Anyone selling a house in Portugal is obliged to indicate the energy class in the advertisement, but they may be leaving out relevant information: heat pumps, solar panels, efficient windows or good insulation help to explain the comfort of the property and the energy savings that the buyer can experience.
Energy efficiency is no longer just a technical detail hidden in the certificate. In a market where heating and cooling the house weighs heavily on family expenses, the way this information appears in the advertisement can influence the perception of the property.
An American from the Smart Energy Consumer Collaborative, carried out in partnership with the National Association of Realtors and the 257 data platform, evaluated what happens when energy efficient equipment is highlighted in real estate advertisements.
The study analyzed 143 million real estate listings in the United States, between 1995 and 2025, and crossed the data with surveys of industry professionals and recent buyers.
In the case of houses with ducted heat pump systems sold in 2024 and 2025, advertisements referring to this equipment were associated with selling prices 0.6% to 1% higher than those in similar homes that also had a heat pump but whose advertisements did not mention it.
The result does not mean that installing a heat pump automatically increases the value of a house, and does not allow us to conclude that the same effect exists in Portugal.
The most prudent reading is another: when efficient equipment already exists, hiding it in the advertisement may prevent the buyer from realizing part of the property’s value.
The report itself shows how this information can go unnoticed. Heat pumps were only mentioned in 8% of advertisements for houses where they were present.
In Portugal, advertisements for the sale or rental of property, attributed to a valid energy certificate or pre-certificate.
The energy certificate identifies the efficiency of the property, but also includes information about components of the house and measures that can improve performance, reduce consumption and increase comfort.
This is where equipment such as heat pumps, solar panels, efficient windows or insulation systems come in, which can better explain the energy behavior of the house to the buyer.
Heat pumps are an increasingly common example. According to one from the European Commission’s Joint Research Center for the Portuguese market, around 40 thousand units were sold in Portugal in 2022, 24% more than in the previous year, increasing the installed base to around 277 thousand units.
The same document estimates that heating and cooling represent 49% of final residential energy consumption in the country.
For anyone preparing an advertisement, the conclusion is simple: the energy class letter is mandatory, but may not be sufficient.
If the house has a heat pump, solar panels, efficient windows, recent insulation or solutions that reduce consumption, this information must be clear. It does not guarantee a sale for a higher price, but it helps the buyer to better understand what they are actually buying.
