Passive houses and the commitment to energy efficiency

There is a type of home that does not require heating in winter or air conditioning in summer. Have you heard of them? They are called passive houses and the name already applies to a large number of projects that are committed to energy efficiency as an essential feature of the home from the moment it starts to be built.

To achieve this, experts developing passive house technologies need to focus on three essential features:

• Controlled ventilation systems that ensure effective maintenance of the ideal temperature, with the correct recovery of cold and heat where necessary.
• The materials used in the doors, windows and walls of the house.
• The re-use of traditional household devices that can be used to generate heat.

In these passives houses the temperature is usually about 20ºC, although it can vary depending on the location and the geography of the surrounding area. However, this temperature is maintained without the need for electric or gas devices that have been purchased in order to acclimatise the building.

Because no energy is used to maintain the temperature, it can focus on the other day-to-day tasks to be done in the home. This is how passive homes become real models of energy efficiency that inspire other experts to create materials that are of better thermal quality and are more efficient.

From the passive house of the 1980s to current sustainable design.

The passive house (also called passivhaus in some specialised media) is not a recent concept. In the 1980s they started building the first models of what we understand today as a passive house in Germany, although the elements have undergone considerable development since the origin of the movement.

At that time, they sought to use materials of the highest energy quality but their decisions were more linked to the orientation of the house and the positioning of the doors and windows. Nowadays, design principles also taken into account when making the following decisions:

• The form that the building will take and its relationship with the surrounding area.
• The internal distribution of the rooms.
• The use of spaces between rooms designed to block drafts of air.
• The movement of the sun throughout the year and the shadows it casts behind suitable elements like pergolas, roof extensions and other architectural features.
• The thermal mass of the building to take advantage of sunlight and maintain the most suitable temperature.

These constructions are classified within the framework of bioclimatic architecture, which together with energy design, aims to insulate the house to maintain the temperature. This type of housing is usually combined with other innovative elements based on energy design, as in the case of Marjan van Aubel and his energy generators for the home.

How to verify if you have a passive house

A passive house involves a series of requirements and to ensure due compliance, there is an organisation that verifies whether or not a house meets a series of necessary characteristics.

The International Passive House Association (iPHA) is responsible for this and the technical requirements they verify are the energy demand corresponding to ventilation and the use of household devices, as well as airtightness and thermal sensation.

Passive houses have a twofold objective: Firstly lower energy consumption with a view to economic savings on bills, but it is also an architectural style that is the result of responsibility and respect for the environment.

It is not easy to apply the principles of the passive house in all buildings, since the space is usually conditioned and not all of its principles can be put into practice. However, it is a growing trend that is already beginning to influence other designs that are not so traditionally focussed on sustainability.