HOW TO READ THE ENERGY CLASS OF A HOUSE?

The Ministerial Decree 162/15 has definitively sanctioned the entry of the energy certification of buildings in the Italian law. Houses and apartments are now divided into energy classes, based on structural and functional parameters that scientifically determine the limited use of energy.

The primary function of the energy classification is therefore to establish what is the consumption of a building, or better said, what is the impact in terms of consumption that the building has on the environment. The objective of the legislator, which only requires energy certification in certain circumstances such as deeds, rental agreements, applications for discounts and deductions, is to limit energy waste, reduce consumption and encourage citizens and the market to use new technologies, offering alternative solutions with low environmental impact.

WHAT IS THE A.P.E., THE ENERGY PERFORMANCE CERTIFICATE?

A.P.E. (Energy Performance Certificate) is the document that describes the annual amount of primary energy appropriate to meet the energy needs of the building. This model replaces the A.C.E. (Energy Certification Certificate) introduced by Law 90/2013, thus unifying at national level the energy classification based on standardized characteristics and methods.

The law imposes the obligation to present this certification when placing a house on the market or when carrying out works that change the energy performance of buildings and facilities. To be precise, it is necessary to equip a building with the A.P.E. when :

The certificate is issued following an on-site energy analysis of the building. The elements that are taken into consideration are the following
The energy classes are 10 in number and range from G, the worst in terms of efficiency, to A4, the most efficient. These are flanked by the NZEB class, which is the most virtuous so far, with almost zero energy.

WHO CAN WRITE THE E.P.A.?

The A.P.E. must be established by a technician approved by the Region in which the property is rented. The professional, usually an architect, engineer or surveyor authorized to design facilities and buildings, must be a person who is not related to the person who designed and/or built the building.

HOW TO READ THE ENERGY CLASS OF A HOUSE?

In order to evaluate the energy efficiency of a building, it is necessary to give indications both on the performance of the systems, such as hot water production, heating and air conditioning when present, and on the capacity of the slabs and walls, used both to separate the heated areas from the unheated rooms and from the outside, as these are capable of retaining the heat inside the house.

In order to make the information of an E.P.A. certificate more understandable even for those who are not technicians of the sector, we analyze the main elements:

Identification code: corresponds to the value assigned following the transmission procedure directly from the regional information system.
Validity: the certification lasts for 10 years if, and only if, the deadlines for the control of the installations are met and no work is carried out that substantially changes the energy characteristics.
Intended use: Presidential Decree 412/93 indicates E1 as the category to which buildings used as homes and similar buildings belong.
Identification data: in addition to the cadastral data, latitude and longitude coordinates are needed to uniquely identify the property.
Climatic zone: this data obviously depends on the municipality in which the building is located and is mainly used to indicate how many hours per day and during what period it is possible to turn on the heating.
Useful surface: this data indicates the net surface of the volume affected by the air conditioning with a height of more than 150 cm. It is calculated by adding all the cooled or heated surfaces. This value is very important because it is the one used to calculate the energy performance indices.
Energy services: Services suitable for calculating energy performance, such as heating and hot water, are listed here. If the building does not have these, the procedure would be simulated by indicating this in the systems table.
Building Energy Performance: The figure refers to the energy performance of the building envelope, i.e., how well the building, minus the performance of the facilities, uses energy in winter and summer. The quality levels, high, medium and low, are indicated by the use of a smiley face.
Overall energy performance and building performance: this is certainly the most important fact of the certification because it determines the actual energy class of the building. On the left side of the representation are all the bands, while the right side indicates by an arrow the letter assigned to your building, with the corresponding number of kWh/m² per year.
Energy performance of the systems: this value indicates the amount of fuel consumed by the building in one year and with standard use.
Energy requalification: this data is mandatory and its absence excludes the validity of the whole certification. Here you will find the description of all the recommended interventions to improve the environmental impact of the building.
Information on improving energy performance: this space is dedicated, for example, to the inclusion of incentives and legislation to support the modernization of buildings in terms of consumption.
Inspection, data entry and issuance of data: all these steps are mandatory for the certificate to be valid. The responsible technicians must also sign and stamp the original E.P.A.

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