Haymarket Green in Edinburgh is an exemplar of sensitive and sustainable refurbishment to create grade A, low carbon flexible, office accommodation.

The practice’s extensive experience in urban and sustainable architecture helped to resolve two key challenges raised by a development of this kind.

The first related to the legacy of the 1960s building form, which is a poor neighbour to the adjacent Victorian townhouses due to its set back building line, abrupt change of height and utilitarian character. Bennetts Associates introduced a series of new architectural layers to the existing structure to address these issues. The massing of the resultant composition has been carefully controlled to relate to the streetscape and skyline, while the vertical rhythm of the expressed steel structure echoes the proportions of the neighbouring townhouses. At the rear of the building a new two-storey mews reinstates the former street pattern and provides a sunny courtyard as a focus for a ground floor bistro which will also help to reinvigorate street life in the area.

The second key challenge was to reduce greenhouse gas emissions from poor performing existing urban buildings. Haymarket Green is a case study of how future sustainable targets can be achieved within a challenging urban context. It shows how a comfortable, naturally ventilated building can be provided on a busy urban street. The solution is to introduce air predominantly from the quiet mews side and use both acoustically attenuated vents to the street side and stack chimneys to draw air through the building. This innovative solution was developed from Bennetts Associates’ Hampshire County Council headquarters in Winchester, where extensive computer and physical simulations were used to demonstrate its viability. This natural ventilation system was instrumental in the building achieving an A-rated performance (<15kgCO²/m² asset) with regards to the Energy Performance Certificate and achieving a target of BREEAM Excellent.

Detailed planning consent was obtained in 2007.