Haworth Tompkins has sought to maintain the original charm and discretion of deck chairs set among the park’s trees
Regent’s Park Open Air Theatre
Haworth Tompkins Architects
Until 1976, when Howell, Killick, Partridge & Amis’s new raked auditoriums established a more permanent grounding, the seating at Regent’s Park Open Air Theatre comprised informal deck chairs set among the park’s trees.
In the latest phase of its 12-year involvement with the theatre, Haworth Tompkins has, as at the Young Vic, sought to maintain the relaxed, rough-and-ready feel of HKP&A’s work, while substantially upgrading the facilities, all the while trying to maintain some of the original charm and discretion of those deck chairs.
This was not an easy task as there were numerous trees to be retained and the new works are substantial: relocating the offices to the site, rebuilding the dressing rooms, wardrobe and workshops, and creating a new box office and sheltered seating canopy.
The architect’s strategy has been to imagine the new accommodation more as a series of protective screens, hedges and fences than buildings, such that over time they blend with the neighbouring trees into the parkland setting.
Externally the buildings are clad in rough-sawn, untreated FSC larch boarding, either unstained or stained black and at times spaced to form screens. Timber fins mask the windows and, shutter-like, create a lively play of protective kernel and revealed interior.
Internally, the buildings successfully balance the careful co-ordination of services and structural panels with a workaday, unprecious toughness. The panels are left unpainted throughout and are quite rough in finish (grade C), with knots left unfilled apart from at the front-of-house box office.
Services are generally surface mounted and finished in galvanised steel, with the main trunking routes hung from the soffit of the spine corridor, and ductwork exposed within the changing rooms. In order to simplify site works, penetrations in the panels were pre-cut in the factory.
Fire protection has been achieved through a combination of over-sizing of panels to allow charring, the selective use of plasterboard to form compartments and the application of an unobtrusive fire retardant to the circulation areas.
Foundations & Trees
The building’s walls and roof are constructed using cross-laminated timber (CLT) panels, manufactured by Stora Enso Building Solutions and engineered and erected by Eurban.
In addition to allowing a fast construction that would fit between theatre seasons, the lightness of the panels reduced the loadings on the foundations, assisting in creating a solution that would allow the architects to build remarkably close to the surrounding canopy while preserving the existing tree-root systems.
Central to this strategy was the use of piled foundations that minimised the extent of excavation required and allowed earth movement without affecting the overall structural stability.
A slightly thickened slab allowed the building to cantilever beyond the line of the piles closer to the tree canopy and gave a certain amount of flexibility to the final positioning of the piles following the excavation of trial pits.
A void former below the slab will allow ground movement caused by clay heave and tree growth.
Structural engineer Price & Myers
Services engineer Skelly & Couch
Quantity surveyor Bristow Johnson & Partners
Project manager Bollingbrook
Landscape architect Camlin Lonsdale Landscape Architects
Main contractor Ashe Construction
CLT sub-contractor Eurban