Faced with constructing a sinuous three-storey residential block on a site that had an average 45-degree slope, Rori Williams expected the big challenges would be making the logistics and the traditional construction methods work. If only it had been so simple.
The real beast was the massive continuous solar roof, an element that was not originally part of the scheme. He had to secure a raft of approvals for the trailblazing technology and the export of surplus power to the Grid, and then install and commission it. The widespread lack of expertise and knowledge on all sides meant he only just got the roof over the line a fortnight before practical completion, and was forced during the course of the scheme to make vast retrospective alterations to hollowcore floor slabs, load-bearing walls and the roof support to accommodate it.
Besides this, of course, there were all the common travails of construction projects to overcome. Rori negated the need for two tower cranes on site by adding bringing in more fill material to allow turnstile access for plant and machinery that serviced the site instead. It took more time to construct the overcuts for the fill but generated valuable programme, costs and logistics benefits.
His value engineering was effective and thorough. By beefing up the timber truss, he was able to mount the parapet cladding direct to battens, reducing the use of masonry and support steel. By adding masonry walls to the perimeter structures and supporting the floor slabs on extra beams, he was able to reduce the number of load-bearing walls and lay screed continuously, without breaks in the floor.
By inserting a steel structure with thermally broken plates within the walls, he was able to cantilever the balconies without resorting to hollowcore planks and thermal break joints. And he eliminated trench foundations with fill up to 6m deep by placing ground beams on shallow foundation caps linked to the retaining wall.