When commissioned to design a new building, effectively the 'portal' to engineer Gifford's Southampton campus, Design Engine Architects was faced with an ostensibly simple yet practically very difficult brief. It was asked to remodel the campus and provide a building that could carry the name 'Centre of Excellence' without any suggestion of irony, while designing to achieve minimal environmental impact.
Gifford's previous main office on the site was in a 19th-century coach house. The new building consists of three distinct parts: the reception area, a new studio space of 1,100m 2 and a link between the reception and studio. Visually, the reception building, with its brick facade and pitched roof, harks back to the older building, Carlton House. The link, which joins the reception to the studio and provides vertical circulation, uses a more neutral architectural language, whereas the studio is predominantly cedar-clad. In this sense, one would almost describe it as having an imposed or suggested archaeology.
Externally, the buildings have the air of an 'art gallery', redolent of other concatenations of old and new such as Kettle's Yard in Cambridge (although one hopes Gifford's drawings are more accurate than those of Alfred Wallis housed at the Cambridge gallery). This breaking up of the building serves to reference the original context while remaining resolutely modern. It works well.
The buildings are all steel-framed, the simplest being the reception space, which is effectively a continuous double-height volume. The main studio space uses some innovative techniques, incorporating all the common main construction materials - timber, concrete and steel - in conjunction with each other, as is fitting for an engineering practice perhaps.
The timber-clad facade panels are also timber-framed and were developed in collaboration with TRADA. The cladding uses Warmcel 500, a sprayed insulation made from recycled newspaper that achieves a U-value of 0.12 W/m 2K and allows the panels to breathe, enabling water vapour to pass from the internal environment to outside. Windows supplement the rooflighting (on the second floor) by framing particular views. The external treatment of these windows - which, because they are positioned where needed, don't correspond to any particular grid or arrangement - is dealt with by a break-line in the cladding, visually linking together the windows while also providing a ventilation slot through which the cladding's 'transpiration' is facilitated. The control of the facade again recalls a sculpture gallery; the building really isn't saying 'office' at all.
Gifford is using its new studio to experiment. The ethos of its approach is based on an open, interdisciplinary office - not easy in a 19th-century coach house - but entirely possible in a purpose-built space. What was required then was minimal structural intrusion on the floor plan and the elimination of downstand beams in the studio. This is achieved by the use of Omnia, a precast concrete permanent shuttering, with a post-tensioned in-situ floor slab. The supporting steel columns at mid-span are tubular and use a steel shear cone.
A shear cone transfers the loads from cast in-situ floors to tubular columns. It consists of a fabricated steel cone (several sizes and angles are possible), truncated - cut off before it reaches a point. This has a circular steel plate welded on to stiffen it, and to this is welded a tubular sleeve. The sleeve is slid on to the circular column at soffit level and welded into place; the sleeve serves to eliminate local buckling in this column. When the floor is cast, the cone sits predominantly in the depth of the slab. Because the forces generated by a cone are membrane-tension and membrane-compression, it is extremely efficient at resisting shear failure (ie. a column punching through the floor). This allows the designer to specify a smaller diameter of column (compared with a reinforced concrete or a standard-steel UC, for example) and to reduce the overall floor thickness. Both of these attributes were exploited at Carlton House Studio.
These features thus predicate another approach to sustainability - a key feature of this building - that of reduced material use. The commonly recited mantra goes 'reduce, reuse, recycle'. By using sprayed newspaper as insulation, Gifford and Design Engine have also embraced recycling. Reuse (especially in construction) is often considered in terms of reclamation, but while the use of beams and columns from one dismantled building in another new one is well recorded, it is, unfortunately, not common enough for there to be a burgeoning market in second-hand steel.
So the steel for Carlton House Studio is from primary sources, though it does have recycled content.
Use of a heat pump ensures that the heat generated in the building by people and machinery is not wasted but is used to heat the building when this is needed. Overall, the environmental-control strategy uses natural ventilation coupled with extremely high levels of insulation. It is calculated that CO 2/year.
Coming back to the apparent simplicity of the brief, the overriding impression of the new building is one of extreme fastidiousness in the use of materials. It is obvious that every junction, joint, corner and surface has been considered and questioned: what does this do, why do we need it, how is it made, who will use it? The resulting building embodies construction technologies appropriately used, and an immediately understandable hierarchy of architectural languages that allows Carlton House Studio to be appreciated for what it is - a great little building that balances a contextual modern Englishness, red brick and pitched roof, with a kind of cedar-clad international style, without appearing either forced or dull. That the building also uses new construction techniques is the cherry on the cake.