Maidstone Girls Grammar School – The Helen Keen Building

Baxall delivered the Helen Keen Building for Maidstone Grammar School for Girls (MGGS), a new three-storey block housing general teaching spaces, specialist science classrooms and dedicated music classrooms. The new building supports the school’s Science department to deliver more practical lessons and enables the Music department to teach, rehearse and perform in specialist facilities. It also features a visitor centre providing easier access to the World War II tunnels situated below the reception area, supporting both educational enrichment and preservation of the school’s wartime history.

Design: The design for the new teaching block reduces operational carbon and exceeds Part L Building Regulation standards. Our in-house team compared the environmental impact of materials through RIBA stages 3-4, guiding specification choices. The main structure uses Modern Methods of Construction (MMC) with a closed-panel timber frame, manufactured off-site by Streif. We partnered with Streif’s team to optimise the specification, achieving external wall u-values of 0.17W/m²K, outperforming the Building Regulations standard of 0.35 W/m²K. Streif’s system achieves an embodied carbon footprint of 450-550 kgCO₂e/m²—a 25-30% reduction compared to conventional steel frame and masonry baselines of 650-750 kgCO₂e/m². Panels arrived fully insulated and boarded with Rationel windows and doors pre-fitted, reducing site deliveries and waste. The C24 KVH solid timber frame is 100% PEFC certified and treated for durability. We achieved 99% waste diversion from landfill.

We enhanced efficiency with passive strategies such as natural/ hybrid ventilation units with heat recovery, maximised daylight with carefully planned window arrangements and specified LED lighting with daylight dimming and absence-sensing controls. The block’s east-west orientation limits heat loss by avoiding large north-facing windows. We designed and installed a solar PV array delivering 16.97MWh of annual electricity. For the external envelope, we selected lightweight brick slip panels finished with Corium tiles, using 75% less material than traditional brick and providing a 100% recyclable solution.

Challenges: The new building is located 15m from a Network Rail boundary, with an unstable railway embankment adjacent, which posed a high risk of collapse during construction stage. We engaged a geotechnical consultant for embankment analysis and designed the works to avoid any new load of Network Rail infrastructure, extending embankment monitoring 50m beyond the new building. We installed 60 bi-axial tilt sensors in 3-lines, 3G solar tilt gateway, 50 manual monitoring targets/10 reference targets, AvaTrace vibration sensors at 20m intervals with dust monitored by PM10 sensors and automatic alerts set to Network Rail limits. Crane slew restriction limiters ensured no plant or load encroached within 4m of the boundary. Automated network reporting and remote monitoring allowed us to meet compliance requirements, supply live data and reports and minimise manual site attendance, maintaining asset protection requirements.

Live Environment: Working within a live school environment required daily coordination with MGGS staff. We provided regular updates including progress photographs, time lapse videos and monthly newsletters for MGGS’s blog. All works were sequenced around exam timetables to avoid disruption. We arranged weekly site visits for 10–15 students and teachers, and hosted specialised tours and presentations focused on embankment monitoring for Sixth Form Science students. The Steel Signing Ceremony took place with teachers, MGGS’s Business Manager and students, fostering a sense of ownership and lasting connection to the new building. We planned construction activities to support the Barracudas Summer Holiday Club (4-week summer camp), guaranteeing side road access for delivery lorries. The building was handed over five weeks early, allowing occupation upon the commencement of the January term. “Our appreciation goes to Baxall, whose professionalism and collaborative spirit were evident throughout the build”.

Logistics: MGGS is located on Buckland Road, a dead-end used by both MGGS and Maplesden Noakes School (situated on MGGS grounds). All deliveries were scheduled avoiding peak hours (8:15-9:30am and 4pm) to reduce congestion at peak school times, while large articulated vehicles and cranes arrived on site at 6am. We encouraged the use of public transport with Maidstone Barracks/Maidstone East Stations close by. Our approach received a score of 45/45 in the Considerate Constructors Scheme inspection.

Social Value: Baxall donated £2000 towards the new WWII Visitor Centre, hosted a careers talk to Year 10s covering construction sector roles, and attended the sixth form open day to promote careers. “The students definitely had some good things to say about your presentations, and hopefully we will have inspired a new generation.” MGGS Careers Coordinator.