- Romain Poulles
From Passive houses to ACTIVE Houses
The public remains sceptical as to the benefits of passive houses that are as of now imposed on them, and often rightly so, says expert Romain Poulles, who calls for a transition to constructing active houses.
In the context of the introduction of the European directive 2010/31/UE on the energy efficiency of buildings (EPBD), Luxembourg is the first EU country to make passive houses obligatory. The Luxembourg construction sector has adopted this regulation without suffering major disruptions. Public authorities are to be congratulated for creating necessary and favourable conditions to facilitate this transition.
It must be noted that the regulation is less accepted by the wider public, consumers and residents, even though the reasons for this disapproval are mostly of subjective in nature. Doesn’t the adjective “passive” suggest inaction, passivity, acquiescence? The public remains sceptical as to the benefits of passive houses that are as of now imposed on them, and often rightly so.
The concept of the passive house is a first step on the way to the house of the future, but it is still greatly insufficient because it only tackles one dimension of sustainable construction. This unilateral focus might cause problems for consumers if the structure is not conscientiously designed and executed. A recurring issue is the poor air quality of passive houses that can have detrimental effects on residents’ health. On top of being inactive, passive houses are thus also mono-orientated.
It is therefore imperative to transition to the next stage of evolution: active houses. If passive houses mainly seek to reduce energy consumption, active houses are based on a more integrated approach.
Some countries define active houses as “dwellings that produce more energy than they consume thanks to the construction methods used.” These houses should be called positive or surplus energy houses. These structures are, however, still of a single focus and require a more systematic and holistic approach.
In modern societies we spend 90% of our time indoors, either at home, at work or for leisure activities. This amount is increased by time spent on public transport, which leaves us with no more than 5% of our time actually spent outdoors.
The past years have seen the advent of passive houses, as well as the accompanying issue of poor air quality inside of them.
By basing our designs on the idea of the active house, we want to promote solutions that allow people to live in comfortable buildings devised with human needs in mind. It is after all important to not forget that the first and foremost function of these building is to provide a safe and pleasant living environment to its inhabitants. These aspects should never be compromised.
The provision of daylight is a key focus of active houses because it is closely linked to residents’ comfort and well-being. Research into the effects of different lighting conditions has revealed that the quality and quantity of daylight we receive does not only affect our vision, but also our sleep cycle, mood, productivity, alertness and long-term health. Optimal thermal conditions are also pivotal to the creation of healthy interiors. Active houses will be designed to provide optimal thermal conditions in summer and winter. It is to be taken into consideration that humans can adapt well to temperature changes and that the body requires different temperatures depending on the type of room being used and the time of day.
On top of daylight and thermal comfort, interior air quality is crucial. Humans inhale 15kg of air every day, and as we spend 90% of our time indoors, we mostly inhale indoor air. That’s why it is important to be very rigorous about indoor air quality, particularly considering the fact that in most passive houses, indoor air quality is worse than outdoor air quality, even in urban areas.
Active houses actively contribute to the health and comfort of occupants’ lives without negatively impacting climate and the environment. The objective is to systematically elaborate designs that only positively affect the environment. We need a framework for the conception and the refurbishment of houses so that they might positively contribute to occupants’ health, safety and well-being while also being energy efficient and kind to the environment.
The evaluation of active houses is based on the interaction of three factors: interior thermal conditions, energy consumption and impact on the environment.
Active houses accomplish an energy balance by using energy very economically. All of the necessary energy comes from renewable power source built into the structure of the house or situated close to it (such as a district energy system or an electricity network.)
Well-being, interior temperature and comfort
Active houses seek to create healthier and more comfortable lives for occupants by assuring generous amounts of daylight and fresh air. The materials used have a neutral effect on living comfort and room temperature.
Active houses interact positively with their environment by being ideally integrated into the local setting, through their targeted use of resources, and their global impact on the environment.
Sustainable buildings should be devised by focusing on their affordability while also keeping in mind the overall cost of the construction (fees, maintenance, refurbishment and eventual dismantlement.) Active houses’ use of different technologies offers opportunities for a balanced design that is at once cost-effective and profitable. Costs can be reduced if developers work together with proprietors and investors from the start to define their ambitions for performance quality. This way, a balance between developers’ expectations and the realities of the projects’ costs can be achieved and unexpected costs can be limited. Ideally, active houses would implement the principles of a circular economy in the future. The next step would then be the creation of houses that fully integrate the ideals of a circular economy and thereby have a positive effect on people, the economy and the environment. We would call them “positive houses.”
It’s time to take action to advance from positive to active houses (AAA).
Romain Poulles is PROgroup managing director, president of the Eco-Innovation Cluster and member of the sustainable development council (CSDD)