New-Build Academy, West Bridgford, Nottingham

Brief:

In November 2023, Rushcliffe Spencer Academy had been named as one of four winners of the Eco-School of the Year Award, which recognised its commitment to sustainability and raising awareness of environmental issues. Consequently, and very fittingly, the design of the new building included many important resource-efficiency features.

The main teaching block would be composed of a lightweight steel frame, covered with Siniat Weather Defence boarding. This would provide the substrate for an external wall insulation system comprising non-combustible mineral fibre insulation boards and an attractive weather-protective finish. In accordance with the DfE Schools Output Specification, this system would need to demonstrate a design life of at least 40 years and must achieve an A2-s1,d0 reaction to fire classification (EN 13501-1).

Low energy lighting systems also played an important part in the design, as did the use of modern doors and glazing systems that optimised the use of natural daylight and helped to prevent the transmission of heat.

Although intelligent scheduling sought to make good use of the school holiday periods, much of the installation work would take place while pupils were studying on site in nearby buildings. It was therefore incumbent on suppliers and all stakeholder partners to coordinate their efforts to minimise disruption and to ensure swift and safe completion.

Design and Specification:

The chosen EWI system comprised:

• Permarock Mineral Fibre External Wall Insulation: Dual density insulation boards, mostly of 170 mm thickness, all adhesively bonded and mechanically fixed to the substrate;
• Permarock Silicone^Ultra K Finish (textured render).

When combined with Permarock Silicone^Ultra K finish, Permarock Mineral Fibre EWI systems achieve an A2-s1,d0 reaction to fire classification and can be used on buildings of any height. The Schools Output Specification Technical Annex 2C: External Fabric dictates that “cladding on a school building with a storey 18m above ground level shall achieve Class A2-s1, d0 fire resistance or better.”  Similarly, it states that the same rating is required “where school buildings are prone to vandalism… for all special schools,” and for all residential areas of boarding schools.

The Permarock Mineral Fibre Insulation was supplied in boards measuring 1200 mm x 600 mm. Generally, they were installed to a thickness of 170 mm but other thicknesses were used as necessary to complete the detailed design. All insulation boards were affixed using a polymer-modified, cement-based adhesive and mechanical fixings.

Permarock Silicone^Ultra K Finish is a flexible, vapour-permeable render with an attractive textured finish. It provides durable weather protection and helps to maintain airtight facades that, in turn, help to ensure a thermally efficient building envelope.

With a hybrid binder system of organically crosslinked nano-quartz particles and silicone emulsion, it helps resists the accumulation of dirt. It also contains a preservative that inhibits the growth of algae and other organisms. Together, these technologies help to produce a finish that retains a clean, bright appearance for longer than conventional silicone, acrylic or mineral renders. It therefore minimises the need for regular cleaning and costly maintenance.