Creating high-quality, sustainable and affordable headquarters for The Salvation Army
With the usefulness of its various London premises coming to an end, The Salvation Army commissioned a new headquarters for its staff in the Denmark Hill area of the capital. Founded on the principle of offering soup, soap and salvation, the SA is keen to provide value for money to its supporters. The charity therefore wanted a cost-effective, high-quality building with a frame that would last for 120 years.
Additionally, the client wanted to ensure that the building was a welcoming workspace in keeping with its surroundings, including William Booth College which was built in 1929.
This design brief made concrete the ideal solution for the frame. Not only did the material work out more cost effective than steel, but it also offered increased headroom and enhanced visual appeal.
The new HQ comprises of six floors of largely open-plan offices centred around an atrium. Having chosen concrete, the challenge for the team was to come up with a design for the nine-metre spans running from the exterior facades to the central atrium. A flat slab would be unusually deep and heavy, while adding extra support columns would have obstructed the natural light.
By opting for a ribbed design for the slabs, the team allowed the light to flow while reducing the weight, amount of concrete used and the embodied carbon involved. This choice was largely responsible for a 30 per cent saving on CO2 per square metre of floor space when compared with an equivalent steel frame with composite concrete and metal deck slabs.
Rated BREEAM Excellent, the HQ also includes other sustainable design features. Since it has no false ceilings, the building benefits from concrete’s thermal mass, reducing the need for air conditioning in the summer and heating in the winter. This technique works alongside air-source heat pumps, which are powered by 90 solar panels on the roof.
Concrete also played a key role in making the HQ a welcoming place to work. The ribbed slabs help to create a sense of quiet and calm in the open-plan scheme, disrupting the sound reflections caused by the hundreds of people working in the building.
To keep the space in tune with the neighbouring college buildings, it features a brickwork façade, which — despite appearances — was also constructed using concrete. This offered a quicker-to-build, more stable alternative to traditional brickwork.
With The Salvation Army having supported communities in London for over 150 years, the durable and sustainable HQ offers the perfect space for the charity to continue its work well into the next century.
Image credit, Jack Hobhouse