Adam Richards Architects has created a robust but contextual learning centre on the grounds of Walmer Castle on the Kent coast. Photography by Brotherton-Lock
Tethered to its exposed site via the invisible force fields of its gun sights, billowing Walmer Castle stands alongside the narrowest stretch of the English Channel – in what is now seaside suburbia – as a visible reminder of looming insecurity.
It was built towards the end of King Henry VIII’s reign, after the break from Rome, to guard England against the perceived threat from ‘Popish Europe’, working with nearby Deal and Sandown Castles to close a gap in the defensive line of England’s south-east coast.
Adam Richards Architects’ new learning centre is part of English Heritage’s restoration of the castle’s 4.5ha grounds, a wider project that has reclaimed the Glen – a lost quarry wilderness now accessible for the first time in 100 years – and opened up new trails and play structures across the site.
The question for 21st-century architecture was how to conduct itself in the presence of a 480-year-old artillery fort set in a layered context of fine formal gardens and picturesque woodland dells. Should it pop up like a visiting guest or attempt to engage more robustly with history over the long haul?
The site’s architectural history didn’t, of course, start with King Henry VIII. The castle’s quatrefoil plan form probably originates in 12th-century France. As a motif, the quatrefoil – often referred to as Islamic in origin – appears in examples from Guatemala and Mexico that precede Islam by almost 200 years.
And neither did history stop at the time of the fort’s completion. From around 1725, the castle was incrementally domesticated as the residence of the Lord Warden of the Cinque Ports – latterly a pomp role whose incumbents number the late Queen Mother as well as prime ministers Churchill, Wellington and Pitt the Younger. Architecturally important interventions at the castle include adaptations by Arts and Crafts forerunner George Devey from around 1865.
English Heritage head of national projects Nichola Tasker explains that since the schism of 2015, which established the organisation as a charitable trust separated from the statutory role of Historic England, it has undergone a sea-change in its commissioning of architecture. ‘We were perhaps the client nobody wanted to work with,’ she says. ‘A bit vanilla?’
English Heritage has subsequently brought on board emerging practices including Newcastle-based Mawson Kerr (for projects at Hadrian’s Wall and in North Yorkshire), and William Matthews Associates (for the recently completed Tintagel Castle Bridge). It was Tasker who encouraged Adam Richards Architects to tender for the Walmer project, having visited its Ditchling Museum of Art and Craft in East Sussex.
The new building at Walmer creates a fresh presence on the site which engages in a direct conversation with the castle – albeit from a safe distance. The site for the building was more or less a given, extending an existing line of red brick 18th and 19th-century outbuildings that runs west from the castle’s main entrance to define the northern boundary of the garden. Part of the brief was to bookend this accretion of structures, including a lean-to glasshouse in need of renovation, with a new building that would provide multipurpose learning space within sight of the castle.
The learning centre is experienced as a discrete, orthogonal pavilion in dialogue with the bulbous fort beyond
Circling in via the processional route of Walmer’s formal gardens, the learning centre is experienced as a discrete, orthogonal pavilion in dialogue with the bulbous fort beyond. ‘I think the client had in mind a more camouflaged approach, initially,’ says practice principal Adam Richards, ‘but I felt we needed to create something that could hold its own as a piece of contemporary architecture.’
The rectilinearity of the new volume contrasts strongly with the curvature of the fort’s ragstone walls but, on the other hand, the grey-green hues of its diminutive hand-made bricks harmonise with the old colours as well as with the holm oaks dotted around the site.
The conversation continues with a window – a five-pointed arch – echoing the Tudor gun port clearly visible in the near distance (but also looking undeniably Islamic). A visitor might look from one to the other, caught in a conceptual crossfire.
There was a certain amount of architectural sorting out to do at the estate’s northern boundary, in view of the castle’s longstanding kitchen garden. A sharp new projection of boundary wall effectively resolves a back-of-house/front-of-house dilemma.
The act of enclosure also creates a backdrop, against which the foregrounded new learning centre is visually separated from old fabric – including the greenhouse, now retrofitted with a rear extension to create a café. The intermediary of a set-back WC block is clad in recessive dark zinc, its horizontal standing seams reading like the inverse of masonry jointing on a massive stonework façade.
The new buildings sit on a levelling plinth that doubles as seating, its heavy concrete sandblasted back to aggregate, contrasting with the nearby ever-shifting pebble beach. A shallow roofscape, overhanging expansively in places to provide shelter for the plinth benches, is also clad in zinc – in this plane, reflecting the light of the sky as well as reverberating with the castle’s low-profile covering of slate.
On plan, the play on geometries looks a bit tricksy, but in reality the psychological impact is strong: a separately articulated vestibule in deference to the main volume picks up the geometry of the site’s existing ancillary line, establishing an off-kilter entrance sequence which delivers visitors into a new hall with unexpected aplomb.
In this space a slot of uncentred raised roof lantern provides top light and reinforces the new shifted geometry, distracting initially from the magnetic pull of a side window with a view. ‘There’s a huge amount you can do on a subconscious level with architecture,’ says Richards of the interior.
Ultimately this is a building in praise of the window. How easy it would have been to widescreen the flank view of a yew cloud hedge, first set out by gardener William Masters in the 1860s, to mean virtually nothing.
The power of course lies in having framed the sightline for the benefit of visitors as a focused sideways take on a place and its history.
The window, explains Richards, functions like a giant museum display case (and has the effect of privileging the viewer as a consumer of a garden and its history).
It’s an inversion of a typical domestic bay, fabricated from a Schüco curtain walling system of the scale more usually applied to city skyscrapers, with hand-operated panels for natural ventilation slotted neatly into the side returns.
In a further allusion to the apertures set within the castle’s deep-sunk gun embrasures, three minor side windows steal oblique glances at the landscape.
The brief, says Tasker, was always about looking to the longer term. ‘We’re not expecting this to be a building that is just for 20 or even 30 years, the expectation is for a longer-term contribution, and that the building might one day change in use – like the castle itself,’ she says.
The sentiment is echoed by Adam Richards. ‘A lot of buildings are designed for a life of maybe 40-50 years,’ he says, ‘but architects are clever enough to do buildings that could last five to ten times longer while still being flexible into the future.’
The result at Walmer is a building that is modest in scale but ambitious in terms of life expectancy. In such a preserved, multi-layered historic context, the dimension of time takes on a new weightiness, and Adam Richards Architects has responded to the challenge with robust tectonics that convey the conviction that architecture is for keeps.
The buildings have been designed as a sequence of interventions with their own access route along the existing garden wall on the northern boundary of the kitchen garden to the west of the castle. The learning centre is a sculptural, single-storey brick building with a shallow-pitched zinc roof. It is contemporary in style, yet subtle in its language and deferential to its historic setting, with walls of hand-made grey brick which rise from a concrete plinth, sandblasted to expose the aggregate.
The new café is housed in a repurposed timber-framed glasshouse opening on to a Yorkstone terrace overlooking the kitchen garden. A low, horizontal, black zinc building with cantilevered roof canopies is positioned behind the existing garden wall to house the support spaces, including kitchen, toilets and plant room.
The listed setting constrained the use of visible renewable energy sources so the buildings were designed with a highly insulated building envelope and efficient building services, including heat recovery and mechanical extract ventilation in the WCs and kitchen, and natural ventilation via thermal stack effect in the education space.
We used a lime mortar in lieu of Portland cement. The new stair which leads down to the restored glen uses sustainably sourced air-dried oak cladding and opens up a part of the gardens which will be developed into a wilderness garden to enhance biodiversity.
The project involved a substantial element of tree management. Non-native species were removed and the woodland was enhanced with new planting.
Joseph Mackey, project architect, Adam Richards Architects
Whilst not being a particularly demanding project from a building services and technical point of view, there were a number of spatial and programming challenges. The small footprint of both the café and education building meant plant space was very limited and designs had to be reviewed and adjusted to ensure maximum operational efficiency.
To this end, a design was settled on to distribute electricity to all three buildings from the gardeners’ mess room, which contained the main switchgear for the site. Heating and hot water was generated by electricity in the gardeners’ mess room and by a gas boiler in a new plant room serving the café and education building.
Minimising the plant areas meant we had to run both mechanical and electrical services below ground between buildings on a very congested site. The works had to be very carefully planned to work with the phased construction programme.
The gardeners’ mess room proved to be particularly exacting due to the timescales of the project. In order to accommodate works on the rest of the site, this building had to be completed and handed over as first phase.
However, the main switchgear required complete replacement due to age and condition. Since this switchgear also fed the greenhouses, staff accommodation and holiday lets, the phasing of this replacement required careful attention within a very tight overall programme.
Neil Prowse, director, Martin Thomas Associates
The aim of the project is to enable visitors to engage with the historic gardens. We chose a small grey-green Petersen brick to reconcile the colours of the castle with the materials of the existing garden buildings.
The new building’s form responds to the dynamic sculptural mass of the castle while its large window opening transforms the shape of the castle’s five-pointed arched gun ports into a viewing-port on to the gardens.
Our five-pointed arch was fabricated offsite by combining a series of specially shaped bricks with a precast concrete element to the required shape.
The window is conceived as a giant museum display case, made from 3m-high Schüco curtain walling. Both the brick walls and the bay window rise from a concrete plinth, sandblasted to reveal the aggregate, which steps up along the length of the building following the topography.
This plinth refers to the character of 20th-century sea defences, and registers the nearby shingle beach. The unstable shifting material of the beach is transformed into the structural base of the new buildings, which in turn extends into a series of benches.
The window enables the new building to enter into a dialogue across time with the other buildings at the site. From the outside it acts in formal counterpoint to the geometic abstraction of the building it lights, while from the inside it places the landscape garden in the role of museum object, helping the building’s users to participate in the construction of meaning.
Adam Richards, director, Adam Richards Architects
Start on site February 2018
Completion June 2019
Gross internal floor area 200m²
Construction cost per m² £4,025
Architect Adam Richards Architects
Client English Heritage
Structural engineer Historic England
M&E consultant Martin Thomas Associates
Quantity surveyor Press & Starkey
Project manager English Heritage
CDM co-ordinator Adam Richards Architects
Approved building inspector London Building Control
Main contractor Walker Construction
CAD software used Vectorworks
Landscape designer Luc
Civil engineer English Heritage
Play equipment Studio Hardie
On-site energy generation Nil
Heating and hot water load 48 kWh/m²/yr
Total energy load 232 kWh/m²/yr
Carbon emissions 31.8 kg/m² (regulated energy only. From design BRUKL report)
Predicted design life in years Services: 25 years; Architecture: 100 years