At the top of the green ladder

by Darren
At the top

What makes 1 Angel Square possibly the greenest building in the world?


Sustainability solutions have reached a new level of eloquence in the design and construction of 1 Angel Square, the Co-operative Group’s new head office in Manchester, England. Dubbed by some the most environmentally-friendly building in the world, it is crammed with groundbreaking environmental and carbon reduction technology.

1 Angel Square is the highest scoring BREEAM* “outstanding” new building in the United Kingdom with a score of 95.16%. In addition, it has achieved an Energy Performance Certificate (EPC) A+ rating and was designed to operate to a Display Energy Certificate (DEC) A standard, the first building of its scale in the United Kingdom to achieve all three these standards.

*The BREEAM (Building Research Establishment Environmental Assessment Method) is the world’s foremost environmental assessment and rating system for buildings.

Designed by 3DReid, the objective was to deliver a 50% reduction in energy consumption compared to the Co-operative Group’s previous Manchester complex and an 80% reduction in carbon, aiming to curb operating costs by up to 30%. The energy strategy applied a clear energy hierarchy that deals with reducing energy requirements through passive measures, the efficient use of energy and the integration of low- or zero-carbon technologies.

Groundbreaking engineering features include a double-skinned façade containing solar shading through a combination of horizontal ledges and glazing mullions to minimise heating and cooling throughout the year.

The atrium roof was designed to optimise daylight and since early daylight and sunlight modelling informed the physical parameters of the floor plan, no desk is put more than 7m from a window to minimise reliance on artificial lighting.

A series of measures have been adopted to reduce the artificial lighting energy even further, including the use of efficient luminaires, painting the concrete white to increase light reflectance, occupancy detection, and dimmable and daylight control that were added in order to tailor the energy demand in response to localised patterns of use and activity.

The thermal mass of concrete within the building is exposed to the occupied space and employed to act as a passive, thermal sponge that, with a night cooling control strategy, helps to reduce the amount of energy needed to cool the building. 

The ventilation air supply is provided through a series of underground earth tubes that act as an earth-to-air heat exchanger, and the atrium functions as a large air plenum to extract air from the building. Waste air is extracted over the balcony edge using the natural stack effect of the atrium, thus negating the need for space-hungry extract risers within the cores.

A pioneering heat and power system that is fed by pure plant oil is used to generate a low-carbon source of electricity, with the waste heat used to warm the building or to provide cooling using the absorption chillers. For example, the charge points in the car park for electric vehicles receive power from this system. Rapeseed from the Co-operative Group’s own farms is used to run the engine and the leftover husks of the crop are recycled into animal feed.

To guarantee low water consumption, a recycling system for the reuse of grey water, a rainwater harvesting system and low water consuming fittings were incorporated in the design.

The designers have addressed the issue of global warming using predicted climate data for 2050, so the building can cope with a potential three to five degrees increase in summer temperature and 30% more rainfall in winter. 

On top of it all, the company has created a green travel plan that has reduced single occupancy car journeys by 10% and increased cycling and walking to site. They have also introduced a programme of personal carbon usage tracking for employees to ensure the building is used as it has been designed, together with a building user app, which relays real-time user information on how the building is performing.

Full thanks and acknowledgement are given to 3DReid architects, www.breeam.org and www.worldarchitecturenews.com for the information given to write this article.

1 Angel Square facts and figures
• 30 470m² of office space accommodating 3 500 staff members.
• 14 storeys above the ground (two below).
• 70 metres high.
• Internal atrium as high as 13 double-decker buses stacked on top of one another.
• A café within the atrium provides communal focus and can be re-configured as a 400-person conference facility.
• A restaurant on the eighth floor with panoramic views over the city.
• A 275-person auditorium at the lower ground level.
• 151 car parking spaces.
• 23 motorcycle spaces.
• 105 bicycle spaces.

1 Angel Square contains:
• 1 948 precast concrete coffered slabs that make up the floors.
• 3 157 internal and external window panels that make up the façade.
• 10 500 data and power outlets.
• 70 000 access floor panels.
• Approximately 3 300 tons of structural steel.
• Approximately 22km of power cables.
• 6 150 metres of chilled beams (if laid end to end).
• 539 foundation piles, with an average depth of 18 metres below the ground.


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