Sunscreens and minimum requirements
Technically, solar shading, a category which also includes curtains, includes all of them “technical” structures applied inside, outside or integrated with the glass surfacewhich guarantee a solar transmission factor, coupled with that of the glass surface which they cover, lower than or equal to the value of 0.35 evaluated with reference to type C glass according to the UNI EN 14501 standard.
Since the objective of solar shading and therefore the reason for the deduction is the reduction of heat inside the buildingthese structures can be installed exclusively to protect windows overlooking the walls exposed to the South, East and Westand they must be mobile to be able to adapt to variations in sunlight throughout the day.
To be able to return to the relief the shielding must therefore be:
- applied integrally with the building envelope and not freely mountable/demountable from the awnings;
- to protect a glass surface;
- mobile;
- made with materials with specific technical characteristics.
No concessions therefore for simple furnishing elements, as expressly reiterated by the Revenue Agency with circular 28/2022.
Characteristics and reference technical standards
Specifically, the technical characteristics are those indicated in Annex M to the Legislative Decree. 311/2006 regarding energy performance in buildings.
The annex contains the technical standards relating to methodology for calculating energy needs indicating as a reference the UNI and CEN regulations in force relating to the reference sector.
In the case of external solar shading the technical standards are as follows:
- UNI EN 13561 External awnings performance requirements including safety (CE marking is mandatory);
- UNI EN 14501 Thermal and visual well-being, performance characteristics and classification;
- UNI EN 13363.01 Sun protection devices in combination with glazing; calculation of total and luminous transmittance, simplified calculation method;
- UNI EN 13363.02 Solar protection devices in combination with glazing; calculation of total and luminous transmittance, detailed calculation method.
Which tents with the Bonus
In respect of requirements as soon as you see the curtains they can be of all types typesor:
- roller blinds;
- roller blinds;
- arm awnings;
- curtains with adjustable slats (Venetian);
- textile covers for gazebos;
- sunshade awnings.
The technical characteristics must be certified by the manufacturer.
Deductible expenses
The Ecobonus is for expenses actually incurred For:
- supply and installation;
- temporary and accessory works;
- professional services necessary for the realization of the works and the necessary technical documentation.
In case of replacement of old solar screens certification is required that the new installation guarantees an improvement in terms of energy savings, otherwise the bonus is not permitted. In this case, however, the deductible expenses also include any dismantling and disposal of the old shielding.
For the benefit you must complete the practice at ENEA And attach the certification of the requirements and maximum costsin compliance with the Ministerial Decree of 14 February 2022 issued by the Ministry of Ecological Transition which in Annex A establishes the maximum specific costs that can be subsidized for the types of intervention that affect the energy efficiency of buildings, including solar shading. In this case it is about 276 euros per square meter.
The maximum cost does not include VATnor any professional services incurred, nor works strictly related to the intervention, nor the labor for installation. The limit therefore concerns supply only.
The calculation of energy savings
As mentioned, only shields that comply with the minimum energy saving requirements foreseen depending on the climate zone are eligible. Because of this ENEA provides an application free of charge of assistance for users and technicians for the calculation of the annual savings of non-renewable primary energy for solar shading at this address.
To compile it, remember that the existing heating system, if present, must be inserted. If there is a summer air conditioning system in the property unit subject to the intervention, the box must be ticked “Presence of summer air conditioning system” since the screens protecting glass surfaces develop their energy saving function essentially in the summer season. However, in the absence of the specific system, there is the possibility of entering the value “0” in the field relating to “Estimated savings of non-renewable primary energy”.
Bonus also for mosquito nets
Mosquito nets can also be included in the field of solar shading, in compliance with the requirements just seen. It was the Revenue Agency itself, with legal advice 10/2020, that gave full recognition to mosquito nets as a darkening element, thus recognizing the possibility of a subsidized purchase.
Obviously to be considered as darkening systems, mosquito nets they must present the characteristics required to be part of the solar shading category, therefore guaranteeing, combined with the glass, the required solar transmittance factor.
