Tell me the age of your home and I will tell you the key reforms to have a sustainable and efficient home

Our country’s real estate stock is old. On average, Spanish properties are over forty years old, with 42% of them built between 1950 and 1980 (10.4 million) and almost 30% (6.5 million) before 2000, according to data from the INE and the Ministry of Development.

Before 1900, from 1900 to 1950, from 1950 to 1980, from 1980 to 2000, from 2000 to 2011, from 2011 to 2020

Graph: age of the housing stock (source: INE and Ministry of Public Works).

 

To this must be added that the sale and purchase of newly built properties, although it has grown recently, is still a minority, as from 2012 to 2020 only about 700,000 homes were built in Spain. Thus, second hand represents 8 out of every 10 operations. Most of these homes need refurbishment work to improve their condition and habitability, as well as to become efficient and sustainable properties.

In fact, more and more Spaniards are opting to renovate their homes in order to have a healthier and more sustainable home. The construction sector estimates that last year, despite the restrictions by the Covid-19, there was an increase of around 5% of reforms of houses and buildings compared to 2019.

Given this growing interest in property refurbishment, which will also count on an injection of 5,800 million from European funds within the Plan for the Recovery, Transformation and Resilience of the Spanish Economy, we have analyzed, together with our leading channel in home refurbishments, créditos.com, the key refurbishments and the estimated cost it would have to reconvert a property into an efficient and sustainable home depending on its age.

 

Homes 40-70 years old (those built between 1950-1980): according to the INE and the Ministry of Development, 10.4 million homes in our country (42%) are of this age. They are especially common in the Basque Country, which has 53% of dwellings of this period; the Community of Madrid, with half of its buildings erected in these decades; Catalonia, with 48%, and the Community of Valencia, with 44% of properties of this age.

These are homes with concrete structures based on aluminous cement and, in many cases, of poor quality construction materials, so the structure may be quite affected today. In addition, they do not take into account any efficiency or sustainability criteria.

The first step should be the reform of its elements of connection with the outside, especially the exterior walls, the facade and, after this improvement, the change of windows. The estimated cost would be between 20,000 and 40,000 euros, in a house of between 90 and 120 square meters, which is the average in our country. However, these structural changes usually affect the building as a whole.

In addition, it is necessary to take into account the state of its installations, such as the electricity or plumbing systems, often made of lead or galvanized steel, materials that represent a health risk for the inhabitants. The most advisable thing to do is to completely change the installation and avoid making ‘fixes’ between old and new materials, as they tend to coexist poorly.

 

-Homes 20-40 years old (those built between 1980-2000): 6.5 million properties in Spain (27%) correspond to this period, according to data from the INE and the Ministry of Development. Again, with differences by Autonomous Communities, Andalusia (32%), the Canary Islands (32%), the Region of Murcia (32%), Extremadura (31%) and Castile-La Mancha (30%) are the regions with the most homes of this age.

These buildings are characterized by a better quality of materials than in previous decades, but were built before the current Building Code came into force. Therefore, they do not take into account efficiency and sustainability criteria or the use of sustainable energy sources.

For example, in this type of buildings the window system is usually aluminum, so changing them for hermetic closures and double glazing will allow energy savings of up to 30%. It is also advisable to install insulation such as polystyrene, mineral wool, EPS sheets or wood fiber panels in walls and ceilings.

Another possible reform in homes of this age is the installation of underfloor heating to replace old parquet floors and heating systems, which could cost between 12,000 and 16,000 euros on average. In addition to the renovation of kitchens and bathrooms, the cost of which ranges between 10,000 and 20,000 euros.

 In short, taking into account these improvements, the rehabilitation of a house of this age, between 90 and 120 square meters, could cost between 20,000 – 30,000 euros.

 

Homes 10-20 years old (built between 2002-2011): homes built 10 or 20 years ago represent 18% of the housing stock. By regions, there are more constructions of this type in La Rioja (25%), Region of Murcia (24%), Galicia (23%) and Castilla-La Mancha (22%).

These buildings have been built in accordance with energy efficiency standards. However, their materials and structure are designed to insulate the house from the outside, so it is advisable to carry out maintenance work to ensure that the heating system is in good condition and that windows, floors and walls are optimally insulated. 

However, in these homes, one of the main improvements to help care for the environment is the replacement of inefficient heating systems, such as gas, with renewable systems, such as aerothermal or geothermal energy, which, with an investment of between 10,000 and 25,000 euros, can save between 35% and 70% on energy bills.

As for the generation of hot water and electricity, the main source of energy is still not renewable in many homes. The solution would be to opt for the installation of photovoltaic and thermal solar panels. Likewise, home automation, which makes an important contribution to making a home more efficient, is still residual in recently built properties.

 

All these reforms are generic guidelines for the creation of a sustainable home with greater comfort and habitability, but each property has specific characteristics, so the best option is to consult with a professional to indicate the most appropriate and the specific budget depending on the needs and extent of housing.

In addition, it is necessary to bear in mind that big structural changes, as the facades or central heating systems, go through the rehabilitation of the whole building, it is not enough to do it only in our house. In this sense, the average price of the rehabilitation of a community of neighbors can be around 100,000 euros on average, always depending on each specific case.

For these rehabilitations in favor of sustainability and energy efficiency, both in buildings and neighborhood communities, there is a program of public subsidies, complemented by private loans such as those offered by créditos.com, with a lower interest rate because they are reforms that improve sustainability in the home.