Collaborative Efforts Yield Award-Winning RHS Hilltop Facade Design
Hilltop School's architectural collaboration: WilkinsonEyre's design project
A harmonious blend of collaboration, teamwork, and innovation has marked the success of the facade design for RHS Hilltop - The Home of Gardening Science, an award-winning horticultural project in Surrey, England. This project, completed in 2021, brought together WilkinsonEyre, NA Curtain Walling Limited (NACWL), Schuco, and other key partners, with the technical series sponsored by Schuco shedding light on this collaborative process.
At the heart of the £30m building lies a 4,750-square-metre research and learning centre, organized over two floors. The facility comprises state-of-the-art laboratories, public exhibition space, teaching studios, an events hall, and new facilities for the Royal Horticultural Society's (RHS) nationally significant herbarium, science, and library collections. Surrounding the building are landscaped science gardens, or 'living laboratories.'
A fabric-first approach was adopted by the architects, resulting in a highly efficient envelope, low U-values, excellent airtightness, and well-considered glazing proportions to balance daylight and thermal performance. The materials palette balances the warmth of natural materials with the simplicity of exposed concrete and steel structural elements.
Sweet chestnut timber clads the upper half of the building's wings, with horizontal slot windows interrupting the rhythm of the cladding panels. At ground level, a cast finish of precast concrete, recessed from the timber cladding, serves as a plinth to the main building volume. Larger spaces, such as the events hall and café/staff hub, are articulated by more substantial glazed elements, denoting their function and providing wider views of the surrounding gardens. Timber brise soleil run across these glazed zones, limiting solar gain.
Schuco was identified as the supplier of choice for all glazed facade elements, including curtain walling, windows, doors, bi-folding doors, rooflights, and automated smoke and heat exhaust ventilation (SHEV). The facades and roof utilize high-performance Schuco window and door systems, all finished in RAL 7016 Matt. FWS 50 capped and FWS 50 SG (structural glazing) curtain walling covers the ground, first floor, and roof in 36 units covering around 700 square metres. AWS 70 HI windows are extensively employed on the ground and first floors, as well as the roof (23 units). The building also incorporates FWS 60 SG rooflights (29 units), ADS 70 HI swing doors (five single and 25 double sets), and ASS 70 FD bi-folding doors (one set).
The collaborative process between WilkinsonEyre, NACWL, and Schuco was instrumental in developing the facade design. During RIBA Stage 4, WilkinsonEyre engaged with potential suppliers, including Schuco, and suggested a number of indicative systems within the performance-based specification. Close collaboration between the architects, structural engineers, and specialty subcontractors ensured that the design intent was clearly defined prior to the tender stage and continued throughout the project. Full-scale visual mock-ups were procured for several building elements with the most difficult interfaces to resolve primary design concerns before the formal drawings were issued for review.
The geometry of the building, combined with stringent environmental and security performance requirements, posed a series of facade challenges. The complex geometry of the window and curtain wall systems includes both concave and convex facets, which are complemented by curved feature caps. Schuco provided the capability to accommodate the facetted geometry within their systems, while NACWL created a bespoke carrier profile at the transition plane between curve and facet.
The RHS Hilltop project is a testament to successful cooperation. The project team seamlessly integrated a range of different facade materials and interfaces, resulting in a truly striking building that sits harmoniously within its site and houses a world-leading horticultural scientific centre of excellence.
- The education and self-development center within the RHS Hilltop building, furnished with state-of-the-art laboratories, teaching studios, and a library, is a product of the union of science and technology, fostering growth in horticulture and environmental understanding.
- In the pursuit of achieving a harmonious blend between innovation and conservation, the RHS Hilltop facade design utilized both cutting-edge technology from Schuco and environmentally conscious materials, such as sweet chestnut timber, in a balanced approach that reflects the project's commitment to both education and the care of the environment.
