The seven-story G.E. Fogg Building, a 1970s structure at Queen Mary University, had not aged well. The building provided teaching and biohazard laboratories for 70 staff and 1,300 students in the biological and chemical sciences faculty.
The building's leaky facade made it uneconomic to heat in winter. Extreme solar glare meant staff were erecting makeshift blinds to provide shade. The reinforced concrete frame was corroded. Windows were leaking.
The transformation of this tired university building in east London was an opportunity to show that unsustainable older structures can be upgraded to deliver industry-leading energy efficiency – without breaking the bank.
Mott MacDonald was retained as facade and building services engineer for the upgrade, working with architect Fraser Brown MacKenna. We set out to reduce the university’s operating costs and improve occupant comfort in a practical, sustainable, and economical way.
Leading-edge energy efficiency
We examined a range of solutions to reduce heating and cooling demand while maintaining stable internal conditions and came up with a threefold solution involving better insulation on the walls, high-performance glazing, and solar photovoltaic panels on the south and southeast facing roofs. To reduce solar heat gain, we initially considered installing fins to shade the facad,e but by opting for glazing that reduced solar thermal transmission we were able to do away with fins and reduce the capital costs.
The size of new windows was calculated to provide the right balance between natural lighting, ventilation and heat transmission. Windows making up a fifth of the total facade area can be opened to provide ventilation and natural cooling.
Generating renewable energy
We seized the opportunity to replace the building’s roof lights and windows with new glazing incorporating monocrystalline photovoltaic cells. The outer pane is a solar panel, while the inner pane is coated with a film that minimizes solar thermal gain.
By combining the cells into the roof light glazing and facade, we significantly reduced the cost. With the aid of government subsidy for renewable energy, the cost of installing photovoltaic panels was close to that of standard double glazing. In all, 1,292 square feet (120 square meters) of photovoltaic generating capacity were incorporated.
Working in a live environment
The upgrade had to be carried out while the university was in session, with teaching and research activities still under way. We worked closely with the university and contractor to develop a room-by-room decommissioning, handover, refurbishment, and recommissioning program.
By overcladding the existing structure with a striking new skin, we protected the structure from further corrosion, improved thermal and energy performance, included renewable energy generation, and reduced maintenance costs.
Thermal performance was improved by 65% for the walls and by 75% for the windows. Tighter seals on the new cladding and windows cut the volume of air leaking from the building by 35%, improving heat retention during winter. Combined, these measures cut the energy consumed by building services by 70%.
For a budget of £3.95 million, Queen Mary University gained a facility matching the best new build projects for performance at a fraction of the cost.