Waddesdon Manor, a turreted Renaissance-style French chateau in the rolling Chiltern hills, was built for Baron Ferdinand de Rothschild in the 1870s. Today it is owned by The National Trust and is open to the public.

At the heart of the estate is Windmill Hill, a former dairy farm, where Stephen Marshall Architects has designed a series of buildings around two courtyards to house the Rothschild Foundation Archive and to provide office space for the charity investment organisation. The main reading room, offices and archive stores are open to the public by appointment and give access to one of the most comprehensive family collections in Europe. The original outbuildings have been incorporated into the project and the courtyards have been landscaped with reflecting pools and rolling lawns.

The use of timber on the new buildings – as both cladding and structure – was inspired by the original timber barns, which were generally clad with vertical boarding and roofed with huge timber trusses.

The accommodation is set around two courtyards, reflecting the footprint of the original buildings. The main entrance is a formal approach; a short flight of steps leads through a gap in a endered wall and into a formal landscaped garden that serves as the entrance courtyard to the project. On the north side a two storey barn-like building, clad with timber/render and covered with an overhanging zinc pitched roof, houses the charity investment offices.

On the south side, dividing the two courtyards, is the reading room, a magnificent space with a timber diagrid roof and glazed walls. The reading room consists of two large spaces, a conference space on the north side and an exhibition space on the south side, separated by a solid structure housing a series of reading alcoves lined with bookcases. The glazed wall of the conference space faces north to the entrance courtyard.

The glazed wall of the exhibition space faces south to the archive courtyard. The west side of the archive courtyard is formed by the archive store, a two-storey timber-clad barn-like building with high thermal mass and insulation, allowing it to be naturally cooled, avoiding the normal archive need for air conditioning and forced humidity control. It houses the manor, estate and family archive stores and the Foundation’s contemporary art collection.

The east side of the courtyard includes the original grain store and cattle shed which have been converted to a seminar room and plant room. The three sides of the archive courtyard enclose a lawn which rolls in waves towards the south side, left open to give views out to the countryside.