In the central parts of Spain they do have heating systems and proper insulation. Winters are cold there, just not as cold as this year.

I wouldn't extrapolate.

Most places in Spain have and need heating, apart from a few coastal enclaves in the south. Spain is the 5th largest user of energy for residential heating in the EU, behind Germany, France, Italy, and Poland.

I agree this is rather limited to the south coast and the islands. But I would argue that high energy consumption could, in this case, very well be the sign of poor insulation and inefficient heating installations (A/C).

On what grounds would you base that on beyond your prejudices?

I'm sorry if it came out as prejudicial. It was not intended in this way. It was more of an observation after having lived there for some years and witnessed it first hand.

I did a quick search for more objective observations and what I found was:

Homes labelled A, B and C account for less than 10% of the housing stock. […] Most of households in the sample (52%) are E rated. F and G rated residences account for almost 25% of the sample. [1][2]

In Spain, buildings are currently responsible for 31% of energy consumption. […] the classification A - the highest - involves spending up to 10 times less than the G - the lowest -. Currently, in Spain most buildings have an E, F or G rating.[3]

[1] https://www.sciencedirect.com/science/article/pii/S030142151... (4. Results and discussion)

[2] https://en.wikipedia.org/wiki/European_Union_energy_label

[3] https://www.interregeurope.eu/enerselves/news/news-article/2...