The Copper House – Redefining vertical roofscapes

Nestled on the outskirts of Oxford, the Copper House stands as an example of how technical knowledge and creativity can be used to solve problems, and the importance of thinking ‘out of the box’ during critical moments.

The roofscape, designed by Phil Morgan at Wyckham Blackwell Ltd, is for a visually striking home and spans two storeys and a 180m² rectangular footprint, blending form and function to create an energy-efficient living space that captivates onlookers with its bold design.

The approach

Due to the unique and striking form of the Copper House, Phil felt that a truss solution would offer a simple and effective way of creating its angular and unconventional façade. He achieved this by hanging custom-designed truss profiles vertically, allowing the carpenters to easily shape the crisp skirt of the building while maintaining sharp contours around the window and door openings and minimising the need for on-site formwork.

Challenges and Solutions

Such ambition will always be met with some challenges. One of the initial challenges was to ensure the ‘vertical ridge’ roofscape aligned around all four elevations of the building once the copper cladding was in place.

To achieve this, each truss profile was individually drawn, accounting for the 18mm plywood sheathing on top, accommodating the asymmetric angles, and maintaining the critical standing seam point.

In total, 22 different profiles were designed to form the four-walled façade, integrating sporadic abstract window and door openings. These were fixed to the building using framing anchors that were spaced a maximum of two metres apart.

Extended truss overhangs formed parapets, concealing a seven-degree pitch flat roof equipped with a large array of south-facing photovoltaic  (PV) panels. This design allows the building to function as a ‘habitable power station’ without creating visual pollution for the neighbours, as the panels are invisible from the ground.

The steep pitch of the trusses on the north-facing façade reduces the impact on neighbouring properties and forms the porch cover, while the projecting south-facing façade blocks high summer sun to prevent overheating and allows low-winter sun to generate solar gain.

The technological challenge

Limitations of the design software posed a challenge in accurately drawing a vertical roofscape. Phil utilised the Revit model and created as many sections as possible for each elevation profile.

CAD-drawings were key in determining the set-out levels for each truss profile that was drawn and entered back into the software; but as each profile was entered individually, it made the export to a 3D BIM model difficult. For ease of visualising each truss position, the team implemented a colour-coded system, for the construction drawings which indicated where truss profile changes and their respective levels.

The oversized roof overhang, which served as a sunblock and supported the gutter system, created another challenge. Phil profiled the trusses to include an extended bottom chord, and in collaboration with structural engineers, they were able to secure the frame to the building.

Health and Safety

The vertical roofscape with a bulge in the middle of the building and the confined site presented significant scaffolding challenges. With a leading-edge nearly one meter from the external wall, the team faced the risk of dropping trusses into an open void. To mitigate this risk, installers, secured the scaffold with inertia reel harnesses, and installed two to three trusses at a time, followed by a temporary handrail. This approach, with one person aligning trusses from the top and another from the bottom, ensured safety for the team.

Additionally, boards were fitted to the truss webs where possible to provide fall arrest, and careful consideration was given to follow-on trades responsible for sheathing and copper cladding.

Sustainability Measures

The Copper House is a highly insulated, high-performance timber-framed building that employs reflective membrane barriers inside and out, enhancing thermal values and ensuring very low air tightness. The shallow-pitched flat roof houses a large array of solar PV panels, which reduce the building’s carbon footprint by generating cost-efficient electricity without harmful pollutants.

Instead of using an intricate cranked steel frame, which would have been costlier, less time-efficient, and environmentally impactful, Phil achieved the architect’s vision with trussed rafters and engineered timber products. This approach minimised cold bridging and contributed to the project’s sustainability.

Lessons Learned

This project showed the importance of close collaboration among all members of the design team. From the architect’s vision to practical site installation, coordinating efforts was crucial to ensure workability and achieve the end goal. Allocating adequate time for each stage of the program was vital to meeting quality standards.

According to Phil: “The installation process taught valuable lessons. Should there be any future projects requiring a vertical roofscape, we are now equipped with the experience and knowledge for safe installation.

“Ultimately, this project demonstrated that nearly anything is achievable with timber. Even with the most unconventional designs, a timber solution should always be considered, as it often proves to be extremely beneficial.

“Wyckham Blackwell would also like to credit Timber Innovations Ltd, for the timber frame design and fabrication and their installation teams.

“Last, but by no means least, credit should be given to Adrian James Architects and to Sarah Shekleton, who kindly provided images of the finished property. Please visit Adrian James at www.adrianjames.com.”

About Phil Morgan

Phil is a Senior Designer at Wyckham Blackwell with 18 years of experience in the timber engineering industry; including 11 years in truss design and seven years in timber frame building design, Phil began his career as a Timber Frame Designer in 2006 and transitioned to truss design in 2013. His extensive experience provided substantial knowledge in timber engineering and a strong understanding of designing and evaluating prefabricated timber elements.