FCBS makes Bath’s Abbey and Roman Baths work better with invisible mending

Every city rests on the buried infrastructure of modern life – cables, metros, pipes and drains. Beneath the city of Bath there are also hot springs – the foundation of the city since the Romans arrived and built the warm Roman Baths which can still be visited today. In Georgian times the waters became a health and social draw. The now famous Georgian crescents were joined by assembly rooms, and investment in the spa infrastructure included a boilerhouse – to heat the natural spring water further from its standard 45 degrees – and a laundry. As the boilerhouse soot from the Somerset coalfield started to blacken the local limestone, so those who had lived out their hedonistic last in this social city were commemorated in Bath Abbey, just steps away. All 7000 of them, here is a rollcall of the society and of the colonial exploitation and the Atlantic slave trade that funded the development of Georgian Bath. 

Step forward to the 20th century and to Bath-founded, Stirling Prize-winning practice Feilden Clegg Bradley Studios. Over just a few years it won two projects to breathe new life into the Roman Baths and the Abbey. Both were large projects (worth £5 million and £10 million), minutes apart and largely invisible, much in the vaults under the city and serving the masterpieces of heritage that keep Bath’s tourist trade flourishing. The Baths and Abbey are also, rather wonderfully, connected by the thermal waters: FCBS’ Abbey Footprint project captures the heat from the millions of litres of water that bubble up each week – and were previously piped away through the Roman Great Drain to swirl in the cold waters of the River Avon – using heat exchangers to gently warm the Abbey floor.

Roman Baths Archway Project

But let’s start with the boilerhouse and laundry  – now a new education centre, the Archway Project, now officially named the Roman Baths Clore Learning Centre. I have experienced the Roman Baths, tagging along on a school trip, uncomfortable in a complex queue in a frenetic Georgian entrance hall, trying on togas and building mosaics with 30 children in a room smaller than the average classroom. The new entrance and learning centre will relieve a lot of pressure on the Roman Baths, and on the teachers and children who visit. It will also give a chance for longer running projects for those with mental health issues or disability, or for family engagement. It is connected to a new heritage centre for the whole city, with the same local authority client, Bath and North East Somerset Council.

More than that, the Archway Project will become part of the experience for them, made exciting by moves by the architect, unique access to archaeological remains, and a tunnelled route leading directly to the Roman Baths. Scrape and reveal techniques draw attention to the mix of buildings (boilerhouse, laundry with chapel, and stables), with old surfaces and remnants of large scale pipe work and new steel balustrades left naked. It is an architecture of texture and solidity with delicate interventions in the central circulation; this opens up to a double height space before squeezing students down the narrowest of stairs and passageways to reach a vault littered with Roman-worked stone, gradually unveiled by a dynamic lighting scheme. 

On the upper floors a lighter set of rooms reveal themselves, full of timber and unexpected delights. Cut into the exposed roof structure, a huge rooflight opens up views of the ornate boilerhouse chimney that is almost invisible from the surrounding streets. Deep window seats are cut into a wall, offering up glimpses of greenery and the Abbey between the buildings. 

Project architect Matt Somerville worked out the angle of the view on the model and is still delighted at what it captures in real life.  Another room is built up in giant steps around the cast iron columns of an old chapel, playing on its curves with a circular rooflight, a ring of lighting and a generous curving ramp running round one side of the room. These moves deal with problems like complex existing fabric, level changes and bringing in daylight, but are done with the gift of generosity and confidence. Equally, acoustic requirements by Building Bulletin 93 for the two education spaces have been dealt with using a combined solution of timber-framed secondary glazing and wall linings and decoration that includes vents, acoustic absorption and storage. Vitrines create dividers and pose as windows, enlivening walls. These are spaces of character and joy born out of complexity and calculation.

Bath Abbey, Footprint Project

The Abbey had many of the same challenges and a good few extra besides. The Footprint Project started with the Abbey’s collapsing floor, a repair job. And loos – during the busiest times worshippers had to head to the local All Bar One to relieve themselves. 

The 1620s Abbey – now Bath’s parish church – sits on the foundations of a larger Norman cathedral. In the floor were thousands of burials until was declared full in 1840, they are commemorated with 891 memorial or ledger stones there, or on the walls. In the 1860s, when George Gilbert Scott came along with a Victorian restoration, the stones were lifted to install heating vents and many of the skeletons underneath crushed before pews were installed throughout the nave. By 2010 the floor had become uneven, the stones subsiding over its rotted skeleton foundations and suffering in the damp trapped between the underlayer and the platforms on which the pews sat. Cracks had appeared in many memorials. 

The Abbey wanted not just repair but to make itself fit as a modern day place of worship and Christian engagement, and a part of civic society as the largest covered space in the city centre. As well as making the Abbey itself more accessible and flexible, the Footprint Project expanded to include dealing with the back of house. The offices were a warren of tiny rooms in the neighbouring Georgian terrace, the shop in the 1920s extension was overcrowded and the choir had to rehearse in a tight space alongside it.  Now the  terraces have been reworked and the circulation improved: the narrow staircase has been widened, and the complex of offices that it leads to has been opened up by driving a hole linking an enfilade of workspaces. It is all very practical and slightly worthy. 

But then, you open another small door and suddenly the floor falls away to reveal space below and above you. This volume of scooped-out terraced house has been turned into an oak-panelled choir room with a narrow balcony around the edge. There’s a grand piano, moveable stalls – designed by FCBS – music stands, shelves and cupboards of music.  In here 60 singers can practice. 

The choir school opens into the basement of the terrace. And rather than the choir donning coats and umbrellas over their robes to progress through the street to the Abbey, they now have a top-lit corridor under the pavement. As the terrace vaults run into the Abbey vaults the space opens up, interspersed with buttresses. A supporting concrete structure mirrors the arches of the vaults with timber insertions around door frames paying the same homage. Flags of a tough Pennant sandstone floor in varying scales echo the memorials of the Abbey floor. The new loos are already invaluable as visitor numbers pick up. The space will work for events and education, though it has to double as circulation for both air and visitors – as does the discovery centre awaiting fitout on the ramp between the vaults and Abbey. Passing through this leaves a sense of having missed the point of the architecture somewhat, but it will no doubt be remedied when in use. 

If you are looking for new architecture, the Abbey itself has something of the same problem. It is invisible without a guide. The most contentious move was in fact the removal of Gilbert Scott’s Victorian pews in the nave. This proposal led to a battle with the Victorian Society, a bruising and costly process, that the Abbey deliberately decided to make transparent with three days of the Church ‘court’ proceedings held in public – and making the project documentation open to all. FCBS’ and the Abbey’s argument that the pews were damaging the floor, inhibiting the mission and were, after all, only mass-produced factory pews, took a long time to win. There were in fact 30 separate approval processes, including some variations, for this project which is a scheduled ancient monument and grade I-listed with grade II listing in parts.

And then the hard work began with the stone floor. It was fully mapped and each of the thousands of stones, memorial or not, was taken up and inspected for repair – maybe bonding, maybe backing, maybe for replacement. A trial pit showed that the Victorian work had disturbed 1m deep below the floor so the Footprint Project worked within that layer, laying a new concrete floor slab to protect the remains, then pipes heated by the thermal waters and then the repaired stones. The 150mm fall in the floor level had to be addressed and it all had to be phased in order to keep the Abbey open throughout. The repaired stones relaid, in almost the same positions but not precisely. ‘It was a 3000 piece, 3D puzzle,’ says project director and FCBS partner Geoff Rich. ‘And you couldn’t even see all the pieces.’ 

There are more invisible moments in the Abbey: discoveries of a medieval polychrome floor, Roman coins, mosaics, and 46 Saxon skeletons. There’s a steel transfer structure to hold up the 50-tonne organ, a tea and coffee kitchen behind cupboard doors, power and data. More visibly, the Victorian lighting was relamped with LEDs, another move that will reduce the operational energy of the building. LED uplighters by the windows mean that the side aisles no longer descend into gloom.  

Invisible benefit

Both these projects enabled  historic buildings to stand in a better light than they ever could before. They use the best of the Roman Baths and Abbey, reaching out, under the pavements and into the drains, into their own foundations to make this city work better. Tourists may never see the difference but the experience of Bath will be better for it.

In Bath the RIBA Journal has covered Toppings bookshop along the street from the Roman Baths and Abbey and a very different sort of  refurbishment of a Nicholas Grimshaw factory into the heart of an art campus.

Lead image: Section through Bath Abbey. Credit FCBS

Archway project in numbers

£5m Total contract cost 
£3984 GIFA cost per m² 
1255m² GIA   
Traditional Form of contract

Abbey Footprint Project in numbers 

£10.05million Total contract cost 
1710m² Abbey ground floor
1621m² Vaults, chambers and terrace 
3331m² Total area 
3017 Cost per m²