Architects and ‘urbanist’ studio TateHindle has completed work on the new six-storey Salvation Army UK and Ireland Headquarters in Denmark Hill, London. This project saw the successful delivery of an elegant, sustainable cost effective new home for the charity, fit for a modern workforce, artfully reflecting the context of the adjacent Grade II listed William Booth College.
The new concrete, oak and panelised brick structure is organised around a light atrium; housing a public cafe, flexible workspace, informal meeting and breakout spaces, and a roof terrace providing panoramic views of the city. The external facade and massing reflect the training college’s brown brick, stone dressings and varied level buttresses – putting the new campus “directly in conversation with the historic William Booth college,” comment the architects. “In its totality, the building aims to leave an impression of the organisation’s rich history and deeply embedded moral principles, while also looking to serve a forward thinking, modern workforce.”
In keeping with Sir Giles Gilbert-Scott’s original design, the new facade is articulated as a series of bays dominated by robust brickwork, broken up with brick piers to deliver a strong vertical emphasis. The projecting brick piers and recessed windows were incorporated to give a feel of a solid brick facade when viewed from an oblique angle; whereas when viewed straight on, much more glazing is visible to ensure natural daylighting is maximised as appropriate to the orientation of the facade. The use of contemporary design features and materials, including high levels of glazing and GRC fins and panelling that acknowledge the stone detailing of the listed building, gives the building its own identity, and “a unique and contemporary feel,” say TateHindle.
The forecourt is designed to cultivate a stronger presence in the area and make the space more open and welcoming to the general public. Featuring a “softly inlaid” cross up-lit at night to cast the recess in shadow, as opposed to the light of the William Booth College tower cross, the architects hope the north westerly facade leaves a “striking impression of strong verticality, solidity and airiness that will please visitors and passers-by alike.”
Modern working
The new headquarters will bring a modern way of working to the 450-strong workforce, with flexibility for future change built into the design. Enhancing the space for wellbeing has been a central design consideration, manifested through the expansive internal atrium (aligned, through a glazed opening at one end, with the William Booth College tower), and with a connective stair running the full height of the building. The workspace is designed to BCO standards and with equality exemplar principles, which ensure full accessibility to all users.
An open plan layout, with circulation and break-out spaces clustered around the atrium and desks set back by windows, is designed to break down hierarchies and foster cross-department interaction and connectivity for the central hub, both horizontally and vertically. Quiet spaces, meeting rooms, and a tea point are discreetly located behind the main lift core. The top floor comprises mostly communal space with a prayer room, break-out seating, a large tea point, and a roof terrace with panoramic views over the city, for staff to use for reflection and rest.
An open-to-all cafe on the ground floor will provide training and mentoring opportunities through The Salvation Army’s Employment Plus Service. The public realm has been reconfigured in two parts, with the entrance space now accommodating focal trees, lawn and low level planting, and the southern landscaped space containing trees, planting, and small areas of pocket seating for staff to enjoy the outside air. Trees have been planted to replace those lost by the construction, and bird and bat boxes are placed within trees and integrated into the building’s brickwork.
Sustainability
Functional efficiency, longevity, minimising waste, and material efficiency were key considerations in the design development. A concrete structure was decided upon to allow a 120 year design life to be achieved. The facade has been optimised in order to ensure air tightness and a high level of insulation to minimise heat losses in winter and heat gains in summer. Deep window recesses and rooflight timber mullions minimise glare and overheating, with the open atrium space also venting warm air via AOVs.
Unnecessary lining and panelling was omitted to expose the concrete frame, allowing its thermal mass to be harnessed. Additionally, a ribbed slab was engineered with a very shallow depth (just 100 mm at the top of the ribs) significantly reducing the total amount of concrete used in the frame, meaning a lighter building that required smaller foundations.
Improved functional efficiency, using air-source heat pumps on the roof to the latest environmental and energy efficiency standards, will significantly reduce the running costs of the building. The roof level will accommodate sustainable technologies, including around 100 horizontal PV panels. No gas is used to minimise reliance on fossil fuels. Sustainable drainage, in the form of ‘blue roofs’, cover the majority of the building to reduce the impact of rainwater run-off and the risk of pollution to watercourses. Dual flush WCs, spray taps and low flow showers with water meters help monitor and reduce operational water use.
A Site Waste Management Plan was in place throughout the build to minimise construction waste, an important factor in the BREEAM Excellent rating which is targeted. In addition, 50% GGBS cement replacement is used in the concrete frame, using a waste product from the steel industry and improving the concrete colour as well as reducing embodied CO2 in the frame. The final embodied carbon of the structure is 297 kgCO2/m2, including foundations.This is a saving of 20% compared to a standard concrete mix, and 30% compared to a typical office structure of steel and metal deck.
Materials
A simple palette of good quality materials was chosen to minimise future maintenance and refurbishment works, and reflect the organisation’s “desire to house its HQ in a building that prioritises its values before aesthetics.” Glulam lining provides softening and warmth to the exposed concrete frame, according to the architects, as well as structural support to the atrium rooflight. The deep glulam mullions also diffuse the light in the atrium with a warm glow while minimising excess solar gain. Demolition waste from two smaller, low-quality buildings that previously stood on the site was reused in the build.
The outer facade of the building features GRC and brick cladding, panelised offsite and designed to respond to the principles and proportions of the college, alternating with large areas of glazing to provide transparency and light.
TateHindle, developing a long term relationship with the client, provided ‘cradle to grave’ oversight, assisting with site feasibility work on the new headquarters as well as the sale of the old.