Energy certification for old houses

What is energy certification?

Energy certification is a document that assesses the energy performance of a building, giving it an efficiency rating on a scale from A+ (most efficient) to F (least efficient). This process analyses various factors, such as thermal insulation, heating, ventilation and air conditioning systems, type of windows and building materials.

In Portugal, energy certification is compulsory for new and existing buildings when they are put up for sale or rent. The main aim is to promote energy efficiency and inform consumers about the energy costs associated with each property as well as the improvement measures they can implement and the respective benefits in terms of energy consumption.

Is the energy certificate compulsory for old houses?

Portuguese legislation on energy certification of old buildings is defined by Decree-Law no. 118/2013 of 20 August. This law states that all houses, regardless of how old they are, need an energy certificate if they are placed on the market for sale or rent.

The certificate must be presented before the purchase, sale or rental contract is signed, guaranteeing transparency about the property’s energy performance. In addition, whenever a building undergoes interventions of more than 25 % of its value, it will be compulsory to obtain a new energy certificate.

Challenges in energy certification of older homes

Older homes, especially those built before the implementation of energy efficiency standards, can have a lower energy performance due to factors such as:

• Lack of adequate insulation in the roof;
• Single-glazed windows that don’t provide enough insulation;
• Inefficient or non-existent heating and cooling systems.
• Despite the challenges, energy certification can help homeowners identify opportunities for improvement, such as installing double glazing, thermal insulation or more efficient heating systems, which can reduce energy costs and increase the value of the property.

Situations where an energy certificate is not required

Although energy certification is a legal requirement in most cases, the legislation provides for some exceptions in which it is not necessary to obtain an energy certificate:

• Single-family buildings with a floor area of 50 m² or less, provided they are autonomous;
• Buildings in ruins, when intended for total reconstruction

Conclusion:

Energy certification is an essential tool for promoting energy efficiency and transparency in the property market. In the case of old houses, although it can be a challenge to get a good rating, the certificate provides valuable information for owners and buyers. As well as being a legal requirement, investing in energy efficiency can increase home comfort.

If you need more information about the certification process or want to improve the energy efficiency of your property, consult a qualified expert for detailed guidance.