Eastbourne Terrace, London, W2 – Phase 1, Demolition

YardNine

30 weeks

£2.5M

Eastbourne Terrace, London, W1

Location & Overview

50 Eastbourne Terrace was located on a significant site of 2,500m2 immediately adjacent to Paddington Station and the new entrance to the Crossrail Elizabeth Line. The structures included two three-storey blocks and a 1960s eight-storey tower. One of the low-rise blocks shared a link bridge with a retained office block, all of which were of reinforced concrete construction with a mixture of brick and stone-clad facades. The redevelopment will deliver an eight-storey office building with shops and restaurants at ground level and terraced housing at the rear, and will be of a highly sustainable design, adopting energy-efficient measures such as a green roof, photovoltaic panels, roof terraces, tree planting and the use of rainwater harvested from the roof. Nestling behind the office building, a row of seven new residential townhouses with concealed roof terraces add to the line of the historic mews, which themselves posed a site constraint. Live MEP plant, a UKPN substation with high-voltage service heads pending switchover and decommissioning, two major gas services and comms equipment belonging to BT, all required protection during demolition. Asbestos surveys, soft strip and asbestos removal was undertaken throughout the buildings. Demolition of two three-storey structures, an eight-storey tower block with a link bridge to a retained office block, ground bearing slabs and foundations was carried out using floor-by-floor methodology, with some manual deconstruction, and the use of long-reach excavators for the removal of the link-bridge. Temporary works were installed to enable demolition, including falsework, propping, basement retention, temporary screens and party wall supports, with site-won materials being utilised for the creation of piling mats and berms. The following enabling services were undertaken: bulk excavation, the underpinning of the majority of the site perimeter using pressure-grouting, creation of reinforced concrete crane bases, the pouring of the basement raft slab, drainage and attenuation. CFA piling was carried out at ground floor level to provide foundations for new residential buildings. Design development from RIBA stage 4. The construction of the basement box back to ground floor level, with the liner walls between lower ground and ground floor being poured against existing retained RC walls.

Work, Challenges & Solutions

We amended our logistics strategy to avoid HGV deliveries on Saturdays, therefore maintaining an excellent relationship during demolition with the local residents and businesses, which was to benefit the follow-on substructure construction in phase 2 of the project.
We worked with the Local Authority, Transport for London, and the Met Police Safety team to agree on the best-suited delivery and muck-away routes.
We used local merchant depots and recycling facilities, with our concrete supplier being only 2 radial miles away from the site, to reduce traffic movement and support the immediate economy. Local shops and cafes benefitted from our workforce’s passing trade.
We successfully protected an existing substation on site pending decommissioning by UKPN, along with two major gas services, comms equipment belonging to BT and a major sewer infrastructure, whilst coordinating the re-routing of HV networks.
We obtained approval from Transport for London, to continue work close to the London Underground rails, using approved methods, such as derating our crane by 25%.
We value engineered the use of CFA (Contiguous Flight Auger) piles as a cost-effective, quick solution (compared to the proposed secant piled scope) by recognising its suitability based on the relatively low loadings required by the proposed building.
Temporary works were reduced by retaining the existing basement walls and casting the new ones against them, requiring only a small amount of propping.
We incorporated into the methodology the reuse and adaptation of the existing structure (Structural Ramp) to create a vehicle gantry to provide access for the delivery and export of materials without impeding on the public domain.
Our Health and Safety Leader held a Mental Health workshop, attended by over 40 operatives using his training from ‘Building Mental Health’, of which we are members.
In excess of 15,000 tonnes of demolition arisings were removed from the site for recycling.

Achievements

We achieved a score of 43/50 from the Considerate Constructors Scheme, in testament to our management of the large public interface.