Autumn start planned for new Southwark hotel on former college site

Construction of a seven-storey, 274-room Premier Inn on a former college site in Southwark close to London landmarks including The London Eye and the Royal Festival Hall, is set to start this autumn.  Clarkebond is providing civils, geo-environmental and structural engineering design, including, basement impact assessment, masterplanning support, a detailed flood risk assessment and flood emergency management plan, for the new hotel development.

The development, which received planning approval in March, includes a single basement level and 7 above ground level floors rising in two blocks within a dis-used former college site.  A link bridge structure will serve as circulation corridor between the accommodation blocks.  All the roofs will also be used as ‘green roof’ to provide further attenuation as part of the overall SUDs drainage strategy.

The development has a number of engineering challenges associated with a city-centre location, in a tidal flood plain, on a very constrained site and with an existing basement structure.

Clarkebond proposed a number of build form options for this development to deliver the best commercial value for the client.  The option selected uses a lightweight load bearing steel gauge framing system, to be supported off the proposed reinforced concrete transfer structures at both the ground and first floors for the two building blocks respectively.

The benefit of this approach is to minimise the overall building height and the resultant load onto the basement substructure foundation.  This will effectively allow smaller and shorter bearing piles and will also have the benefit of reducing the perimeter pile wall load throughout, especially in close proximity to adjacent structures.  Additionally, the use of the light gauge steel framing system will remove any thickening in the wall for a concrete frame system whereby the width of columns are likely to be wider than the minimum wall thickness within the separating walls between rooms.  This will further enhance the internal layouts without compromise from any projection. This hybrid framing solution will also have the significant benefit of optimising the build programme.

With the constraint of the overall footprint, Clarkebond undertook option studies on a variety of retaining wall solutions to maximise the basement areas. These ranged from traditional RC walls to contiguous bored CFA in-situ concrete piled perimeter wall as well as the final chosen solution which will use interlocking welded steel sheet piling via the Giken silent press installation method.  This method will have the benefit of maintaining the minimum room areas and also provide the necessary buildability allowance to form the basement within the footprint.  This solution also achieves the acceptable limits for noise and vibration in connection with the party walls matter.

In addition to bedroom accommodation, the 9141 m2 new build development includes a ground floor restaurant, fronting onto an inviting public courtyard and pocket park incorporating seating, sculpture and to offer a calm oasis within the hubbub of city life.

“This was a challenging site, but having undertaken options studies at an early stage in the development, we were able to drive the value engineering and, ultimately provided a cost effective build solution for the scheme well within the original budget,” states Clarkebond Regional Director Theo Tai.

Developer:  Frogmore
Project Managers:   Gardiner & Theobald
Architects:  Dexter Moren Associates
Engineers:   Clarkebond
Building Contractor:  Gilbert - Ash

* Images courtesy of Dexter Moren