Adaptive reuse projects are gaining popularity across the UK as people start to recognise the benefits they offer. This is certainly the case in London, where we’ve seen how major developments like Battersea Power Station can be transformed by adapting the existing structure. 

While adaptive reuse differs from standard retrofit practices through the repurposing of buildings for new functions, as opposed to simply optimising their existing performance, both approaches provide sustainable alternatives to demolition, as well as opportunities for developers to address building performance and sustainability demands. One of the ways this can be done is through EnerPHit and Passivhaus retrofit standards.

London's building stock presents significant challenges for adaptive reuse projects. Around 15% of homes in England were built pre-1900, long before the concept of energy efficiency was formalised or any modern standards were introduced. These buildings were simply not designed with thermal performance or controlled ventilation in mind.

The result is a large number of buildings that perform poorly by modern standards. They typically have inadequate insulation, are draughty, and consume significant amounts of energy for heating and cooling. Some of the most common issues we encounter in retrofit projects include moisture problems that can damage the building fabric, as well as inadequate ventilation, leading to poor indoor air quality. Retrofitting these buildings with modern HVAC systems has additional challenges, such as working with limited space and structural limitations. These problems require comprehensive solutions in order to be adapted to meet today's sustainability demands.

However, the EnerPHit standard offers a practical solution to these challenges. This approach was specifically developed for retrofit applications and can deliver near-Passivhaus levels of energy efficiency without requiring complete reconstruction. It addresses the core issues of thermal bridging, air leakage, and inadequate ventilation through enhanced insulation, airtight construction, and improved ventilation systems. This approach preserves the built environment while often being faster and less expensive than demolition and rebuild.

London’s building stock offers a compelling opportunity for EnerPHit implementation, given the historic and heritage considerations. Unlike new-build Passivhaus projects, EnerPHit retrofits can work within existing structures and conservation restrictions, while still delivering high-performance ventilation.

In adaptive reuse projects, mechanical ventilation with heat recovery (MVHR), a crucial component of EnerPHit, is particularly beneficial. It improves indoor air quality, reduces energy consumption, and can be integrated relatively easily into existing buildings. By recovering heat from outgoing air, MVHR can significantly reduce heating costs and improve overall efficiency.

Purpose-designed systems like Airflow's DUPLEXbase PS range exist to address the ventilation needs of renovated commercial buildings that have become more airtight through improved insulation. In this case, the system provides continuous extraction and supply ventilation, preventing moisture damage and mould growth that can occur when natural air exchange is no longer possible. Even when structural constraints prevent central MVHR installation, heat recovery units offer a practical solution. 

In this case, the system provides continuous extraction and supply ventilation with exceptional thermal efficiency over 90%, preventing moisture damage and mould growth while delivering powerful air flow with low energy consumption. The versatile design allows floor or ceiling-suspended positioning, indoors or outdoors, making it particularly valuable for applications where installing a central MVHR unit would not be practical or where flexible positioning is essential for optimal performance.

By combining the flexibility of EnerPHit standards with innovative ventilation solutions, adaptive reuse projects can deliver the building performance London needs, without compromising heritage.