Wells House
We were employed by the Prudential Assurance Company to carry out the demolition, substructure and core construction works at Wells House on London’s busy Oxford Street. The seven storey, reinforced concrete framed building was built in the 1960’s and consisted of retail and commercial units with a car park on the roof.
The project was situated within the City of Westminster and was bound by Oxford Street, Wells Street and Adam and Eve Court with a number of sensitive stakeholders including a mixture of retail, residential and commercial properties.  Due to its city centre location, there was extremely high traffic, footfall and cyclists passing the site.
Technical Challenge
The demolition works were carried out using a top-down methodology.
 In order to minimise the noise and vibrations from the demolition activities, we utilised 20t demolition spec excavators fitted with pulverisers and cracker attachments. Once floor load testing had been carried out by our in-house testing team Swantest, and the building was fully encapsulated with scaffold, machines were lifted to the highest level of the structure utilising a mobile crane. The machines commenced demolition on a floor by floor basis across the footprint of the site with materials disposed of via list shafts. Exposed party walls were weatherproofed and temporary works were installed where necessary.

Wells House shared two party walls at the west and north of the site with 132-144 Oxford Street and Castle House respectively.  Party wall approvals were obtained ahead of the commencement of demolition works, and we liaised with all stakeholders, assisting our client in this process. Temporary works design was completed by Swanton Consulting, our in-house temporary works department.

Following on from the demolition works, we undertook the secant and bearing piles, with our haulage department mucking away 14,000m3 material which allowed for the substructure to be formed 10m below the footpath above.

Concrete works commenced in a  bottom up/blue sky sequence and we were highly commended for our attention to detail and finishes throughout.

The scope included the construction of a two-level basement and mezzanine floor installation. Their construction was sequenced in a way to make the programme more efficient and release the core construction early in the works.
A bespoke waterproofing system was also installed which was a combination of concrete additive, cavity drain and render applied finish to existing vaults.  Suspended slabs were constructed to ground floor allowing for the main contractor to commence the steel frame on completion of our scope. The core was constructed utilising a jump form rig which allowed for the required finishes specified by the employer and we completed the topping out of the core and substructure works in October 2021.

Throughout the project, we were in constant communication with Westminster City Council, London Underground, Transport for London, surrounding businesses and residents to ensure the smooth delivery and constant cooperation whilst works were completed.


Works commenced on site at the height of the pandemic (March 2020).  A thorough risk assessment was carried out and a site specific management plan was produced and regularly reviewed to ensure all works could be carried out safely and in line with government guidelines.

Summary of service
Establishment of site welfare facilities
Scaffolding and hoarding
Tower crane erection
Asbestos removal
Soft strip
Temporary works
Top down demolition
Secant and bearing pile installation
Bulk excavation
Basement construction to ground floor
Jump form core construction