Geoffrey Reid Associates’ (GRA) new headquarters in a converted 1950’s office block in the heart of London’s West End is more than just a new home for the practice. Because new buildings in the city only represent 1-2 percent of building stock at any one time, the firm wanted to demonstrate that existing buildings can be upgraded in sustainable ways.

 

GRA Director Andrew Leckenby says: “The whole country, and particularly London, has inherited tired, lackluster 1950’s style office buildings. However, they have great potential and we intended to show that our expertise can create a high quality, future-proof office environment.” The challenge – beyond aesthetics – was how to apply a sustainable strategy instead of taking a more traditional approach, which would have meant sealing the building, ducting in fresh air, and providing mechanical cooling and heating systems.

 

Aesthetically, the focal point of the 14,475-square-foot (1,350-square-meter) conversion is a new five-story entrance to the building. It incorporates a translucent glass tower with an illuminated elevator that yo-yos behind the glazed facade, offering a striking visual sculpture for shoppers on Oxford Street. Access from the elevator onto the office floors is over bridges that span across the five-story-high void. The steel framed bridges are finished with timber decking and handrails. Sculptural colored lighting that reflects off the white walls adds drama.

 

The open plan working studios include small team groups in defined cells, while still preserving cross communication on each floor. Each studio is provided with a dedicated breakout space for meetings, presentations, and social events.

 

An open gallery replaces what would typically be the reception area. The space doubles as exhibition space for art (by people both inside and outside the practice) and architectural events.

 

Project Architect Graham Reed says: “The aim of the design was to make a simple clear statement at the entrance to the building, which helps to express the activities of the office behind. As Hills Place is a narrow, dark street, our intention was to give a visual lightness to the building and express the vertical and horizontal movement with glass and light. Lighting is also used to express the tower’s purpose as a ventilation shaft by illuminating the ventilation dampers at each floor level. The lighting changes continuously, reflecting the building’s responsiveness to environmental conditions.”

 

Sustainable Strategies

 

Natural Ventilation

 

From the beginning of the design process, GRA set design targets to minimize energy use. In conjunction with service engineers Charterhouse Group, they developed a mixed mode strategy, which uses natural ventilation for the majority of the year, and static cooling to deal with internal heat gains in the summer. This maximizes the free cooling capacity available under favorable conditions, and offers a low energy, low maintenance, and sustainable solution for controlling staff comfort.

 

A continuous set of grilles set into the bottom of new replacement double glazed windows allows fresh air into the building, which is then directed by a plenum within a perimeter casing to enter office spaces at low levels. The air then flows across the spaces and is extracted out, at a high level, into two vertical stacks at either end of the office (one is the new entrance/elevator tower and the other an escape staircase). At both input and extract points motorized dampers, linked to the Building Management System (BMS), control airflow. The new windows can also be opened giving staffers added control of their working environment.

 

External Blinds

 

In addition to natural ventilation, external blinds control solar gain. These are linked to the BMS and solar sensors and are activated when necessary. They are also programmed not to open in winter months so that the office can take advantage of solar gain and reduce heating requirements. Manual overrides for the blinds enable a degree of control by staff should the conditions on different floors need different settings.

 

Chilled Beams

 

While the external blinds deal with solar gain and the natural ventilation contends with the internal heat gains for the majority of the year, there will be times when peak summer cooling loads cannot be met. To deal with this in as efficient manner as possible, chilled beams (also linked to the BMS) are activated when the internal office temperature rises above 23 degrees Celsius (about 74 degrees Fahrenheit). The BMS monitors the surface of the chilled beams and prevents condensation by maintaining the temperature of the chilled water above the dew point.

 

Heating

 

Fin radiators for heat are integrated with the fresh air inlets in the bottom of the perimeter casing and served from a gas-fired condensing, low nitrogen-oxide burning boiler. In winter months, the radiators will pull fresh air over the fins to pre-heat it before being distributed into the office space by the grilles at the top of the perimeter casing.

 

Other Measures

 

General, indirect lighting is standard T5 tubes set into a bulkhead fixed to the existing beams. Task lighting is used where higher levels are required.

 

Predominantly white walls and soffits maximize reflectance of both interior and natural lighting. The paint is primarily Aquamarijin Maril, made from non-poisonous renewable natural raw materials and free of noxious chemicals.

 

Water conservation measures include low capacity, dual flush cisterns in the bathrooms (even waterless urinals have been installed), and sinks have self-closing taps.

 

Stuart Barlow, Technical Coach at GRA, comments: “By addressing the issues of sustainability ‘at home,’ as it were, shows clients the relative ease with which environmental objectives can be met.”

 

Architect: Geoffrey Reid Associates

Design Team (in alphabetical order):

Stuart Barlow, Maria Burtenshaw, Isobel Carmona, Mike Dempsey, Glenn Holmes,

Graham Reed, Geoff Reid, Mike Taylor, Polly Walls

Quantity Surveyor: Boyden & Co.

Structural Engineer: Buro Happold

Services Engineer: Charterhouse

Main Contractor: Simons Interiors

External blinds: Solar Blinds

Chilled beams: Halton

Paint: Construction Resources

Photography: Geoffrey Reid Associates and Andrew Southall

 

Geoffrey Reid Associates has been in practice for over 20 years, and is considered one of the top 10 architectural firms in the UK. With offices and associations worldwide, the firm employs nearly 180 staff in the UK alone, working across a wide range of sectors from retail and leisure to airports and educational facilities. Current high profile projects include the new Farnborough Business Airport (home to the world famous Farnborough Air show), and London's prestigious Battersea Power Station project.