If you ever despair of the constraints thrust upon architects and builders by conservative planning regimes, take
inspiration from the example of the Bowles estate in
north-east London.
At the hub is Myddelton House, a late Georgian mansion surrounded by mature gardens in the heart of London’s green belt. Although the grounds of the house do not stretch to the horizon, the planting, including Scots pine and sequoia, places the estate firmly in the English romantic tradition. In the 19th century the gardens were developed by Henry Carington Bowles, later president of the Royal Horticultural Society. His work has survived and thrives under the custodianship of the Lee Valley Regional Park Authority, whose staff now occupy the house. Both garden and house are listed.
It’s the sort of historic context you might assume would be untouchable, but it’s proving no obstacle to modern architecture. For before the end of the year, the first building that visitors will encounter when approaching the house on its curving driveway will be a far cry from the sedate grandeur of Myddelton House. The Park Authority’s new office building, under construction, will be low, sharp, minimal and black.
The architects, Louise Goodison and John Pratley of Cazenove, have a track record of strong modern designs for community and public sector buildings. The constraints of a project in a leafy corner of Enfield are certainly different from their usual inner-city sites, but they’ve responded in a typically forthright manner with a timber frame building designed as an honest and appropriate addition to its setting. Cazenove won the design competition because it took very seriously the client’s desire to maximise the building’s environmental sustainability and, while clearly not to be constrained by it, to respect the historical integrity of the estate.
It took two years to satisfy all the stakeholders in the planning process but now the building is rapidly taking shape. The timber frame subcontractors, The Homes Factory, will soon be departing, leaving a chunky framework of glulam posts and beams for the main contractor to complete the building.
The two-storey construction sits long and low behind a screen of mature trees and shrubs. The western entrance opens to a double-height circulation space that runs the length of the building on its northern side, filled with natural light from above. The office space on the southern side includes open plan areas and partitioned rooms, overlooking the gardens. The shallow plan of the building east-west means that all these spaces also have excellent daylight. This design is also integral to the natural ventilation strategy – one of Cazenove’s key goals for the sustainability brief.
A lightweight, naturally ventilated office is certainly not a straightforward specification when we’ve all grown accustomed to air-conditioning. Although the client was keen to maximise the sustainability of the building, both they and the architect had to be convinced this approach would work in a wood structure. So, the decision to build in timber was only taken after extensive thermal modelling by the project building service engineers, XCO2, alongside structural engineers Alan Conisbee.
Any building designed today for a long life cannot base its performance on climate data from the middle of the last century. Consequently XCO2 ratcheted their modelling temperatures up 2Oc over standard assumptions, increasing the difficulty of achieving comfortable office temperatures all year round without resorting to air-conditioning. In the final design, southern glazing looks out over deciduous trees and eaves are deep to enable winter solar access but exclude the high summer sun. Automated roof ventilation is combined with manual controls at window level and the building form allows air to flow from the cool subfloor to the rooftop vents, with fan assistance to enable night-time cooling in the summer.
Careful attention was also paid to maintaining low energy demand in the winter by combining a warm building envelope with efficient heating. The building will have 300mm á
Ü of Warmcel insulation in the walls and high-performance timber windows from George Barnsdale. Space heating will be supplied at a relatively low (and therefore more efficient) temperature through OSMA underfloor heating.
All the timber for the building has been carefully sourced, bearing either an FSC or PEFC provenance, with the structural components and plywood sheathing supplied by Finnforest. During construction, with the frame fully exposed to view, the building was an excellent advertisement for the use of timber in commercial buildings, with timber posts, beams, sheer walls and internal details all on show. Only the steel fin plates inside the main timber connections spoil the party, a detail required by part A of the Building Regulations.
Sustainable buildings come in all shapes and sizes, built from a remarkably diverse range of materials. Nonetheless timber serves an aesthetic of sustainability better than most, thanks to its organic warmth and its evocation of life and growth. These qualities are not lost on Cazenove, which has kept the main structural components of the building on show, complemented by interior details in Douglas fir.
A timber building with a very low environmental impact feels like a worthy addition to a carefully tended miniature arboreal landscape. The workers who spend their time in the light, open spaces of the new building will certainly feel a greater connection to the gardens around them than those left in the Georgian mansion, for all its sturdy elegance.
But will the more radical outward face of the building be welcomed among its established neighbours? Only time will tell, but its very discretion, alongside the ostentation of Myddelton House, should provide a happy balance. The two buildings engage with the landscape in different ways: one modestly from behind a screen of trees, the other grandly from atop a small hill.
At the outset, some local conservationists insisted that the new building should be designed in the style of the original house. English Heritage would not countenance this and the design now has the support of all key local stakeholders. If all goes well, the contemporary development of the Bowles estate will become a model for the sensitive integration of historical and environmental priorities.
