Vectos

Project overview

Vectos was appointed by St George City to provide transport and flood advice in relation to the Sainsbury’s supermarket site at Hendon. The scheme will replace the existing supermarket with a new store and construct 1,309 flats, 35% affordable, across 12 buildings. It will also provide cafes, restaurants, community areas, a new park and landscaped podium gardens.

The site is constrained by fluvial flooding from the Silk Stream, which puts part in Flood Zone 3 and part Flood Zone 2.

Our approach

Transport: We worked closely with the architects on the site layout, with a strong focus on placemaking to create new public realm that allowed for servicing access without compromising the quality of walking and cycling routes.

From the start, the strategy was to maximise the sustainable travel options in order to limit the potential traffic impact on the A5. We successfully argued that prioritising pedestrians and cyclists was more important than capacity for general traffic during the traditional commuter peak periods.

Extensive discussions were held with transport officers from the London Borough of Barnet and TfL prior to submission of the application and during its determination. The project received planning permission in August 2020.

Flood: As part of the Flood Risk Assessment, hydraulic modelling determined the extents of Flood Zone 3 and 2, which showed errors in the existing modelling. This helped to reduce the flood constraint on site. A flood mitigation solution was conceptualised and tested in the new hydraulic model. This included design of external levels to allow water to enter and leave the site safely.

A large podium roof garden provided the opportunity to manage surface water runoff through the provision of a blue roof (beneath the gardens). This provided a very large proportion of the attenuation storage needed across the site to manage surface water runoff. It was supplemented with areas of bioretention and below ground tanks.