Queens House has undergone a £10m refurbishment. The works include removal of the existing mansard roof; adding a new storey and new mansard roof; moving the lift core and adding an extension to create more lettable floor space.
The building is next to the London Underground Jubilee Line vent shaft and the tube line runs under the building. This effectively precludes adding in new foundations. So, we’ve had to do some clever engineering to prove that the existing foundations can support the proposed loads.
This is probably the 4th refurb of this late 19th century building and we keep discovering new challenges from these as the work progresses. For example, we found a base for some temporary works for the 1985 refurb where our new lift pit was to be built and there is an existing foundation under the new extension.
All of these issues have been successfully incorporated into our design.