Extinction Rebellion captures headlines but the sometimes-awkward questions about what buildings and other structures really cost the environment are increasingly being asked by developers and construction professionals. The steel sector is playing its part in coming up with some of the answers.
As BCSA President Tim Outteridge says in his column in this issue of NSC, steel is not a cost but an investment. And that is in both cash and environmental terms. Steel is consistently proven to be the most cost-effective framing solution for multi-storey buildings in independent surveys, using significantly less materials in the foundations due to its relatively low self-weight.
In the future, when other buildings might be heading for demolition due to being worn out or being unable to be adapted to changing requirements, steel-framed buildings score sustainability points by being easy to adapt and easy to extend. If financial or other demands make demolition unavoidable none of the steel will be dumped in a landfill – it retains a value as scrap material is needed in the steelmaking process and steel sections can often be reused in another building. Many developers know this already, others might adopt a steel-framed solution for the first time after they drill down into the costs.
In this month’s issue of NSC the projects we look at all contain evidence of the whole life cost benefits of steel. The new Hilton Garden Inn on the edge of the environmentally sensitive Snowdonia National Park will be a four-storey, 106 bedroom base for exploring the Park and the rest of northern Wales, where steel was selected after a value engineering exercise revealed its cost benefits over alternatives. The site is a former aluminium rolling and casting works, now being regenerated.
Lower cost as well as a more sustainable lower building weight also swung the decision towards a steel frame at the 12-storey Building S1, the second of a pair of buildings at London’s King’s Cross, following closer scrutiny of what was originally a post-tensioned concrete design. Future change of use is accommodated by allowing in the design for additional steelwork to be installed if future tenants want an uninterrupted floorplate rather than the current numerous staircase openings and atrium.
At Eleven York Street in Manchester, an eight-storey building featuring clear spans and aiming at a BREEAM ‘Excellent’ rating, a steel core has delivered programme benefits, meaning the project team didn’t have to wait for a concrete contractor to finish its work before beginning the steel erection, as it was all part of the same programme. The use of cellular beams maximised floor-to-ceiling heights and having regular holes provides future flexibility for changed service requirements.
All of these show that investing in steel is also an investment in a sustainable future.