The Glass Room, Blackhill House

Blackhill House sits in an outstanding, elevated position above Tay valley in Perthshire; it is a mid 18th Century Category B listed building originally built as an inn, serving the old drove road that passes just to the east.

The historic house has only small windows and low-ceilings however and a new space was desired that would make the most of the outlook across the expanse of lawn to the landscape beyond. It was agreed that a new extension on the eastern gable end was most suitable; in terms of its massing in relation to the existing house and also because it could utilise an existing door opening in the gable wall, providing access into the kitchen. The floor level of the proposed extension needed to correspond with the existing internal floor level, but this left it half a metre below the level of the garden which rises up around the house.

The concept of the glass-room was developed, where the new extension floor is excavated into the ground-plane and hovering above is a roof supported on an elegant steel structure. Between roof and ground is an enclosure of minimalist glass walls, detailed so as to appear to drop straight into the surface of the lawn and with the southern facade able to be drawn back so that this space entirely opens up to the garden. Low, tiled walls act as benches around the perimeter of the space and extend through the glass wall to define an external paved area and steps. A series of incrementally curved, birch-faced, plywood fins span across the width of the space, creating a shallow dome under which to sit and take in the view.