Swiss Cottage, London, NW3

Essential Living

1 year 6 months

£10.9m

100 Avenue Road, Camden, NW3 3HF

Location & Overview

Swiss Cottage, formerly an 150m x 150m office space, was to be developed into a 24-storey block of social housing and apartments. The development was located adjacent to Swiss Cottage underground station, with the Jubilee line tunnels running parallel to the site. We prepared and received LONO’s for scaffolding, demolition, piling and basement excavation. In addition, we prepared a CDS and obtained approval of our working methodology to avoid damage to the tiled entrance of the station, incorporating an extensive vibration and movement monitoring plan. John F Hunt engaged with the client two years before commencement, working on scheme development and preparation of documentation to obtain planning and approvals from key stakeholders, including LU. We attended planning committees and public consultations in an advisory role. This resulted in an agreed demolition methodology, and approval of pre-commencement documentation, allowing a seamless transition from pre-commencement to site works.

Work, Challenges & Solutions

Our works involved soft strip and asbestos removal throughout the buildings, followed by floor-by-floor, top-down demolition of four adjacent 6-storey structures using a range of specialised techniques due to the constrained location of the site.
This was followed by the removal of a substation, enabling works and temporary works to facilitate the excavation and subsequent construction of a basement box, removal of foundations, drainage, pumping chambers and attenuation tanks followed by pile probing and piling. During all these processes 6no. dust, noise and vibration monitors were placed around the perimeter.
The site was in close proximity to Swiss Cottage Underground Station, the Royal Central School of Speech and Drama, a farmer’s market, and parks. We built around the London Underground Limited (LUL) entrance to Swiss Cottage Station to protect it and liaised extensively with the TFL staff due to noise permeating down to the platform, and close proximity of the site’s scaffold protection to the station.
A Red Bus Route, which was one of the most difficult intersections in London, was just next to the site, therefore for vehicle logistics, we maintained a strict system of seven vehicles into site, and seven vehicles out of site.
Neighbourhood liaison was central to operations at Swiss Cottage and due to our approach, we were able to successfully complete our works. We remained on programme and saved money due to our swift continuity of works, with piling directly following on from demolition. We maintained a very positive working relationship with Essential Living, meeting with them regularly.
A Grade II listed statue from the site boundary was protected and temporarily relocated by us to the nearby leisure centre. Extensive tree protection was carried out and local artwork from The Winch Community Centre, with whom we maintained good relationships with, was displayed on our hoarding.
We removed foundations, crushed and reused the hardcore on site as a piling mat. Piling was conducted in close proximity to the Jubilee Line, and included piling to support an access staircase in Swiss Cottage Underground Station. We performed silent piling, using 42no. 1,800mm diameter piles at 45m deep, and 130 piles which were 750mm diameter. A basement retaining wall was supported by a kingpost system to enable the construction of the new basement, for which we provided a higher spec finish than the client had requested.
Jumpform construction of reinforced concrete cores to level 7 were then carried out, as was the construction of RC columns and slabs to level 7.

Achievements

We registered the Swiss Cottage site with the Considerate Constructors Scheme and won awards for our presentation and care for the community. During this project, we were awarded the certificate for performance beyond compliance.
We used living hoarding to help reduce CO2 emissions and assist with dust suppression. The plants acted as excellent dust suppressors and trapped PM5 and PM10, the main culprits in causing asthma and a myriad of health problems for city dwellers.
We engaged with the local community to deliver art workshops that formed the basis for the hoarding design on for the elevation adjacent to the main subway entrance.
Within the hording we installed electronic video health and safety signage.
Three workers from the local area were employed by us after advertising locally, and one still works for John F Hunt.