Modernism joins the preservation club

St Fagans National Museum of History is an eclectic collection of Welsh buildings, each transplanted to this site just west of Cardiff ­before the country was overtaken by the forces of modernity. There’s everything from a farmhouse saved from floods made by a reservoir for Birmingham, to Gwalia General Stores struggling against supermarkets. There’s a Gabalfa prefab, a bakehouse and a powerful circular stone cockpit which became a slaughterhouse and garage before making its way here. Each exhibit is labelled and tended, furniture set out, fires laid. But until recently the museum itself, an accidental example of modernism, was the least cared for of all of them.

Percy Thomas Partnership designed and built the stretching main building through the 1970s. It is one of those sparing, elegant yet monumental sculptural buildings. It took visitors into the 40ha site, stepping up a level with a courtyard in the centre. In an outdoor museum with tens of other buildings, perhaps it is not surprising that this modern one was a chopped and changed without much strategy or respect. Later a café and loos were added to the front, squeezing the entrance for this most popular of Wales’ free attractions into a tiny lobby. The main entrance became a carriage park and the courtyard was neglected.

When Purcell won the job to refurbish the main building there were some important aims. To start with, a better building to welcome visitors, education rooms that could give relaxed working spaces to accommodate school groups, more gallery space and a bigger café. The architectural ambition to release the simple power of the building perhaps remained unstated but is there nevertheless, although some compromises with CADW, the Welsh guardian of listed buildings, are rather uncomfortable. So the later additions have been demolished, the courtyard roofed over to create an oversized entrance space, and new servicing run through the building. A new restaurant and permanent gallery has been added to the west and a large education suite to the east. 

It is again an indoor place of refuge at the outdoor museum, the new home of its archaeology collection, rooms for explanation and education, and the biggest cafe on the site.

Near the beginning of the project the building was grade II listed as ‘one of the foremost essays in pure modernism in Wales’. John Hilling, the original architect on the job, is proud to see his building listed. It grew, for him, out of a college thesis on outdoor and folk museums and when Percy Thomas Partnership won the project he begged to be part of it. He made concrete beams as slim as possible to replicate timber’s role in early houses.

The original architect and client visited Scandinavian projects – the 1963 Munch Museet, Oslo, and Louisiana Museum of Art near Copenhagen. That clarity of open and closed has been translated here, although any nuance of interaction with the landscape taken from the Louisiana museum was since lost. The external courtyard with pond was no longer visible and the relationship of the original building with the wider landscape undercut. It is not clear whether this will ever be reinstated: it now has a field of parking to its most open elevation and the original exhibition galleries have become, for the most part, greyed-out internal spaces. While large picture windows in the new galleries could connect with the landscape and exhibits, whether they last will also depend on the exhibition design. 

Purcell project architect Lee Griffiths started his career at Percy Thomas Partnership, before this Welsh institution was absorbed into Capita. He showed Hilling Purcell’s proposals as they developed. Like many sixties buildings of this style the building has a strong architectural expression. Long projecting beams run the depth of the front and back ranges, resting on elegantly muscular brick-clad piers. They make a rhythmic com­position for the facade with huge stretches of glass in ­between, which are now doubled glazed. Griffiths admires them, though with a little bemusement about how things were set out; each piece of new glass had to be cut on site as that seemingly regular structural rhythm varied by up to a brick length on some bays.

The long spans required heavy opening top lights, and with some questions about the strength of the slender original structure, fixing to the concrete had to be avoided. So changing top hung opening lights to ones hinged at the base was less structurally demanding. Griffiths had hoped to use just one actuator on these large pieces of moving glass but in the end two were required. With the removal of later additions, a new roof and renewed flashings, the building has a clean composition again. Repositioning the entrance to the centre means that as you arrive the building is laid out handsomely in front of  you. 

The very clearly articulated original structure was designed in a different era of calculations. For largescale first floor exhibits – like one Celtic cross that reaches up through the 3m high beams – this meant reinforcing the floor before installation with new steel trimmings running across 1970s reinforced concrete beams. This cautious approach is also reflected in the structure of the bridge that crosses the enclosed courtyard, linking the education centre and galleries and one side of the portal frame for the new roof (there is an essay to be written on working efficiently with sixties structures). The ‘floating’ ceiling doesn’t quite appear to float as the layer of clerestories hung off the cantilevered ring beam need wide mullions to deal with lateral wind loading on the large panes. Also required was an internal retaining wall to hold up the rear range of buildings in the now-levelled courtyard. This reads like an oversized black plinth, the L-section concrete wall standing proud of the facade and foundations.

Another challenge was posed by the two ranges of galleries to the front and back of the building. In the Purcell scheme one range is being reused as a gallery, the other as three education rooms.  Each had double strips of clerestories on either side with a hessian-covered soffit on a V-section trough disguising sparse services running through the centre. In the most recent refurbishment, air conditioning was installed and many of the bays flattened into boringness. Bringing them back to their V-shaped character – sadly without the hessian – took the insertion of plasterboard and vents to allow for mechanical ventilation when necessary and extra steel Ts to ensure it would all stay up. The front range of galleries have been protected from relative humidity by glass walls to make partially enclosed lobbies above the main entrance.

All this consideration of detail and structure, as well as the significant extension, makes this building easier to appreciate as an ‘essay in modernism’ but not one that has quite regained the depth and nuance it was conceived with. Perhaps this was never going to be achievable with the increase in visitor numbers, and modern access and structural requirements. But archaeological objects from the city centre have a new home and the museum has a grand space for rent. It makes a functional, European-flavoured addition to this very Welsh institution.