The completed scheme provides a much-needed informal dining and social space for the college which fully capitalises on its scenic location on the banks of the River Cam. In addition to the construction of the Café space, we also carried out the renovation of the existing main and ancillary kitchens, as well as the renovation of student accommodation and improvements to the Buttery, including new flooring and refurbishment of toilets. Works included the provision of a new lift within the building, as well as a hidden external stair lift, rendering Old Court fully accessible for the first time in its history.

Methods of Construction:
The new extension is constructed using piled foundations with a ground bearing slab, cross laminated oak frame with infill cladding/brickwork and composite windows to the elevations. Roof works are a mixture of aluminium, zinc, single ply membrane and lead.

Internally, the new walls are constructed from both masonry and timber with whiterock in hygienic areas and paint finish to others. Flooring is a mixture of resin, vinyl, and stone tiling. All areas have been completed to an extremely high standard, with an emphasis on quality and longevity of materials.

Challenges:
Access to the works area was extremely challenging, with the enabling works required very complex. We;

• Created an access road through an area in which numerous tree protection zones were in place. When excavations commenced, roots were discovered and the protection zone extended. To ensure that it was installed successfully without threatening the roots, we undertook a re-design of the access road which ultimately saw it built up as opposed to dug down. During this time, with heavy plant unable to reach the site, we engaged our groundwork subcontractor to reduce dig 350 tonnes of soil with much smaller machinery and wheelbarrows to mitigate the impact of the delay in haul road construction upon the programme.
• Installed two bridges to access the working area within the North Passage. The most significant of these spanned the River Cam, connecting the Fellows Garden and the Masters Garden. This meant that the plant and machinery could access the working area without using Clare’s historic bridge, which is the oldest in Cambridge.
• Fun Fact: The 57m long bridge, which was built and craned into place overnight by a 500 tonne crane, sat between the Garret Hostel Bridge and Clare College Bridge: the oldest bridge in Cambridge. This meant 10 bridges formed the backdrop for the numerous Punting companies operating between Mill Pond weir and Jesus Green weir, instead of 9, for the first time since the 1960’s.

To avoid delays associated with rescheduling the installation of the timber frame, we worked out of sequence and installed stone lintels after the frame was complete. To achieve this, we developed a solution in which the lintels were moved into Old Court via tower crane in advance of frame construction. A bespoke scaffold and metal cradle were used to move the lintels into position. Working out of sequence in this way avoided a 6-week programme delay.

Old Court is a Grade I listed building. In order to deliver the works successfully and sympathetically, we;

• Worked closely with the Conservation Office and accommodated archaeological investigations as required. This included resequencing activities when historically significant finds were made during the works, allowing the project to progress in other areas whilst investigations were completed.
• Ensured that the new timber frame fitted against the historic fabric by undertaking 3D scans of the existing building. This ensured that the new frame was designed and built to a high degree of accuracy.
• Carried out temporary works to protect existing structures, inserting temporary supports to the bottom of H stair to allow excavations to commence, and supporting existing brick walls which neighboured the new River Room Café. We also underpinned the historic foundations of the ancillary kitchen as our works to this area required excavations two metres deep.
• Carefully deconstructed and re-built a historic wall which featured stonework which the college wished to retain.
• In areas requiring brickwork to be repaired, we sourced replacement bricks which matched the existing.

The North Passage is extremely as narrow, measuring 0.9m wide at points, which presented significant challenges in accessing and undertaking works. To manage this, we;

• Avoided the need for the deep traditional excavations that were originally designed for the narrowest part of the site through use of a thrust bore run of drainage. This was a complex operation which included relocating 2 manholes and probing the line of the thrust bore to break up any obstructions prior to the boring taking place.
• Made use of small plant where possible, such as a small excavator to carry out works to instate a new bin store.

Our works required complex interfaces with an existing medieval chimney. 2 flues of the chimney were utilised to provide mechanical ventilation to the kitchens. In addition to this, we formed a permanent fire escape stairwell, the upper part of which passed through the chimney. To access the chimney to create the fire escape stairwell, we worked out of sequence, enabling us to install a scaffold to support the structure, as well as other complex temporary works.

• The project was delivered on a live college site. We;
• Installed noise barriers during each exam period, screening off all openings within the building fabric.
• Utilised a slew restrictor on the tower crane, ensuring that no lifting could be completed outside the agreed safety zone.
• Liaised with the college’s fire specialist regarding installation of the site’s wireless fire safety system.

Once the main works were complete and the bridge was demolished there was a significant amount of rubble remaining within the Master’s Garden. To remove this efficiently, we utilised a bespoke barge for transportation of the rubble across the River Cam and away from site.

Environmental and Waste Management:
Sustainability was at the heart of the scheme, with solar PV, a sedum roof, and wood fibre insulation throughout to compliment the high volume of laminated timber and bespoke timber panelling.

Social Value:

• We hosted numerous events to publicise the scheme, including a topping out ceremony and a Cambridge Forum for the Construction Industry (CFCI) site tour.
• A Barnes Construction Management Trainee was employed on the project during its construction phase.
• Mechanical, electrical and carpentry apprentices were employed on the scheme.
• A work experience student was on site for 2 weeks, delivering social value of £976.

Testimonial:
“The College have found working with Barnes on a day-to-day basis, to be easy, they are considerate, helpful and the staff are always engaged and polite (from the Banksman to the Site Manager). There have been no issues in working around an active College building, and additional issues presented by Covid have all been successfully managed. The College Health and Safety officer has been particularly complimentary of the Barnes set up and working methods.
The College has no hesitation in recommending Barnes Construction to work in a College environment. They are a proactive company, who have come on board with the College’s aims and sought to deliver the project in the most practical manner, while maintaining value for money.”
Deborah Hoy, Estates Director, Clare College.