As our climate continues to warm, the issue of overheating in UK homes is no longer a theoretical concern – it’s a pressing reality impacting health, comfort, and the overall liveability of our properties. We were delighted to join the Chartered Institute of Housing (CIH) for their latest podcast, where our Managing Director, Jack Allen, sat down with CIH policy manager Matthew Scott.
This essential conversation explored the critical technical and practical aspects of overheating, highlighting its significant and often overlooked impact on tenant wellbeing and building performance. In this blog, we’ll unpack the key insights from their discussion and share how we can help you navigate this complex challenge.
Listen to the Full Discussion:
You can listen to the complete CIH podcast episode featuring Jack Allen here:
Listen on YouTube | Listen on Spotify
Why Overheating is a Growing Crisis: Key Takeaways
The podcast illuminated several crucial aspects of the overheating problem, moving beyond simple temperature readings to reveal a complex interplay of factors:
The Alarming Human Cost
The stark reality of extreme heat was highlighted, with Matthew and Jack citing the 4,500 excess deaths recorded during the 2022 heatwave alone. This isn’t just a statistic; it represents profound human suffering, impacting vulnerable individuals like the elderly, children, and those with existing health conditions. Beyond fatalities, overheating severely affects mental health, sleep, and overall productivity, making homes uncomfortable and unhealthy living spaces.
Identifying Building Vulnerabilities
Certain building types are inherently more susceptible to overheating. The discussion pinpointed:
- High-rise flats: Often exposed to more solar gain due to less shading, and prone to the “stack effect” where warm air rises, making upper floors significantly hotter.
- Single-aspect properties: Lacking the cross-ventilation needed to purge hot air.
- Extensive glazing: While offering views, large south or west-facing windows can become heat traps without adequate shading.
- Urban Heat Islands: Cities, with their dense concrete and tarmac, can be several degrees warmer than surrounding rural areas, intensifying the heat within urban dwellings.
Our ‘Whole Life Cycle’ Approach
At Building Energy Experts, our guiding principle is that energy performance needs to be considered at each and every phase of a building’s life. The podcast underscored this philosophy, from initial planning (asking if a building is even necessary, or if repurposing an existing structure is more sustainable) to material choices (e.g. timber vs. carbon-intensive concrete), operational performance, and eventual end-of-life recycling. Climate change demands a holistic view that moves beyond isolated design decisions.
Navigating Part O: Strengths and Limitations
Part O of the Building Regulations is a welcome step, setting technical definitions for overheating (e.g., not exceeding 28 degrees for more than 1% of occupied hours). However, the podcast also discussed its limitations:
- Future Climate Resilience: Part O‘s long-term effectiveness against increasingly extreme weather events needs ongoing review.
- Planning System Challenges: Achieving optimal solutions like external shading can be hindered by lengthy planning processes or aesthetic restrictions in conservation areas, often pushing developers towards less sustainable, active cooling solutions like air conditioning.
Practical Solutions for Mitigation
The conversation provided a wealth of practical strategies for both existing and new properties:
- For Existing Homes: Engage with residents through questionnaires, implement blue-green infrastructure (trees, green roofs, green walls) for microclimatic cooling, install continuous mechanical ventilation systems (which also tackle condensation and mould), consider external shading devices (shutters, brise soleil), and educate tenants on smart use of internal blinds.
- For New Builds: Prioritise thoughtful orientation, design for effective cross-ventilation, manage glazing ratios, and integrate advanced ventilation systems like Mechanical Ventilation with Heat Recovery (MVHR) from the outset.
The PAS 2035 Opportunity
Retrofitting properties presents a significant chance to address overheating. The new PAS 2035 requirements, particularly the need for ventilation assessments, are crucial. When recladding or insulating, there’s a prime opportunity to integrate passive cooling measures like external shading, a step that is often overlooked but vital for long-term comfort.
Embracing the Passivhaus Standard
The podcast concluded with an exploration of Passivhaus, a rigorous building standard developed in Germany. Jack explained how Passivhaus homes require minimal heating due to their exceptional airtightness and highly insulated fabric. Intelligent design, including strategic shading for summer sun, ensures they also stay cool. Coupled with MVHR systems that recover heat in winter and purge it in summer, Passivhaus offers a powerful solution for comfortable, healthy, and near-zero energy homes, embodying a truly holistic approach to building performance.
Master Part O: Practical Training for Overheating Compliance
The insights shared in this podcast underscore the growing importance of proactive overheating mitigation. To help professionals like you gain a comprehensive understanding of current regulations and practical solutions, we offer a specialised Part O Overheating CPD session for housing developers, architects and housing professionals.
This session delves into:
- The technical requirements of Part O and compliance pathways.
- Strategies for designing out overheating in various building types.
- Practical application in both new build and retrofit projects.
- How to integrate overheating considerations holistically with other key building regulations (e.g., Part L for energy efficiency and Part F for ventilation).
Get in Touch
Overheating is a multifaceted challenge, but with the right knowledge and proactive measures, we can create resilient, comfortable, and healthy living spaces for the future. At Building Energy Experts, we are committed to supporting the built environment sector in navigating these complexities.
Contact us today to discuss your specific project needs or if you have any questions about overheating assessments and solutions.
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