How to calculate the optimum SATE thickness? Our guide

The calculation of the optimum thickness of the external thermal insulation system (EIFS) will depend on several factors, such as the climate of the area, the type of construction, the use of the building and the insulation material used.

However, a general way of calculating the optimal thickness of the ETICS is through the use of thermal simulation tools. These tools allow the thermal behaviour of a building to be modelled and the impact of the thickness of the ETICS on energy consumption and greenhouse gas emissions to be assessed.

In general, a balance is sought between the cost of the ETICS and the energy savings it provides. Excessive thickness can significantly increase the cost of the system, while insufficient thickness may not provide adequate thermal insulation and may not achieve the desired energy savings.

It is recommended that you consult a professional in the design and construction of buildings with experience in the use of thermal transmittance calculation tools to determine the optimal thickness of the SATE in your specific case. In addition, Molins offers you its new SATE Calculator, to provide another assessment for your project.

What is the thickness of the façade with the SATE system?

With a SATE system, the exterior of the building is clad and insulated, adapting the building’s geometries, even the most complex ones, without discontinuity, as explained in the SATE Guide for the Renovation of the Thermal Envelope of Buildings of the Institute for Energy Diversification and Saving (IDAE).

Therefore, when properly designed and installed, it easily resolves most of the building’s thermal bridges, the guide says. The SATE systems that incorporate insulation with an optimal thickness ensure drastic reductions in the energy dissipated to the exterior, demonstrating a reduction in fuel consumption of close to 30% and allow for consistent and continuous energy savings (heating in winter; air conditioning in summer). It is estimated that the investment made for the installation of the system is amortised, on average, over the following five years.

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Thickness in the SATE system: Technical Building Code (Código Técnico de la Edificación, CTE)

The External Thermal Insulation System (SATE) improves the thermal insulation of buildings, thereby reducing energy consumption and CO₂ emissions into the atmosphere. The Technical Building Code (CTE) establishes minimum thickness values for the thermal insulation of buildings depending on the climate zone in which they are located.

In climate zone A, which includes northern Spain and high mountain areas, the minimum thickness of the SATE should be 60 mm.

In climate zone B, which covers most of the Iberian Peninsula, the minimum thickness of the SATE must be 50 mm. In climate zone C, which includes the south of the Iberian Peninsula and the islands, the minimum thickness of the SATE must be 40 mm. And finally, in climate zone D, which corresponds to the hottest and driest areas of the country, the minimum thickness of the SATE must be 30 mm.

In order to calculate the required thickness of a building’s insulation, it is important to take into account several factors, such as the climate zone in which the building is located, the characteristics of the insulation materials, the orientation of the building and the type of cladding. In general, the higher the heating demand in winter and the higher the cooling demand in summer, the greater the required thickness of the EIFS.

It is important to note that the CTE establishes minimum thickness values for the SATE, but in many cases it may be necessary to increase this thickness to achieve greater energy savings and energy efficiency of the building. In any case, it is important to make sure that the thickness of the EIFS complies with the requirements of the CTE and with the energy needs of the building in question.

In conclusion, the thickness of the insulation is a key factor in improving the energy efficiency of buildings, and its calculation should take into account the climatic zone in which the building is located, the characteristics of the insulation materials and the energy needs of the building.

Compliance with the minimum thickness values established by the CTE is essential to guarantee correct thermal insulation and reduce the energy consumption of buildings.

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How to calculate the thickness with the SATE System?

Below, we detail the steps for calculating the thickness with SATE:

1. Identify the climate zone: as mentioned above, the CTE establishes minimum values for the thickness of the SATE depending on the climate zone in which the building is located.
2. Knowing the characteristics of the insulating materials: the thickness of the SATE will depend on the characteristics of the insulating materials used, such as their thermal conductivity and density.
3. Analyse the orientation and type of building envelope: The orientation of the building and the type of building envelope also influence the calculation of the insulation thickness. For example, a building with a favourable orientation towards the sun may require less insulation thickness than a building with an unfavourable orientation.
4. Carry out a thermal calculation: in order to obtain the optimum thickness of a building’s ETICS façade, it is advisable to carry out a thermal calculation that takes into account all the variables mentioned above, as well as the building’s energy needs.

Try our new SATE Calculator

Recently, we have added a new functionality to our website, to calculate SATE projects.

One of the most interesting aspects of the calculator is that, when you enter your postcode, it tells you the climate zone where you live, and when you indicate the characteristics of the substrate, it automatically calculates the thickness required for the renovation, according to the CTE.

SATE Calculator

Learn more about Sustainable Construction: Plant-based panels (SATE System)

It is important to emphasise that the calculation of the thickness of the ETICS should be carried out by a technician specialised in energy efficiency or by an architect with experience in thermal insulation. In addition, it is essential to ensure that the materials used comply with the technical and regulatory requirements in each case.

At Molins, we have a technical area with which we provide our customers with a whole series of tools to facilitate their work and their day-to-day. Do not hesitate to contact us.

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