Our £21.5m project for the University of Oxford at Castle Mill is well underway and is showcasing a number of key innovative construction and environmental initiatives which will be of interest to those working in the estates directorates in the higher education sector.
The contract to build the 350-plus postgraduate accommodation quarters involves the construction of eight student accommodation buildings, three gatehouses, several ancillary buildings, combined heat and power plants and substation, with a target of a BREEAM excellent rating.
Following in-depth research Longcross was effectively able to rework the whole original build model and present the OUED with a more cost effective and environmentally sensitive build solution. This was achieved without compromise to their original vision.
As an introduction to the development we have briefly outlined some areas of particular interest below. However we do hope that you will be able to visit us on site on Friday 21 September to see our ‘Innovation in action.’ For details of the Open Day please refer to your email invitation.
Directions to the Site from Oxford Train Station
Directions from A34 to Consolidation Centre (free parking)
Directions from Longcross Office
Directions from Longcross Consolidation Centre (free parking)
Directions from Seacourt Park and Ride
Faced with an unstable soft clay soil, a high water table and the proximity of network railway lines which ruled out the option of vibro-compaction, Longcross tackled the issue of preparing the site for development, appointing and working closely with Cognition Land and Water, a leading specialist in the land remediation sector.
Drawing on the most up-to-date remediation technologies, Longcross was able to significantly reduce the movement of materials to and from site. The soft clay was removed and a considerable amount recycled for use in the landscaped areas. The ground level was reduced by 200mm to provide enough granular material for the building slabs and any additional required was derived from by-products normally destined for landfill but diverted to site for reuse. Dry cement was rotivated within the ground to harden the existing ground conditions creating the ideal substructure for the slab foundations, the thickness of which we were able to halve from 600mm to 300mm.
Introducing the unique Fusion build system
It is our mission to continually challenge traditional ways of thinking in order to deliver the most cost-effective, high-quality and sustainable solutions for our clients. After considering the options presented to us we carried out extensive research to enable us to rethink the build process and logistics without compromising the OUED’s vision.
As a result we were able to replace the original concrete frame solution with an innovative modular building system which combines a pre-insulated, light gauge steel external wall system with internal load-bearing walls and a range of flooring options, enabling the creation of residential structures of up to ten-storeys high. This unique, Fusion frame system is a perfect fit for the development at Castle Mill and has meant that we will be able to complete the scheme more efficiently and to a higher standard than previously planned.
Use of this SIPS technology is minimising waste and is significantly reducing the amount of labour and materials on site - particularly beneficial on a project which is severely challenged by restricted access (see below). We are also able to operate cycle-to-work and park and ride schemes for all operatives on site as a result of the factory prefabrication, and have been able to introduce a number of additional sustainable technologies to the development.
The Fusion system has been extensively tested at BRE for all key structural, fire, thermal and acoustic requirements and has also been certified by BPS 2020 (No. ABP006) and IAB (IAB 06/0125).
Meeting acoustic challenges
The development at Castle Mill has to satisfy strict acoustic criteria and to meet these challenges Longcross has set up an off-site testing facility to prove the design and buildability of our proposed systems. This SAEF (scientific auditory experimental facility) is located on university land at Osney Mead, Oxford and has enabled us to carry out a series of practical tests, allowing us to successfully close out all details prior to the commencement of works. Additionally the testing facility makes it possible for us to demonstrate material samples and finishes both to our client and the planning authority in a much more practical and hands-on manner.
Overcoming restricted site access
Longcross has considerable experience of working within restricted site areas so was ideally positioned to take on the logistical demands of the long, narrow, 400m by 25m site which directly borders network railway lines. Access is via a single track road passing Oxford station and a children’s nursery, so open lines of communication with local residents and businesses are essential.
Use of innovative off-site construction methods is minimising disruption to the community and we are limiting traffic flow and our carbon footprint by using bicycles to and from site.
Working with the Crisis Café
Crisis is the national charity for single homeless people with one of its key centres in Oxford. They offer motivational support and life coaching to the homeless as well as tailored employment programmes and accredited learning opportunities in literacy, numeracy, IT and ESOL.
When works commenced we realised we had the perfect opportunity to team up with the charity. Their Crisis Skylight café is an award winning and accredited enterprise that offers a wide range of food and drink to the public.
Longcross invited Crisis to set up a satellite café within the site boundary giving the entire workforce the opportunity to buy food and drink at any time and in an easily accessible location. In return all profits generated are injected back into further education, training and employment in the local area.