When it was decided that The Buchan School would relocate to the King William’s College campus, the design team faced a common choice: demolish and rebuild, or retain and adapt.
Two existing buildings - Jackson House and Stenning - were structurally sound, underused, and well-placed. Rather than clear the slate, the team opted to reuse and reconfigure. A full new-build equivalent would have embodied around 680 tonnes of CO₂e. The refurbishment, by comparison, is estimated at 190 tonnes[1]; an avoidance of 490 tonnes.
That saving comes from materials that weren’t demolished, concrete that wasn’t poured, steel that wasn’t fabricated, and envelope systems that were never required. In everyday terms, it’s equivalent to:
The annual emissions of 105 petrol cars[2]
The carbon captured by 800+ mature trees over 25 years[3]
The energy generated by a 2500 m2 solar PV system over more than a decade[4]
Adaptive Reuse in Practice
The retained fabric included loadbearing masonry, existing slabs, roof trusses, and selected windows and doors. Interventions were targeted and minimal: localised steel insertions, new partitions and linings, updated ceilings, and bespoke joinery to suit new educational layouts.
MEP Design In Support of Reuse
At March Consultants Limited, our role was to ensure that building services supported, rather than disrupted, the logic of reuse. Penetrations were kept minimal, distribution routes were adapted to the existing fabric, and services were carefully coordinated to preserve structural integrity. While many systems are new, they were selected for their compact footprint and high operational efficiency; ensuring their inclusion contributed meaningfully to long-term performance and energy savings.
The project features hybrid ventilation units, each carbon neutral in manufacture[5], across teaching spaces. These units help reduce heat loss by an estimated 47,800 kWh per year, avoiding approximately 10.3 tonnes of CO₂e annually[6]. A further 5,100 kWh/year is saved through CO₂ sensor-controlled demand ventilation, avoiding an additional 2.2 tonnes of CO₂e[7].
These may not be headline-grabbing numbers, but they represent deliberate, cumulative design decisions that enhance the building’s efficiency without compromising its retained structure.
Reuse and Responsibility
While the structural choices drove the bulk of the carbon saving, the MEP design ensured those savings weren’t undermined. In refurbishment, the greatest contribution is often knowing where not to intervene.
Footnotes
Estimates based on lifecycle modelling using RICS WLC methodology and structural engineer’s baseline material schedules.
UK BEIS 2023 emissions factor of 4.66 tonnes CO₂e/year per average petrol car.
Based on an average sequestration rate of 21 kg CO₂/year per mature broadleaf tree (Forestry Commission UK, 2022).
Assuming 250 kWh/m²/year generation for roof-mounted PV in Isle of Man climate.
Manufacturer declaration; embodied carbon offset at point of sale (EPD available).
Based on IOM gas carbon factor of 0.216 kg CO₂e/kWh.
Based on IOM electricity carbon factor of 0.430 kg CO₂e/kWh.
Project Info:
Architect: Wilson Mason Architects
Structural: BB Consulting Engineers
Contractor: Excel Group
Client: King William’s College