Damp, humidity and heating: what Mallorcan houses are like in winter

Mild outside, chilly inside

Visitors are often surprised that a Mallorcan house can feel colder in January than a home in northern Europe. The island’s winters are mild and relatively wet, and the air is often humid, especially near the sea. Many houses were built for the summer: thick stone walls, small windows, tiled floors and shutters to keep the heat out. That works well in August. In winter, without good heating and insulation, those same walls stay cold, and moisture settles on them.

Spain had no national rules on thermal insulation until 1979, and much stricter energy and damp-protection standards only came with the Building Technical Code (Código Técnico de la Edificación) in 2006. So the age of a house, or of its last full renovation, tells you a lot about what to expect.

Three kinds of damp

Damp has several possible causes, and the cure depends on which one you have. A building surveyor will try to tell them apart.

Rising damp

Water drawn up from the ground into the base of walls. Common in old houses built straight onto the earth without a damp-proof layer, especially in porous stone such as marès, the soft sandstone-like rock used across the island. Signs: tide marks, flaking plaster and white salt deposits on the lower walls.

Penetrating damp

Rain getting in through roofs, flat roof terraces, cracked render, gutters, window frames or walls built into a slope. Signs: patches that grow after storms, often high up or around openings.

Condensation

Moisture from cooking, showers, breathing and drying washing settling on cold surfaces. Signs: black mould in corners, behind furniture and on north-facing walls, wet windows in the morning.

Marès is so porous that water can travel a long way up a wall, and covering the base with tiles or impermeable render can push it higher still. That is why some well-meant repairs make things worse, and why it pays to have an expert look at the wall before anyone seals it.

Insulation, windows and roofs

• Single glazing and old timber or aluminium frames lose heat and let in draughts. Double glazing is now common in renovated homes, but check it has been fitted all round.
• Roofs on old village houses often have little or no insulation. Ask what was done when the roof was last repaired.
• Cold bridges, such as concrete beams or balconies running through an outside wall, show up as dark lines of mould.
• Houses empty for most of the winter suffer most. A home that is heated and aired regularly is much easier to keep dry.

How Mallorcan homes are heated

There is no single standard. What you find depends on the age of the house, whether there is piped gas, which reaches Palma and a number of other towns but not everywhere, and what the last owner invested in.

Underfloor heating suits tiled floors, and in a well-insulated house it keeps the whole floor warm, which helps against damp. Whatever the system, see it running, ask how long the house takes to warm up, and ask for winter energy bills.

The energy certificate

Every home offered for sale in Spain must have an energy performance certificate, with a rating from A to G that has to appear in adverts (Real Decreto 390/2021). It is a useful first indicator, but it is a calculation based on the building’s features, not an inspection, and it will not tell you whether a wall is damp. Many old stone houses score low. That does not make them bad homes, but it does tell you to budget for improvements.

What to ask a surveyor

• Where is the damp, what kind is it, and what is causing it?
• Is the base of the walls breathable, or has it been sealed with cement render or tiles?
• What state are the roof, the flat terraces and the gutters in?
• Is there any insulation in the roof and walls, and what would adding it involve?
• Is the heating system the right size for the house, and how old is it?
• Are timber beams sound, given that damp encourages rot, woodworm and termites?
• Roughly what would the essential work cost, as a basis for negotiation?

Spain has no standard pre-purchase survey, so you have to commission one yourself, usually from a technical architect (arquitecto técnico). Our guide to surveys and checks explains how.