Sustainable houses, what requirements must they meet?

In ecological architecture, which seeks to minimize the impact of pollution, the concept of sustainable houses has become the common way to refer to all properties that meet some criterion to be considered environmentally responsible. While different labels have emerged to measure how green the homes that meet their requirements are, they all agree on several aspects, although they focus on different systems.

Some of the most well-known standards, such as Passivhaus, emphasize that there should be no type of consumption in the home. Others prefer to opt for the use of natural and non-polluting elements. Some systems look at everything more globally in urban developments and large buildings, while others focus on homes.

The location where the sustainable houses will be installed also influences the requirements. In Spain, for example, it will not be the same to implement the label of Passivhaus passive houses in an inland mountainous area than on the Mediterranean coast. In this specific case, the passive houses that meet these requirements are designed for the cold northern Europe. In the interior of our country, the regulations can adapt very well, but in very warm coastal areas, it will be more difficult to lower temperatures in summer.

The famous architect Luis de Garrido, very focused on sustainable architecture, sought to harmonize what must be represented by environmentally friendly houses. And he did so by adapting what, in the 1980s, the UN announced to change the way buildings had been conceived until then: "Sustainable development must be one that meets the needs of the present without compromising the ability of future generations to meet their own needs." The Spanish architect centered it on current sustainable houses with the following statement:

"True sustainable architecture is that which satisfies the needs of its occupants, at any time and place, without endangering the well-being and development of future generations." And he added that, for this, it is necessary that the houses built under this idea must follow these guidelines:

• Architectural strategies to optimize resources and materials.
• Minimize energy consumption.
• Promote renewable energy.
• Minimize waste and emissions.
• Minimize maintenance, functionality, and price of buildings.
• Improve the quality of life of its occupants.

With their advantages and disadvantages, all the labels that bet on building sustainable houses meet quite a few of these parameters, to a greater or lesser extent, if not all.

What classification of sustainable houses do we have?

There are various labels and certifications to determine that a house is sustainable, each with its differences and similarities.

First of all, it should be noted that, from this year, in Spain there is an obligation for all public buildings to comply with the European directive to only construct Nearly Zero Energy Buildings. In two years, this obligation will extend to private construction, which will mean a giant leap in sustainable construction.

Among the different labels of sustainable houses, the following stand out:

• Passivhaus Passive Houses. They are the most well-known model, the standard originated in northern Europe and the homes with this certification have no energy cost, except for the ventilation system pump, which operates on aerothermal energy. Moreover, this system has a recovery unit that can reach up to 70% of the energy generated at zero cost.
• LEED Certification. It could be translated as "Leadership in Energy and Environmental Design" certification. It is a program that evaluates green buildings to recognize best practices and strategies for environmental care. It is voluntary and takes into account how waste is eliminated and where energy comes from.
• BREEAM Sustainable Construction. Besides being transparent and technical, it has nearly three decades of experience in England and is based on technical excellence and building modernization to assume sustainable functions. It is a certificate fully adapted to the language, regulations, and construction practices in Spain. It is easy to apply as a technician is not necessary, since only BREEAM staff will inspect the house once constructed.
• There are other certificates, such as GDC Vende, Minergie, or DGNB. They all share some common lines.

The future of sustainable houses is more than assured, thanks to European regulations that force the application of nearly zero consumption policies. Adapting to one certificate or another will be the decision of the builders, but undoubtedly offers guarantees to both buyers and those who build the project. The technicians of these certifications assure that the project will be truly ecological.