of the craftsmen with whom we work will be critical.”
The abbey’s administrative offices are currently located in an adjacent line of terraced houses that were built in the 19th century for tradesmen. Even though the interiors of the houses have been renovated and altered in various ways over the years, the buildings are classified as grade II by English Heritage. The planning committee of the local council (formally, the Bath and North East Somerset Council) granted planning and construction permission for the project, which will include work to drastically alter the interior spaces of these terraced houses. A partially underground choral practice room of twice the normal height will be created by removing floors and walls and combining spaces, and stairways will be removed and spaces combined to improve circulation and accessibility within the offices. The terraced houses will be linked to the abbey via the recovered space from the underground vaults.
Floors and walls will be removed from a portion of the historic
terraced houses to form the new choral practice room. Feilden
Clegg Bradley Studios
Despite the concerns of various groups that the interior alterations could cost the terraced structures their English Heritage listing as historic buildings, the church demonstrated that the benefits to the community and visitors, particularly visiting groups of school children and choirs, would far outweigh any harm done to the original internal fabric of the buildings, according to the council’s report granting permission for the project.
Sustainability is integral to the Bath Abbey Footprint project, although it was not included in the planning permission granted by the local council. The Church of England, of which the Bath Abbey is part, is committed to environmental sustainability and is intent upon reducing the carbon footprint of its 44 dioceses and 16,000 churches by 42 percent by 2020 and by 80 percent by 2050, according to ChurchCare, a website of the Archbishops’ Council.
“It was clear from the outset that the abbey [was] ambitious to deliver a flagship scheme for the Anglican Church,” Connolly said. “Alongside considering photovoltaics on the roof and reducing the energy requirement through efficient lighting, insulation, appliances, et cetera, we were aware that a huge opportunity lay (quite literally) beneath our feet: The city of Bath is founded on the United Kingdom’s only geothermal springs.”
The hot springs leaving the Roman baths for which the city is renowned are channeled through a Roman drain next to the abbey that leads to the river Avon. “This equates to roughly 850,000 litres of water being flushed into the river Avon at a temperature of 40 degrees Celsius every day,” Connolly said. In conjunction with the local council and the mechanical and electrical engineers for the project—the Bath office of the global engineering firm Buro Happold—the architects have been evaluating the feasibility of using the hot water to heat the abbey through a heating system under the floor that would be integrated into the floor repair.
Connecting the geothermal springs to the abbey “would be a huge environmental and heritage success story for the United Kingdom,” Connolly said. “It would reconnect the geothermal springs and the city’s center of faith for the first time in centuries, and it is one of the best ways to ensure as many people as possible share the benefits of this extraordinary resource.”
The project is currently in the design development phase, and work at the site is expected to begin in 2015.