The Buchan School: A Practical Case for the Circular Economy

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.

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Footnotes

1. Estimates based on lifecycle modelling using RICS WLC methodology and structural engineer’s baseline material schedules.

2. UK BEIS 2023 emissions factor of 4.66 tonnes CO₂e/year per average petrol car.

3. Based on an average sequestration rate of 21 kg CO₂/year per mature broadleaf tree (Forestry Commission UK, 2022).

4. Assuming 250 kWh/m²/year generation for roof-mounted PV in Isle of Man climate.

5. Manufacturer declaration; embodied carbon offset at point of sale (EPD available).

6. Based on IOM gas carbon factor of 0.216 kg CO₂e/kWh.

7. Based on IOM electricity carbon factor of 0.430 kg CO₂e/kWh.

Project Info:

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Architect: Wilson Mason Architects

Structural: BB Consulting Engineers

PQS: Bell Burton Associates

Contractor: Excel Group

Client: King William’s College

Hybrid Ventilation and BB101 Compliance: Driving Energy Savings and Healthier Classrooms

Ensuring a healthy indoor environment in schools is paramount, particularly given the requirements of BB101 (Guidelines on Ventilation, Thermal Comfort and Indoor Air Quality in Schools). At March Consultants Limited, we believe meeting these guidelines shouldn’t compromise sustainability or occupant health. By adopting hybrid ventilation strategies, educational facilities not only reduce energy consumption but also limit the spread of airborne illnesses—critical in safeguarding both staff and students.

Why BB101 and Good Ventilation Matter

• Indoor Air Quality
  BB101 mandates minimum fresh-air provision and sets thresholds for parameters like temperature and CO₂. Consistent airflow and effective filtration can also dilute the concentration of airborne pathogens indoors.

• Thermal Comfort
  Maintaining consistent temperatures helps reduce discomfort and distractions, further supporting a stable learning environment.

• Airborne Illness Mitigation
  Multiple studies, including those published in The Lancet and The Lancet Respiratory Medicine, have shown that improved ventilation significantly reduces the risk of respiratory infections by lowering the concentration of aerosolised particles. The World Health Organization (WHO) and ASHRAE likewise emphasise ventilation as a key factor in reducing airborne disease transmission.

Ventilation Strategies in Schools

• Natural Ventilation

  • Benefits: Uses zero fan energy, straightforward when weather conditions are mild.

  • Challenges: Significant heat loss in colder months, risk of under-ventilation if users forget to open windows.

• Mechanical Ventilation with Heat Recovery (MVHR)

  • Benefits: Recovers heat from exhaust air, reducing winter heating loads.

  • Challenges: Requires continuous fan energy, potentially raising electricity costs and noise levels.

• Hybrid Ventilation

  • Benefits: Combines passive (natural) and mechanical approaches; fans kick in only when sensors detect high CO₂ or low temperatures.

  • Result: Lower overall energy use than full MVHR, reduced heat losses compared to full natural ventilation, and better indoor air quality—helping mitigate virus transmission by maintaining sufficient fresh air exchange.

How Hybrid Ventilation Outperforms

By blending natural ventilation during mild conditions with selective mechanical assistance in high‑demand periods (e.g. winter mornings, high occupancy), hybrid systems often offer:

• Reduced Fan Power: Fans run on-demand rather than continuously.

• Moderate Heat Recovery: Recovers a portion of the exhaust air’s heat, cutting winter heating bills.

• CO₂ and Pathogen Control: Constant monitoring ensures classroom air remains fresh, diluting airborne microbes.

Such demand-driven ventilation aligns with BB101 thresholds while also adhering to WHO and ASHRAE guidance on maintaining healthy airflows to reduce infection risks. In essence, a well-tuned hybrid solution can significantly lower energy costs and improve occupant health in comparison to standalone natural or fully mechanical strategies.

MCL’s Approach to Healthy, Efficient Schools

At March Consultants Limited, we design and commission hybrid ventilation solutions in both new builds and refurbishments, ensuring they meet BB101 standards. Through meticulous coordination with architects and structural engineers, we integrate:

• Demand-Controlled Ventilation: Sensors modulate airflow based on real-time CO₂ and temperature readings, maintaining air quality and mitigating the spread of airborne illnesses.

• Efficient Heat Recovery: Systems that balance heat retention with minimal fan run‑times.

• Robust Controls: Centralised, user-friendly controls let facility managers monitor and adjust ventilation settings to accommodate changing occupancy levels.

This holistic approach helps schools provide comfortable, healthier, and energy-efficient environments—demonstrating that compliance with BB101 and controlling airborne infections need not inflate utility bills.

Ready to Learn More?

If you’re looking to enhance air quality in your educational facility while keeping energy costs and infection risks in check, reach out to us at March Consultants Limited. Our MEP engineering team can guide you through the nuances of hybrid ventilation, ensuring a well-commissioned system that ticks all the boxes: BB101 compliance, energy efficiency, and occupant wellbeing.

For further insights, follow March on LinkedIn. Let’s collaborate to create modern, resilient spaces where students and staff can thrive safely and sustainably.

Related Projects:

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The Buchan School Refurbishment

Henry Bloom Noble Primary School

Ballakermeen High School Post-16 Extension

Unlock Energy Savings with the Isle of Man Government’s Business Energy Saving Scheme

The Business Energy Saving Scheme (BESS), run by the Isle of Man Government's Department for Enterprise, offers businesses the opportunity to make energy efficiency upgrades through interest-free loans of up to £100,000. A key requirement for accessing these loans is completing an energy audit, which helps identify the most effective measures for reducing energy consumption and costs. Additionally, the BESS covers 75% of the cost of these energy audits, making it easier for businesses to assess their energy usage and discover where savings can be made.

Supporting Your Energy Efficiency Goals

At March Consultants Limited (MCL) we offer the comprehensive energy audits required to qualify for the BESS. With over 20 years of experience and deep technical expertise, we deliver clear, actionable recommendations to help businesses reduce costs and improve energy efficiency. Our audits focus on practical solutions tailored to your energy needs, ensuring long-term benefits.

How the BESS Can Transform Your Energy Profile

Let’s consider a hypothetical 500m² office building and how it can improve its energy efficiency using solutions that fit within the £100,000 loan limit.

Step 1: The Energy Audit

The process begins with an energy audit, where we meet with stakeholders to discuss their goals and aspirations for improving energy efficiency. During this stage, we gather data to build an accurate energy profile of the building. If this data isn't available, we digitally simulate energy usage to ensure we fully understand the building’s consumption patterns.

One of the key benefits of the BESS is that it covers 75% of the energy audit fee, making it easier for businesses to take the first step toward identifying significant energy savings. The audit provides a detailed view of where and how energy is consumed, forming the foundation for all future decisions.

Step 2: Tailored Energy Strategy & Outline Specification

Once the audit is complete, we develop a tailored energy strategy that focuses on the most impactful energy-saving measures for the building. This strategy includes a detailed outline of the proposed upgrades as well as a budget estimation for implementation.

For our hypothetical office building, the data shows that space and water heating account for more than 50% of total energy consumption. Based on this, the strategy recommends replacing the existing 80% efficient gas-fired heating system with a 350% efficient air source heat pump (ASHP). A high-temperature ASHP is specified to reduce the need for costly upgrades to the building’s existing heating emitters. Additionally, the ASHP will be fitted with coastal protection to ensure long-term durability in the Isle of Man’s coastal environment.

The energy strategy also recommends pairing the ASHP with a solar PV array, expected to generate approximately 8,500 kWh per year. The combined estimated cost for these systems is £65,000, which will be included in the strategy document as part of the financial planning for the project.

Step 3: Application to the BESS

Once the audit and recommendations are complete, our client prepares the application to the Business Energy Saving Scheme (BESS). MCL supports this process by providing the detailed audit report along with the outline specification for the proposed energy-saving measures. We assist the client throughout the application process, ensuring they have all the necessary documentation to successfully apply for BESS funding.

Step 4: Implementation and Realising the Benefits

Once funding is secured and installation is completed by certified contractors, businesses can expect immediate improvements in energy efficiency.

By replacing the gas-fired heating system, energy consumption for space and water heating can be reduced by up to 60%. Additionally, by using solar energy for water heating and supplementing space heating, reliance on grid electricity is further reduced.

The overall payback period for these measures is estimated to be within 10 years, which is well within the expected lifespan of the systems if they are properly maintained. This ensures that the building will benefit from reduced operational costs and greater energy efficiency for many years to come.

Additional Energy-Saving Opportunities

In addition to the ASHP and solar PV system, other potential energy-saving measures that could be implemented include:

• Ultra-efficient LED lighting and advanced controls to reduce electricity consumption for lighting.

• Building system automation to optimise the control of heating, cooling, and lighting systems.

• Waste heat recovery systems to capture and reuse excess heat.

• Solar glazing to improve thermal performance and reduce cooling loads.

• Domestic hot water heat pumps to further lower energy consumption for water heating.

Work with March Consultants Limited

At March Consultants Limited, our approach to energy efficiency goes beyond standard audits. With our deep expertise in mechanical, electrical, and plumbing (MEP) systems design, we ensure that the energy-saving measures we recommend are not only effective but also fully aligned with the building’s technical requirements. Our solutions are designed to integrate seamlessly with existing systems, optimising performance and maximising long-term savings.

From the initial energy audit to clear recommendations and ongoing support, we help you make the most of the Business Energy Saving Scheme (BESS), delivering practical, technically sound solutions tailored to your building’s needs.

If you’re ready to explore how the BESS can benefit your organisation, contact us to discuss how we can support your energy efficiency goals.

Overcoming Overheating Risks in Heavily Glazed Buildings: A TM59 Case Study at Westmoreland Road

At March Consultants Limited (MCL), we are committed to pioneering sustainable building solutions that not only meet but exceed current performance standards. Our latest project, the refurbishment of the historic former nurses' home on Westmoreland Road, is a prime example of this.

An architectural highlight of the project is the top storey, which is distinctively encased in curtain walling. This feature, while aesthetically pleasing, presented unique challenges due to the potential for high solar heat gain, which could lead to significant overheating, particularly in the warmer months, yes, even on the Isle of Man.

Recent evidence underscores that overheating risk needs to be taken seriously, particularly in the residential sector. Many new or refurbished homes face overheating risks due to factors like high proportions of glazing, inadequate natural ventilation, or mechanical ventilation systems failing to deliver the intended air change rates. The health and well-being impacts of overheating can be profound, resulting in issues like stress, anxiety, sleep deprivation, and even premature deaths during heatwaves. According to the UKHSA, mortality rates from overheating, without adaptation, could rise to 10,000 per year by the 2050s.

To effectively address these challenges, MCL employed TM59: Design methodology for the assessment of overheating risk in homes, a rigorous standard developed by the Chartered Institute of Building Services Engineers (CIBSE).

TM59 is particularly valuable for its robust approach to evaluating these risks by considering a range of factors such as geographic location, climate, building orientation, and a standardised set of internal conditions. It particularly stands out for its compliance criteria, including:

1. Criterion A: For living rooms, kitchens, and bedrooms; sets a limit of 3% on the number of occupied hours that the operative temperature can exceed the threshold comfort temperature, Tmax, by 1K or more during a typical non-heating season – 1 May to 30 September. Tmax is a function of the outdoor running-mean temperature.

2. Criterion B: For bedrooms only; to guarantee comfort during the sleeping hours the operative temperature in the bedroom from 10 pm to 7 am shall not exceed 26 °C for more than 1% of annual hours.

As anticipated, the first iteration of the TM59 model showed significant overheating in the living spaces and bedrooms. This initial finding underscored the critical need for a design rethink to ensure thermal comfort.

In response, our team engaged in a focused collaboration with the architect, cost consultant, and window manufacturer to develop a series of targeted design interventions. We chose parallel opening windows which offer a significantly larger openable area compared to other restricted window openings, e.g. top-hung. Carefully positioned to maximise crossflow ventilation, these windows greatly improved the efficiency of our passive cooling strategy. Additionally, we selected high-performance glass engineered to reduce solar gain while maintaining excellent light transmission.

These targeted measures successfully met the rigorous standards of TM59 criteria A & B, confirming our ability to maintain thermal comfort on the top floor without relying on energy-intensive mechanical cooling systems.

The U-value of the glazing was also carefully selected, again, in partnership with with the design team. We undertook a detailed cost-benefit analysis to evaluate the balance between installation costs and anticipated energy savings. This strategic decision ensures that our solutions are not only effective in reducing energy consumption but also economically viable, providing long-term value to our clients.

By combining innovative design strategies with rigorous engineering analysis, MCL continues to lead in the field of MEP engineering, pushing the boundaries of what is possible in the design of contemporary and architecturally striking structures. Our expertise allows architects to embrace ambitious designs, without compromising on environmental sustainability or occupant comfort.

For more insights into our projects or to discuss your own needs for innovative MEP solutions, please call 01624 616300.

Project Info:

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Title: Former Nurses' Home

Client: Manx Development Corporation

Architect: Ellis Williams Architects

Structural Engineer: BB Consulting Engineers

Quantity Surveyor: Bell Burton Associates