PASSIVHAUS Certified Efficient Homes

DOMUS DP Real Estate

Have you ever heard of the "Passivhaus"? In this type of housing the protagonist is not the interiordesign, what counts above all is the exterior design, being the first design factor and the most important, the climate.

In short, passiv houses have been a revolution in the field of construction because they improve efficiency and reduce energy consumption without sacrificing quality, maximum comforts and at an affordable price.
But do you want to know what a Passivhaus is and how it differs from a "conventional" house?


- The Passivhaus are homes designed to maintain optimal temperature and humidity conditions inside, in a natural way, with the aim of minimizing the use of air conditioning systems such as heating, air conditioning, etc.
In fact, their name (passive houses) is due to the fact that they require very little energy to maintain a pleasant temperature, achieving energy savings of between 70% and 90% compared to conventional constructions.
And although until now this construction model that began to develop in Germany in the 70s was applied only to residential areas (especially to villas, independent houses or single-family homes), it can now be used to design hotels, offices, government buildings and even educational centers.


- The Passivhaus standard is a way of constructing Nearly Zero Consumption Buildings (ECCN). This system establishes the construction methods and systems that a home must comply with to be officially certified as "passive".

- All passive constructions in the world have to meet these requirements, issued by the Passivhaus Institut:
• Annual heating/cooling demand of less than 15 kWh/m² or a thermal load of less than 10 kW/m².
• Total energy demand (lighting, domestic hot water, household appliances, etc.) less than 120 kWh/m².
• High sealing interest (to avoid energy leaks), with a result in the Blower Door Test <0.6 renewals/h).
- To achieve Passivhaus certification it is not only necessary to use sustainable and high-quality materials: planning and design are also essential.

- The main characteristics of passive houses are:
• Isolation. The control of thermal losses and gains through enclosures, roofs and slabs is essential. For this reason, in passive houses it is common to put a layer of continuous and uninterrupted insulation. For the facades, a sate system (Exterior Thermal Insulation Solution) of high performance is chosen. For the covers, extruded polystyrene insulation plates are used.
• Breakage of thermal bridges. Choosing the right materials in the design of the house is basic to reduce thermal bridges. These can occur in joints, changes in geometry or the encounter of materials, generating heat losses, condensation and mold that can deteriorate structures.
• Quality windows. The carpentry (doors, windows, enclosures, etc.) have the double function of reducing the thermal flow to the maximum and allowing solar gains in winter, and are one of the weakest elements of the housing envelope. The Passivhaus standard uses glass with double insulating chamber to reduce energy losses inside. Taking care of the assembly of doors and windows is also essential to prevent sealing failures.
• Tightness/Tightness. In a Passivhaus dwelling, energy losses that reach 30-40% of the overall energy consumption of the house are not allowed. For this reason, passive dwellings are designed "watertight", that is, airtight, in order to avoid drafts. In addition, the drawers of the roller blinds must be located outside the envelope and have electric motorization.
• Ventilation and heat recovery system. For the correct renewal of the air, the Passivhaus incorporate a mechanical system that supplies quality air (filtered and free of mites, dust, etc.) to the rooms, with impulsion ducts in dining rooms, rooms and bedrooms, and with extractors in kitchen and bathrooms. This system recovers up to 85-90% of the heat expelled to temper the house, and allows to maintain the ambient humidity in optimal conditions (between 40-60%).


- Living in a Passivhaus has many advantages. To begin with, this type of houses optimize and take advantage of all the excess heat, increasing the comfort of the house and reducing energy consumption by up to 90%.

- Passive houses are also an example of sustainability both economically and environmentally, because they emit minimal waste. In addition, the maintenance of a stable and constant temperature, without drafts, eliminates humidity and bad odors, contributing to the well-being of the inhabitants of the house.

- On the other hand, the intelligent renewal of the air of passivhaus houses helps to avoid infections in the respiratory tract, allergies or asthma derived from poor ventilation in the house.

- The Passivhaus require proper planning and design to meet the standards of this construction model. To certify and verify its suitability, it is necessary to contact a Passivhaus Technician who verifies compliance with all the requirements established in each phase of the project.