Energy certificates for Nearly Zero Energy Building

The Nearly Zero Energy Building is already a reality. Since 2018, all publicly funded buildings must adapt to the requirements imposed by the European Union in this regard, and starting in 2020, all private tenders must also follow these criteria. However, in Spain, there is still too much ignorance related to this way of designing buildings, both at the architectural and design level, as well as in their development. That is why existing energy certificatesthat endorse the energy efficiencyof a building can help comply with European regulations.

The energy certificates for buildingsthat evaluate the sustainability of a building are voluntary, but in recent years they have become a reference for the sector and also for the end consumer when it comes to assessing indoor energy consumption. Some of the most important are the Passivhaus, BREEAM or LEED. Each of them has specific strengths, but their goals are similar, as they measure and certify the degree of energy efficiency of a construction.

Following the parameters of each of these certificates, it is possible to adapt to the Nearly Zero Energy Buildingin a straightforward way. What does the European regulation require of buildings also known as nZEB? While there are a series of conditions, the most important are three:

• Controlled lighting. In addition to having low-consumption lighting systems, technologies that take advantage of sunlight should be used, and orientation should be studied to minimize lighting expenditure. It is essential to make the most of sunlight.
• Minimal air conditioning. Passive cooling solutions should be created in summer, and a high airtightness must ensure minimal heating consumption during winter. In addition to thermal insulation, it is important to have options such as ventilated roofs and other ways to save energy.
• Efficient ventilation systems. In the Nearly Zero Energy Building, one third of the consumption can be allocated to ventilation, so it is very important to have high energy efficiency systems, such as double-flow ventilation.

With the energy certificatesthat evaluate the sustainability of buildings, it is possible to meet these requirements for Nearly Zero Energy Buildings, as the interests are similar. Both high airtightness and mechanical ventilation, along with lighting conditions, are characteristic aspects of energy labelssuch as Passivhaus or BREEAM. Their application would also help comply with the requirements of the European Union.

What nearly zero consumption measures do energy certificates provide us?

In the case of BREEAM, as well as Passivhaus and LEED, the acquisition of the energy labelguarantees that the building meets minimum energy efficiencycriteria, although there are scales to certify to what extent it is sustainable.

In the case of Passivhaus-which is one of the benchmarks in the industry throughout Europe-, the three main characteristics of the Nearly Zero Energy Buildingare perfectly met.

Passivhaus advocates a model of passive houses, where all energy is of minimal cost, and energy processes are carried out passively, without using the supply:

1. In terms of lighting, it advocates full use of sunlight. Solar panels can also be installed to ensure that electric lighting comes from renewable sources.
2. The core of passive houses is a type of construction that eliminates the need for air conditioning units. To achieve this, Passivhaus proposes applying measures for thermal insulation, ventilated roofs and facades, a particular orientation, and other solutions to avoid the use of air conditioning units.
3. The only mechanical consumption element permitted in passive houses is mechanical ventilation. Therefore, aerothermal systems are used, which allow for heat recovery in winter and cooling in summer. Considering that the Nearly Zero Energy Buildingallows for mechanical ventilation, the Passivhauslabel fully adapts to community requirements.

The BREEAMlabel is another of the energy certificatesthat prioritize energy efficiency, but it also emphasizes user comfort. Therefore, it takes into account other factors such as sound insulation and ensuring that the air is pure and clean.

BREEAM has ten required sections, including energy management and increased ecology, as well as waste management. It also applies measures for lighting savings and thermal insulation, making it an excellent fit for the needs of the Nearly Zero Energy Building.

The application of these energy certificates, in addition to the also popular LEED, allows us to apply the requirements of the Nearly Zero Energy Buildingin a straightforward manner.