1.Can you tell us what the International Passive House Association (iPHA) does?


The Passive House Standard has enjoyed increasing interest over the last decade from both construction professionals and their clients, often in places quite distant from the Standard’s Central European birthplace.  In order to connect these stakeholders and support both the promotion and the advancement of Passive House globally, the Passive House Institute, under the direction of the Standard’s creator Dr. Wolfgang Feist, founded the International Passive House Association (iPHA). 


iPHA is a membership-based organisation charged with communicating on Passive House internationally. It works to make the Passive House Institute’s vast research and guidance on Passive House accessible and is, at the same time, in the position to pool the experience of some 2500 members from over 40 countries with the aim to further the Passive House Standard on a global level and drive its uptake. The overarching objective of these activities: to curb energy use in the building sector through energy efficiency and better quality construction.


Concretely, iPHA hosts and maintains Passipedia (www.passipedia.org), a growing, wiki-based compendium of Passive House research. The organisation communicates on the Standard through its web presence, as part of various international Passive House cooperation projects such as PassREg (www.passreg.eu) and EuroPHit (www.europhit.eu), with events such as the Passive House Conference (www.passivehouseconference.org) and the International Passive House Days, and via informative publications such as Active for more comfort, the Passive House brochure. In its networking activities, iPHA works closely with its currently 19 member-based partner organisations worldwide, known as Affiliates, in serving the common membership base as well as reaching out to the general public.


2.What is considered to be a ‘Passive House’ and what are the criteria?

A Passive House building is like any other building, just built better. The quality and attention to detail required by the Standard results in longer-lived, healthier, and more comfortable buildings that of course use a minimal amount of energy for heating and cooling. 


Passive Houses adhere to a set of transparent energy performance criteria and are planned with the Passive House Planning Package, an extremely accurate excel-based energy balancing tool that verifies whether these criteria have been met. The Passive House criteria are as follows:




Space Heating Demand

not to exceed 15kWh annually OR 10W (peak demand) per square metre of usable living space

Space Cooling Demand

roughly matches the heat demand with an additional, climate-dependent allowance for dehumidification

Primary Energy Demand

not to exceed 120kWh annually for all domestic applications (heating, cooling, hot water and domestic electricity) per square meter of usable living space


maximum of 0.6 air changes per hour at 50 Pascals pressure (as verified with an onsite pressure test in both pressurised and depressurised states)

Thermal comfort

must be met for all living areas year-round with not more than 10% of the hours in any given year over 25°C





Passive House buildings may further undergo certification by a Passive House Institute accredited building certifier as an extra quality assurance measure. Logically, Passive House often also forms the energetic basis for other sustainability certifications such as LEED or BREEAM.


Unlike many other certification schemes though, it is important to note that the Passive House criteria only set the energetic bar – they do not dictate how that bar is to be reached. With Passive House, architects are free to be creative with their designs and are even required to adapt their plans to the local climate and needs in order to meet the Standard (you’ll need less insulation, for example, in Spain than in Sweden). Indeed, there is no ‘typical’ Passive House building. 


3.How many Passive House office buildings are there compared to Passive House homes and how is this developing? 


When Passive House gets off the ground in a region, the majority of buildings constructed to the standard are typically single-family homes, whether in the form of terraced houses or detached houses. From this starting point, apartment buildings are the next logical step and then architects start to venture into schools as well as commercial and office buildings. Clinics, hospitals, laboratories, supermarkets and other special use buildings come later. Interestingly enough though, it is often easier to reach the Standard with these large buildings given their favourable volume to surface area ratios (they have less surface through which heat can pass) – visible in Sweden, for example, where the majority of Certified Passive Houses are schools. 


No one is required to report having built a Passive House, but current conservative estimates point to some 50,000 Passive House units worldwide (with a unit being described as one apartment or a floor area of 100m2). Of these, about 8,850 are certified. Looking at the certified buildings, 4,650 units, or just over half, are residential buildings ranging from small single family homes to large apartment complexes whereas about 4,200 units are considered non-residential. This ratio then, is likely reflective of Passive House buildings in general – there may be more individual residential buildings built to Passive House than non-residential, but in terms of area, non-residential buildings are catching up. 


Especially as local authorities discover the Standard for themselves and the savings it can bring, more and more non-residential buildings are being planned. This trend is sure to continue into the future, spurred also by the upcoming EU Building Energy Directive calling for Nearly Zero Energy Buildings (Passive Houses) by 2020.


4.What is the organisation’s main goal for the future? 


iPHA’s main goal is to bring Passive House as the basis for sustainable building solutions to as many people around the world as possible in an effort to curb climate change.


5.Do you think the economy affects Passive House projects?


The economy certainly affects projects, although the effects are more complex than one might expect. During times of economic hardship, as is the case throughout the building industry, people may not have the money to finish projects. The difference with Passive House, however, is that such difficult times often result in people and local authorities gravitating even more towards this energy efficient standard, attracted by the reliably low running costs such buildings offer. Banks, too, are beginning to see Passive House as a better investment during hard times, as occupants with extremely low energy bills have more money left over to repay loans. Finally, when the economy has slumped, designers young and old often seize the opportunity to reorient themselves, engaging in Passive House training or to get involved in Passive House associations. This is something we have seen in both Spain and Greece, for example, where Passive House networks are thriving.