Spain is not cold, the argument goes, so heating is an afterthought. Then January arrives in a Maresme villa with single glazing, no insulation in the roof and a gasoil boiler from 2004, and the first refill costs more than a flight to Helsinki. The fuel matters. What matters more is the house wrapped around it.
If the building has a natural gas connection and a boiler feeding radiators, you are in the cheapest normal case. On the regulated TUR.2 tariff the variable term has hovered around five cents per kWh through late 2026, and a 100 m² flat with reasonable habits spends roughly €600–750 across the heating season, November to March. A well-insulated flat with neighbours on both sides can be half that. A top-floor corner with single glazing can be double.
Two things trip people up. The first is the standing charge, which you pay whether the heating is on or not. The second is hot water: in most Spanish flats the same boiler makes it, so a long shower in August still shows up on the gas bill. Neither is a scandal, but both explain why the summer bill is not zero.
A plug-in oil-filled radiator turns one kWh of electricity into one kWh of heat. There is no trick, no coefficient, no efficiency gain. At €0.20–0.28 per kWh including taxes, heating a 100 m² flat through the winter that way lands somewhere between €1,500 and €2,000, and a villa with five of them running in the evening goes past that without trying.
The exception is a reversible split, which is a heat pump wearing an air-conditioner costume. It moves three to four kWh of heat for every kWh it consumes, so the same room costs a third of what a radiator costs. If a villa has splits in the bedrooms, use them in heating mode in December and February; that is what they are for. The catch is that blowing warm air at ceiling height is not the same comfort as a radiator under the window, and the filters need cleaning or the whole thing smells of dust by January.
Walk through any older barri in Barcelona or a village in the Maresme in winter and you will hear the trucks. The 12.5 kg orange bottle is price-regulated and sat at €18.89 on the peninsula from 1 October 2026. There is no standing charge and no contract: you buy the bottle, you carry it up, you connect it to a heater or a small water boiler.
How long a bottle lasts is the only number that matters. Heating one room for four or five hours in the evening, roughly a fortnight. Two rooms and a bathroom water heater, a week to ten days. That is €40–60 a month in a mild month and €100+ in a cold one, plus the mild indignity of scheduling your life around the reparto. For a studio it is a perfectly rational system. For a four-bedroom villa it is not a system at all.
Plenty of houses on the coast were built before the gas network reached the hills, so they run on gasóleo in a tank buried in the garden or sitting in the utility room. The fuel was around €1.45–1.75 a litre in October 2026 depending on where you look and when it was measured. A 200 m² villa with radiators, single glazing and a family that likes 21°C will burn 1,500–2,500 litres across a winter. Do the multiplication and you are at €2,200–4,000, plus the annual boiler service and the risk that the tank is older than the burner.
If you are renting such a house, the tank level on the day you arrive is a real number, not a detail. Photograph the gauge, get it written into the inventory, and agree in the contract who pays for the first fill and who pays for the last. We have seen a €900 argument at the end of a winter let that would have taken one sentence to avoid.
A Spanish house built for summer is a specific thing: thick walls that keep the heat out, shutters that close at midday, tiles over concrete, and almost no thought given to keeping warmth in. That is wonderful in July. In January it means the 12°C outside is also 15°C in the hallway, because the sun is low, the tiles are cold, and the sea air has put a dampness into the walls that no radiator fully removes.
So look at the envelope before you look at the boiler. Single glazing vs double, shutters that actually close, ceiling height (3.5 m in a finca regia is beautiful and expensive to heat), orientation, whether the roof has insulation, whether there is underfloor heating or just radiators from 1985. A €40 tube of silicone around a draughty window frame can do more than a bigger boiler. And a dehumidifier at €200 often makes a 16°C room feel like 18°C for a fraction of the cost of raising the thermostat.
For a 100 m² flat in Barcelona or the first Maresme ring, December to February: gas radiators €120–180 a month, electric radiators €250–350, butano for two rooms €60–100 plus the logistics, reversible splits used sensibly €70–120. For a 200 m² Maresme villa with gasoil, €400–700 a month is normal and €900 is not a scandal in a cold snap. These are ranges, not quotes; the envelope decides.
One last local note. The Maresme winter is mild on paper — January nights around 6–9°C, days near 13°C — but the humidity off the sea makes it feel colder than a dry 5°C inland. Tenants from the UK or Germany consistently underestimate this. Bring the wool, ask about the dehumidifier, and do not assume that because the house is expensive it is warm. Some of the coldest January evenings we have had were in villas with a sea view.
Tell us the size of the house and how you like to live — radiators on all day, one warm room in the evening, underfloor heating or nothing. We will tell you which fuel each villa actually runs on and what the winter will cost before you commit.
Ask about winter heating Download the winter rental checklist (PDF)