As awareness of the urgency of the climate crisis grows, efforts to kickstart en masse deep energy efficiency interventions are gathering apace. But poorly conceived low energy building efforts can lead to unintended consequences including overheating – a risk that’s bound to grow as the world warms up. Phi Architecture co-founder Claire Jamieson details the risks and offers some solutions on how to create low energy buildings that are comfortable in summer and winter.

Heat recovery ventilation is an invaluable way to maintain indoor air quality in low energy buildings and minimise the loss of precious heat, but there are several issues to address to ensure optimal performance. Ventilation expert Ian Mawditt, a technical advisor on Part F of England’s building regulations, has decades of experience in field investigations of indoor air quality and ventilation effectiveness. His guide, which focuses on centralised or ducted whole house heat recovery systems, is essential reading to anyone considering such a system.

Once poorly understood by the mainstream building industry, airtightness is now increasingly seen as one of the most crucial objectives on any building project. Not only is it vital for energy efficiency, it’s also key for thermal comfort and for protecting a building’s structure from dampness and mould. In this comprehensive guide to airtightness, we look at why it’s so important, how exactly it’s measured, and most importantly, how to achieve it on site.

As demand for super-insulated and airtight building structures grows, insulating concrete formwork (ICF) is rapidly gaining popularity as a method of construction. But what exactly is ICF, what are its key advantages, and why is it so well suited to passive house and low energy construction?

As electricity supply from renewable sources continues to grow, and electricity grids gradually decarbonise as dirtier fossil fuels are phased out, heating homes with electrical technologies like heat pumps starts to make more sense. And in the mild, temperate climate of Britain and Ireland, air source heat pumps are particularly suitable — especially as new build standards of energy efficiency continue to tighten, meaning new homes need less and less energy to achieve comfortable indoor temperatures. But how do air source heat pumps work, what types are there, and how much do they cost to run? Our in-depth guide attempts to answer the key questions.

Building physics take no prisoners. Anyone designing, constructing or upgrading the thermal envelope of a building to modern energy performance levels is duty bound to understand and minimise thermal bridging, or suffer the consequences. One-man thermal bridging encyclopaedia Andrew Lundberg of Passivate, who teaches thermal bridging analysis at Dublin Institute of Technology, gives some practical advice on why and how to tackle thermal bridging head on, and describes some of the leading innovations in thermally broken components.

In the first in a new series of technical articles on some of the key technologies in sustainable building, John Hearne makes the case for wrapping buildings in an external insulation layer, and describes some of the main issues to watch out for.