There was a time when insulating an historic property meant treading lightly on its building fabric. But today, guided by building physics, passive house designers continue to push the boundaries of retrofit by bringing old homes up to modern standards of super-insulation. This project is the third such deep retrofit to an historic London property by Green Tomato Energy.

The general consensus is that it’s not appropriate to upgrade historic buildings to avant garde energy efficiency levels, creating a sense that conservation of the natural and built environments may be mutually exclusive concerns. Not so, argue Arboreal Architecture’s Harry Paticas and passive house engineer Alan Clarke in an updated version of a paper presented at the 2014 International Passive House Conference, about a highly experimental upgrade to a London townhouse that may point to a sustainable solution.

For self-builder James Byrne, building to the passive house standard was just one element of an approach that aimed to drastically reduce the environmental impact of his house — built from a hemp and lime system, it also features solar collectors, rainwater harvesting and natural wastewater treatment.

Despite its stop-start beginnings, this cottage in the west of Ireland delivers a traditional-but-stylish design with close-to-passive performance.

When work began on this low energy, super airtight project in Co Galway it faced a tight budget and a market for passive house products that had yet to mature. But in the end its owner Hugh Whiriskey emerged with a comfortable home with stunningly low annual heating and hot water costs of just over a euro per square meter.

This uncertified passive house on Ireland’s south-west coast makes a striking-yet-sensitive architectural statement.

Architectural technician Phillip Newbold overcame strict planning rules and a tight budget to build his sensitively designed, super low energy home in an area of outstanding natural beauty.

The team behind a series of passive house schools in Wolverhampton have used the lessons learned from in-depth monitoring of the first two buildings to make the third even better — and cheaper to build.

This year’s international Passive House Awards featured 21 projects — out of about 100 entries — across six different categories, with shortlisted projects coming from across Europe plus New Zealand, South Korea, and the United States. In this issue’s international section, we pick four buildings from an exceptional selection.

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.

In spite of having no construction experience Steve O’Rourke decided to make his self-build home a passive house, a feat achieved by a well-considered and collaborative approach.

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.

Passive house is no longer just the preserve of the self-builder. With over 300 passive houses built to date in multi unit-schemes and a thousand more on the way – along with major non-domestic builds – increasing numbers of British & Irish developers are going passive. But how will the sector cope with upscaling, and will the most cost-conscious developers be attracted to the standard?

Hitting the Enerphit standard can be challenging for even the most seasoned passive house specialist, so what chances did Kate and Geoff Ball’s semi-d have when the architect and builder had no passive experience? With a well-planned approach and no end of enthusiasm, they passed with flying colours, as Kate Ball explains.

In spite of a dauntingly complex and crumbling existing building, a detached house in Donnybrook has been modernised to become Ireland’s 2nd certified Enerphit building. 

Passive house is all about using tiny amounts of energy to deliver maximum comfort for those living and working in buildings that meet the standard. So why did Wain Morehead Architects turn to their passive house knowhow when designing a whiskey distillery that won’t have any occupants?

None of the team behind Passive House Plus has the good fortune to live in a passive house – at least not yet – meaning our promotion of passive house comes with more than a hint of “Do as I say, not as I do”. That’s emphatically not the case with certified passive house designer Helena Fitzgerald, who chose to practice what she preaches with her own home, to stunning effect.