While the principles of low energy building apply equally for new build and upgrades, the reality is that htting passive levels becomes much trickier when retrofitting. The Passive House Institute have taken this on board and created a retrofit standard that is ambitious but achievable.

Upgrading and extending a semi-detached house on a tight site in Limerick required ingenuity from architect Patti O’Neill.

A new development at Grange Lough, Rosslare, reveals that passive houses can be made Irish – both in terms of what they’re built with, and how they look.

Architect Eva Murphyova creates a modern and sustainable take on the traditional farm settlement with the addition of a new envelope, timber frame extension and sustainable heat sources

Energy efficiency is about more than just U-values – the building envelope must be airtight and virtually cold bridge free. Construct Ireland visited a single-leaf concrete house nearing completion in Moate which combines an excellent envelope with wind, solar and a range of green measures, with the aim of reducing energy and carbon figures to zero in the home’s BER score.

A sustainable building must address more than energy, carbon or materials, argues Irish born architect Stephen Roe of up-and-coming London architects Roewu – it must respond to its environment. Not only does Roe’s design for the All Weather House achieve that, it boasts green materials, renewable heating and generous insulation too.

Nottingham passive house enters Solar Decathlon

Staggeringly airtight ecological home in Athenry set to meet the Passive House Institute standard

Any building, no matter how cold and draughty, no matter how remote, can be improved to world-class energy performance, as an upgraded and extended Donegal cottage dating back to the 1800s proves.

Nowhere demonstrates the need for a high-performance building envelope quite like a coastal site. John Hearne visited a cutting edge timber frame house overlooking Sligo Bay that was designed to achieve a highly insulated, air-tight and low embodied energy envelope whilst making the most of the spectacular vista.