Phase 3B of the Battersea Power Station Redevelopment is a mixed-use scheme consisting of residential, retail and commercial uses. A large part of the development is located directly above the new Battersea Power Station tube station, as part of Transport for London’s (TfL) Northern Line Extension (NLE) project.
Phase 3B features a 13-level commercial building and the completion of a 16-level residential building, both by acclaimed architects Foster + Partners, a retail podium, and a three-level basement by Adamsons Architects, adjacent to the tube station. Phase 3B lies immediately to the south of the mixed-use, Grade-II listed, Battersea Power Station itself.
- A 5,000m² 3-level basement car parking facility for retail visitors and residents
- Two levels of premium retail along a new high street, totalling 2,000m²
- 23,000m² of a new commercial building over site development (OSD) above the new TfL Battersea Power Station Tube station.
- A 7,000m² extension of the phase 3A residential building
- The OSD has been designed such that the station below can be re-built whilst the building remains occupied.
Design and construction required close monitoring to ensure so that the station can remain operational below throughout.
Key Technical Challenges
The greatest challenges on BPS Phase 3B have been to add value to the project for Battersea Power Station Development Company (BPSDC) given the project’s constraints, including Complex Over Site Development (OSD) above Northern Line Extension (NLE). RBG led the approvals process liaison with NLE on behalf of BPSDC. RBG involvement included:
- A unique construction methodology was developed to facilitate demolition and replacement of the NLE station box at the end of its design life, whilst maintaining continuous structural support to the buildings over, sufficient for them to be continuously occupied. This avoided the need to include onerous and value-degrading clauses in commercial sales contracts. The solution also reduced temporary works steel tonnages by over 60%.
- The structural and geotechnical design has been developed to meet TfL’s strict loading and interface requirements, including tight deflection controls, and coordinated waterproofing solutions.
- An alternative sitewide basement design was developed by RBG, which relocated ramping systems and car aisles; this alternative design resulted in the deletion of some 5,000m² of basement area, with a negligible loss of car parking spaces. Aside from the reduction in basement dig the resultant reduction in basement extent reduced expected peak lateral movements of the NLE structure – during Phase 3B construction – from a problematic 27mm to circa 12mm. This substantially reduced basement construction cost for BPSDC, and reduced the risk of damage and fit-out non-conformances for TFL.
- Constrained site by existing TfL and NwR assets and BPSDC Phase 3 subphases live construction. A 4D Virtual Design and Construction (VDC) land assembly sequence incorporating construction logistics was developed by RBG in order to achieve an efficient handover of the construction site areas, yielding programme improvements for BPSDC, and logistics improvements for TfL. The VDC model was used as a critical communication tool during key legal negotiations between parties.
- Change of building use from Residential to Commercial:
RBG have developed a hybrid scheme for the piling and GF slab designs to provide flexibility to BPSDC to study both options and make a later decision on the development use.
RBG used parametric design tools to maximize the building floor area of the Commercial scheme taking into account the constraints imposed by the Northern Line Extension, leading to an increase in floor area of circa 7%.
RBG accommodated the change of use from consented residential scheme to separate commercial building, including revisiting the lateral stability design of the existing structure (Core D).
- BPSDC approach to go fast to market and achieve the earliest start on site:
RBG developed a top-down construction methodology, allowing an early construction of the ground floor slab on top of plunge columns. The GF slab provides a deck for construction logistics whilst construction of the substructure and superstructure occur, leading to a reduction in overall construction programme as basement and superstructure works could progress concurrently.
To achieve the required construction dates, RBG undertook the structural design ahead of the remaining design team, providing allowances for design development and periods of re-coordination to re-align the design with the design team without causing delays on site.
RBG Value Add
RBG developed the structural design ahead of the remaining design team to allow the client to go early to the market and start construction work on site during favourable commercial market conditions
RBG developed the design integrated with the construction methodology to facilitate an early start on site and progress with construction of basement and superstructure simultaneously
De-risk construction, including simplification of structural frame and basement stability, mitigating temporary work requirements.
RBG led the approvals process liaison with NLE on behalf of BPSDC
Geotechnical monitoring procedures reduced temporary works requirements and reduced basement excavation
Use of recycled materials – steel and concrete aggregates
Optimization of structural frame to reduce overall material quantities
Use of lightweight concrete to reduce structural loads.
GBP £650 million
Circa 125,000m2 of mixed use development including basements
Battersea Power Station Development Company (BPSDC)
(SP Setia + Sime Darby)
Foster + Partners
Robert Bird Group Services:
Virtual Design & Construction