Manufacturer spotlight: PREFA Makes Sherwood Observatory More Sustainable
Discover PREFA’s aluminium roofing systems and see how they played a key role in revitalising the Sherwood Observatory Science Discovery Centre and Planetarium.
23 April 2025
How roofing and façade manufacturer PREFA’s sustainable systems became an integral element in the construction of a state-of-the-art educational facility in Nottinghamshire…
When redeveloping a historic site to house a new science discovery centre and planetarium, architects needed a system that could offer sustainability and performance while meeting the complex design challenges of a domed roof that would sport traditional features such as tapered panels.
Architects Anotherkind and main contractors G F Tomlinson chose PREFALZ (standing seam) due to its durability, sustainability, and malleable nature. In this showcase, PREFA highlights why aluminium roofing systems are the ideal option for new construction projects where sustainability is a must-have…
Sherwood Observatory Science Discovery Centre and Planetarium is an exciting development located in Sutton in Ashfield, Nottinghamshire. It was originally constructed in the 1880s as a brick-vaulted underground reservoir. This historical site has been reimagined as a state-of-the-art educational facility designed to inspire a new generation of scientists and engineers.
From 2023, a new development was constructed adjacent to the telescope atop the buried Victorian water reservoir, creating a 10m diameter planetarium and science discovery centre, and opened in January 2025.
Designing the dome
The domed roof of a planetarium is an integral part of its character, but it poses unique challenges to designers. Architects from Anotherkind worked with GF Tomlinson to identify a roofing system that could offer the durability, sustainability and flexibility required for the project.
They chose PREFALZ (standing system) in a modern P10 Anthracite finish. Due to the complex nature of the roof, the project needed to bring in a specialist traditional hard metal installer, BJ Unwin.
BJ Unwin combined traditional skills and quality craftsmanship to achieve the desired finish for the roof, which involved using traditional welts, flattened seams, swept ends and tapered panels. Some of the complex hurdles included setting out the domed roof and accounting for the tapered panels.
The metal was fitted over the winter months. For some hard metals, the cold climate adds complexity to the project because the installer would need to heat the metal before working and forming it. PREFA’s solution made installation much easier because it remains malleable even at low temperatures.
These panels weighed an average of 2.15kg /m2, including fixings, which meant less weight for the building itself and for the contractor during installation. This lightweight nature meant that PREFA’s solution was competitive in cost due to lowered transport and roofing sub-structure costs.
Aluminium is not only lighter in weight and more malleable, but it is also corrosion resistant and doesn’t rust. Adding to the durability and safety of the system is the fact that PREFALZ aluminium complies with reaction to fire classification A1, non-combustible. This is backed up by the recently awarded BBA certificate, providing that all-important third-party certification.
Throughout the project and following completion, PREFA’s industry-leading 40-year material and color warranty provides consistency to the build and peace of mind to the client.
Why an aluminium roof is the responsible choice
One of the most obvious attractions of aluminium is its sustainability. Of the one billion tonnes of aluminium produced in the last century, 75% remains in use today. Aluminium can be recycled infinitely to produce the same product, over and over again. Manufacturing new aluminium from recycled aluminium uses only 5% of the energy needed to make it from raw materials.
To put this more clearly: recycling aluminium saves 95% of the energy that might otherwise be used.
PREFA is committed to sustainability in its manufacturing process. Currently, 87% of the small roof formats from PREFA are made from recycled materials. Across all products, including PREFABOND and PREFALZ, the proportion of recycled aluminium is 77%. Additionally, 100% of the energy used comes from renewable sources.
In terms of roof components, PREFA achieves the best results compared to alternative products in relation to greenhouse gas emissions, with a figure of 3.36 kg of CO2eq/kg.
For building owners and architects planning to offset/compensate for the emissions of their projects, PREFA’s systems are compelling. To compensate for a PREFA roof weighing 400kg across the 40 years covered by its warranty, you’d only need to plant 3.76 trees.
Even more beneficial, Aluminium roofs maintain their value after installation. Once recycled at the end of their service life, the emission figure drops to just 0.76 kg of CO2eq/kg. That’s less than half a tree!
Specify PREFA’s sustainable roof systems
The Sherwood Observatory Science Discovery Centre and Planetarium’s domed roof is a testament to the aesthetic, environmental, and performance capabilities.
For architects, specifiers, and contractors planning new projects, explore PREFA’s range via NBS Source to discover the versatility and sustainability of aluminium roof systems.