Edinburgh Pavilion

Archer & Braun has extended an Edinburgh villa with an elegant stone and glass pavilion

Photos
David Barbour

Designed by Archer & Braun, Edinburgh Pavilion comprises the refurbishment and extension of a listed Victorian villa in central Edinburgh. Accommodating an open-plan, light-filled, kitchen and dining space, the highly glazed rectangular extension is located at the rear of the house, and is intended to contrast with the existing building. An axial view from the original entrance hall provides a glimpse into the extension and through to the garden beyond, which is accessed via large sliding glass doors. A frameless glass link separates the old and new structures.

Achieving a minimalist aesthetic through careful material specification and detailing was central to the design, writes Archer & Braun. We omitted superfluous detailing to reduce the extension to its fundamental elements. The steel structural system is designed to be discrete, with the columns set back from the facades and corners, and the glazing running past the roof build-up to create a slim coping detail. This required extensive coordination with the structural engineer, contractor and glazing and metalwork specialists.

Ground-floor plan; detail section

The stone walls of the pavilion are made from solid Corsehill, a warm red and fine grained local sandstone that has been used in some of Edinburgh’s most recognisable buildings, such as the Scottish National Portrait Gallery. Special care was taken in the detailing and specification of the stonework to ensure a contemporary and monolithic aesthetic. Large-format stones were selected from a specific stone band within the quarry, alongside matching flush mortar, which was also sourced from the same quarry. The new stonework is intended to reinterpret the array of traditional stonemasonry techniques used on the existing property. The primary garden elevation is ‘rubbed’, a technique that results in a smooth finish, while, the secondary elevations are grit-blasted. This technique was used as a contemporary way of referencing rough-effect traditional stonemasonry techniques, such as stugging.

For the sliding doors, we chose glazed units with very slim sightlines (20mm mullions) and no visible frames at the base. The metal sections are powder-coated a dark red tone to complement the stonework. Low-iron glass was specified to avoid a green hue across the relatively large expanses of glazing.

In terms of sustainability, it was crucial to use a material that is long lasting, robust and low in carbon. Natural stone, particularly when locally sourced, is a low-carbon building material compared with brick or concrete. It was also important to us to use solid stone (rather than cladding) to reduce the amount of concrete blockwork in the project. This required a lot of research and discussion with the quarry. Due to the amount of glass in the extension, solar control blinds were added to reduce the risk of overheating. The existing building fabric has also been upgraded with new windows, roof insulation, underfloor heating, electrics and low-energy lights throughout.