How Essentia, working for Guy's and St Thomas' NHS Foundation Trust, completed an overhaul of the huge building.

Commended in the 2degrees Champions Awards 2015

The background

Guy’s and St Thomas’ NHS Foundation Trust had a once–in-a-lifetime opportunity to improve the appearance of Guy’s Tower, the tallest hospital building in the world, while also fixing 40 years’ of environmental damage.

The rationale for the Guy’s Tower project was simple – the building’s façade was deteriorating and a complete overhaul was needed. The concrete was in a poor state of repair and the windows were at the end of their life, resulting in negative impact on the building’s energy efficiency. To safeguard services to patients and ground-breaking research activities, something had to be done.

One of the key aims of the project was to improve energy efficiency and reduce carbon emissions. While the decision to re-clad Guy’s Tower was driven primarily by practical issues, it also offered an opportunity to address aesthetics, energy consumption and sustainability in an innovative way.

What did we do

Replacing every window, repairing damaged concrete and applying cladding to the façade of the 34-storey landmark building, one of the busiest hospital buildings in the UK, was always going to be a challenge.

Key changes:

• 8,000m2 of bespoke, hand-folded aluminium cladding specially designed to cover the existing concrete, adding additional insulation of 180mm;

• 12,000m2 of high-performance, double-glazed windows installed with solar-selective glass to control solar gain in the summer;

• Cleaned and resealed 40 years of environmentally damaged concrete, revealing the original ‘white’ cement and improving aesthetics;

• 48m2 of additional floor space gained per floor through removal of old façade;

This work was particularly challenging as essential clinical services had to continue uninterrupted, including those at the dental school, laboratories and research facilities.

The result

The project originally proposed demolishing the existing 34 storey building and starting again. A study by Arup found a new-build with the same floor area would have a carbon impact of 490kg/CO2/m2, while refurbishing Guy’s Tower and extending its life by another 30 years has a carbon spend of only 105kg/CO2/m2, a considerably reduced environmental impact.

Operational carbon saving was offset against the carbon of the materials used in the façade refurbishment to calculate the carbon ‘payback’ of the building. This revealed the carbon spend would be paid back in just 12.5 years – less than half the minimum life of the façade. During a 30-year lifecycle, over 8,000 tonnes of CO2 will be saved through the improved thermal performance.

Re-cladding the Tower, achieved on-time and under budget with no missed clinical appointments, has increased healthcare efficiency and identified savings of £111,000 pa through reduction in maintenance and energy costs.

The personal pitch

The refurbishment of Guy’s Tower was a triumph of planning, process and perseverance. The ideas behind the project managed to be both practical and aesthetic – imaginatively and innovatively addressing the problem of the deteriorating façade, providing necessary insulation and thermal efficiency, and dramatically improving appearance. Guy’s Tower appears far more interesting and contemporary.

More so, the Tower is an excellent example of how the Trust embeds sustainability into the design of our buildings to ensure that they are comfortable, efficient and able to withstand the pressures of a changing climate.

Throughout the project, teams with diverse skill sets worked together under demanding circumstances to meet tight timeframes and budgets. The height of the building, weather conditions, and limited access made the task very challenging. The re-cladding of Guy’s Tower has achieved something very special – securing its future through a project that delivered on-time and under budget, which will benefit patients, staff and London for years to come.

Suppliers, contractors and solutions providers used

• Balfour Beatty - contractor • Arup – lead consultant, project manager, façade and structural engineer • Penoyre and Prasad - architects • Harsco – access and scaffold • Permasteelisa – façades • IronMan – metalworks • Kafften – concrete • Duffy – general labour and welfare • Rostek – roof works • Ductclean – asbestos removal • SEC – internal works • James Engineering – artwork structure