Why Spanish homes feel so cold in winter

Key rules

• Building age: Homes built before 1979 are usually the coldest, and homes built after 2013 usually need the least heating.
• Cheap first: Draught sealing and thermal curtains usually give the most comfort for the least money, so do them before buying heating.
• Energy certificate: Ask for the certificate before you commit, but remember its rating is calculated on standard use, not real bills.
• Renters: Get your landlord's written consent before fitting anything fixed or changing windows.

Why your home feels cold

Indoor cold in Spain comes from two things: old buildings with poor insulation, and heating that is switched on only when needed. Outside temperatures are often mild, so the cold surprises people. Low-cost fixes help most, and they come before any costly heating system.

The age of the building matters most

Spain had no national thermal rule before 1979. Homes built before then usually have uninsulated walls, single glazing and many gaps. Heat escapes fast.

• Before 1979: typically the coldest and the most expensive to heat.
• 1980 to 2006: usually some wall insulation, and double glazing in later years. Quality varies a lot.
• After 2006: better walls and windows, with stricter rules in later updates. Homes built after 2013 usually need the least heating.

These are typical patterns. Individual buildings vary, so look at the actual home.

Heating is on and off

Many households heat one room for a few hours, not the whole home all day. Uninsulated walls then stay cold and the heat disappears quickly. Rooms also feel damp and chilly when you are not in them. Plan for this when you pick a home and when you budget.

Your climate zone

Every town has a climate zone code, such as D3 for Madrid or C2 for Barcelona. The letter shows winter severity, from α (mildest) to E (coldest). The number shows summer severity, from 1 to 4. Burgos is E1, a cold winter zone. Sevilla is B4 and Málaga is A3. The energy certificate lists the zone of the home. The transport ministry also has a lookup by municipality.

Check the energy certificate before you commit

Ask the owner or landlord for the certificado de eficiencia energética. It rates the home from A (most efficient) to G. It also shows the heating demand, the type of heating, the walls and windows, and suggested improvements with estimated costs. It is valid for 10 years.

The rating is calculated on standard use, not on real bills. Your actual consumption will differ. A low rating still tells you the home is likely to be cold.

What helps, in order of value

Start with the cheapest measures. They are listed in the checklist below. In order of usual value:

1. Seal draughts around windows, doors and shutter boxes. This is cheap and often gives the biggest gain.
2. Heavy thermal curtains, closed at night.
3. Insulating film on single-glazed windows.
4. Open shutters and curtains by day on sunny south-facing windows.
5. Reflective panels behind radiators, rugs, and draught excluders under doors.
6. Block unused chimneys and extractor vents.

Costs run from a few euros to a modest amount per window. The saving depends on the state of the home. Check prices at a local hardware shop.

If you rent, get your landlord's written consent before fitting anything fixed or changing windows. The checklist covers this.

Costly systems come later

Do not buy a new heating system first. If the walls and windows leak heat, a bigger heater mostly warms the street. Fix the leaks, then see what heating you still need.

Documents you need

• Energy efficiency certificate (certificado de eficiencia energética): ask the owner or landlord for it. It shows the A to G rating, heating and cooling demand, climate zone and suggested improvements. It is valid for 10 years and registered with the regional authority.

Low-cost comfort fixes for a rented flat

Low-cost comfort fixes you can make in a rented flat

• Seal gaps around windows, doors and shutter boxes with weatherstrip and silicone.

• Hang heavy thermal curtains and close them, and any blinds, at night.

• Stick removable insulating film or bubble film on single-glazed windows.

• Open shutters and curtains by day on sunny south-facing windows to let the sun warm the room.

• Put reflective panels behind radiators, lay rugs on bare floors and place draught excluders under doors.

• Block unused chimneys and extractor vents.

• Use removable fans, portable heaters or dehumidifiers, and free-standing furniture. You can do all of these without asking your landlord.

• Ask for your landlord's written consent before you fit a fixed split air-conditioning unit, change windows or put an awning on the facade.

• In summer, lower blinds or shutters on sunny windows by day, keep windows shut in the hottest hours and ventilate at night.

• If you use air conditioning, set it no lower than about 26 °C and use a fan where you can.

• Tell your landlord at once about urgent repairs, such as a broken window or a heating fault.

Frequently asked questions

Are homes built before 1979 colder than newer ones?

Yes, homes built before 1979 are usually the coldest, because no national thermal rule existed before then. Walls are often uninsulated and windows single-glazed. Homes built after 2006 usually have much better walls and windows, and those built after 2013 need the least heating.

How can I find out which climate zone my town is in?

You can find your town's climate zone in the Ministry of Transport's zone lookup tool by municipality. The zone is a letter for winter (from α, the mildest, to E, the coldest) and a number for summer, such as D3 for Madrid or E1 for Burgos. Higher towns are usually colder than the provincial capital.

What does the energy certificate tell me about heating needs?

The energy certificate shows the home's heating and cooling demand in kWh per m² per year, plus its rating from A to G. It also lists the heating system, the walls and windows, and suggested improvements with estimated costs. It is calculated on standard use, not real bills, so your actual consumption will differ.