Such is the importance of ventilation, it’s only right and proper that the efficacy of innovative mechanical solutions such as heat recovery ventilation and demand controlled mechanical extract ventilation is established
based on robust, comprehensive evidence. But how does natural ventilation fare when subjected to the same degree of scrutiny, and can it work in low energy buildings?

Tina Holt had experience advising homeowners on energy efficiency, so when she wanted a low energy home, buying a run-down 1950s dwelling and aiming to turn it passive was an obvious step. She tells her own story below.

Most energy upgrades to historic homes in architectural conservation zones take a fairly gentle approach to insulation and airtightness — this one did the exact opposite.

Some buildings are beyond saving, such as a south Dublin cottage which had to be knocked to deliver the first phase of a sleek new low energy home.

This upgrade and extension to a rural home in County Cork cut its energy use by almost 90%, bringing it to the cusp of an A1 Building Energy Rating.

This certified passive house on the west coast of Scotland might look like a traditional hayshed, but it’s certainly more energy efficient than one.

In the absence of strong energy requirements under building regulations, much of the UK’s new build innovation has been driven by the Code for Sustainable Homes. Amid growing concern that the code’s attention to energy efficiency falls some way short of passive house, monitoring results from one social housing scheme offer a rare opportunity for direct comparison.

Exploding the myth that passive house means unfamiliar construction methods and considerable expense, one Cork-based builder has gone passive using wide cavity wall construction – for a competitive cost of €100 per sq ft.

This issue’s selection of international buildings include Spain’s first passive houses built from straw bales, an architecturally striking energy-plus office building in Denmark, and an Austrian family home that marries ecology, comfort and delightful design.