The living wall installation at the University of Oxford's Castle Mill student accommodation block illustrates how Biotecture’s fire rated living wall system is a workable reclad solution for the thousands of buildings in this country that are currently fitted with unsafe ACM cladding. Five fire rated living walls were specified at Castle Mill to replace the existing cladding, which created a stunning aesthetic and assisted the planning process.
Project Brief
The project partners were seeking fire safe cladding to satisfy visual amenity as part of planning and avoid having to undergo major re-construction works. From a building performance stance, a fire rated living wall was a prerequisite at Castle Mill because it would replace Aluminium Composite Material (ACM) cladding on the upper storey of the building.
Minimising the amount of rework meant that an effective method of fitting the living wall to the existing structure also had to be identified.
Castle Mill was located close to a Network Rail mainline which made this a challenging site, and representatives from the rail company had to be present whenever certain types of machinery were operated. Biotecture produced comprehensive method statements and carried out risk assessments prior to starting work on site.
There was added complication because Network Rail had established a fire route to the track close to where installation work would be carried out. This had to be maintained as a clear route at all times.
Highlights
- 530 square metres of living wall with 32,000 plants
- Fire rated living walls a prerequisite of the project
- Five living walls with five separate irrigation systems
- Installed on a constrained site next to a mainline railway track
Our Approach
Biotecture was able to demonstrate from an independent fire assessment that its BioPanel living wall system was a suitable rainscreen cladding replacement at the Castle Mill accommodation block. Reaction to Fire Performance of the living wall system is confirmed by a leading independent consultancy to be B-s3, d2. As a matter of right, this classification acknowledges compliance with the simpler BS 476 classification for spread of flame for which the system is confirmed to achieve class 0.
Another important factor in the success of the project was Biotecture’s technical ability to come up with designs and details that would fit with the existing architecture, together with methods for fixing back to the steel frame in front of the existing building.
Careful selection of plant species helped reduce the visual impact, effectively camouflaging the upper storey of this building. The most striking aspect of the foliage is its ‘shaggy’ appearance, which is exactly the aesthetic that the architects were looking for; it creates a harmonious juxtaposition with the branches of nearby trees.
These trees also created shaded areas on the living wall and Biotecture used its experience in plant selection to guide the architects to species that would remain healthy in the long term.
Approximately 530m2 of living wall was installed by Biotecture at Castle Mill over five locations, comprising around 32,000 plants. Five irrigation systems were also installed to ensure the long term health of the plants.
The completed building is very much in the public eye, visible to nearby residents, and observed by Network Rail passengers and commuters on nearby roads. The University of Oxford was pleased with how Biotecture approached the project and subsequently commissioned them to carry out ongoing maintenance on the Castle Mill living walls.