Project Capella is a £79m new biomedical research laboratory at the University of Cambridge being delivered by Kier. This state-of-the-art facility is positioned between a number of other buildings, including the new Papworth Hospital. To reduce the amount of construction activity and disruption on site, a significant amount of construction activity took place off site.
A strategic decision was made early to use prefabrication rather than traditional construction methods because of the location of Project Capella on a campus where £1bn of buildings were being constructed concurrently. It required creative thinking to come up with a solution which met the client’s aspirations for the building, deadlines, need to limit the amount of activity on site and also manage the availability of limited local resources. Kier was involved early in the process and BIM technology helped turn a concept into a reality.
The precast concrete solution we came up with helped the client with funding across different financial years. We also found that this option reduced the number of deliveries and vehicle movements to the site which was important for the City of Cambridge.
As a research laboratory, Project Capella, had stringent vibration criteria, far in excess of typical requirements. The obvious solution would have been an in-situ-pour concrete frame for this project but because supplies of local concrete were scarce, we required an alternative. Working closely with our specialist precast contractor and structural engineer, we came up with an innovative hybrid of precast and in-situ concrete.
With the structure being made away from site, decisions on where to place laboratory machinery had to be made very early in the process so there was engagement which included a large number of end-users and stakeholders.
By building 80% of the frame and façade off site, this contributed to a 20-week reduction in the timetable and brought additional benefits to site management, health and safety and sustainability. Kier oversaw more than 200,000 worker-hours without a single injury or near miss.
The structural frame was made up of 3,900 different elements. The use of prefabricated elements enabled the project to consistently achieve enhanced levels of finish required for exposed areas of concrete. The pre-glazed pre-cast façade panels led to the building being water tight much earlier than a traditional build, enabling earlier installation of facilities. What contributed significantly to timescales was the off-site production of stairs and a lift shaft, enabling these to be constructed on site at the start of the process, improving access to other areas.