Risks With a House Built in the 1950s

The three things most worth your attention in a house from the 1950s are blue concrete (blåbetong) and radon, asbestos and an old electrical system without earthing. The rest of the list is the usual age-related wear you can check calmly and in your own time.

An old house is not the same as a house in poor condition. Many 1950s houses are solid and well built, and several of the risks below have already been dealt with in homes that have been renovated over the years. The aim here is not to frighten you, but to make sure you know what to ask the agent and the surveyor before you place a bid.

Blue concrete and radon

Blue concrete (blåbetong) is a lightweight concrete made from alum shale that was manufactured in Sweden between 1929 and 1975, which is right in the middle of the period when many 1950s houses were built. The material has an elevated radium content, and radium decays into radon gas, which raises the radon level indoors. Radon is invisible and odourless, but a high level over a long time increases the risk of lung cancer.

The reference level for radon in homes is 200 Bq/m3. If the house is below that level, all is well. The only way to know is a radon measurement, ideally a long-term measurement during the heating season.

What you check:

• Ask for the report from any earlier radon measurement.
• Look for blue-grey lightweight concrete in the walls.
• Note whether any readings are above 200 Bq/m3.

If there is blue concrete and elevated readings, it can be fixed, often with improved ventilation or a radon extractor (radonsug), which usually costs around 15,000-50,000 kr. Removing the blue concrete entirely is a bigger job and can cost considerably more, but that is rarely needed.

Asbestos

Asbestos has been banned for use in Sweden since 1982, but in a 1950s house it may still be present in several places: in eternit panels (eternitskivor) on the roof and facade, in floor tiles, in pipe insulation and in tile grout. Inhaling asbestos fibres can cause serious lung diseases, and roughly a hundred people in Sweden die each year from the disease mesothelioma.

The key thing to understand: intact, undisturbed asbestos becomes dangerous only when it is worked on, that is when you drill, demolish or sand it. As long as the material is left undisturbed and intact it rarely poses an immediate danger. Treat any material from before 1982 as suspect until proven otherwise.

What you check:

• Eternit panels on the facade or roof.
• Grey or black older floor tiles.
• Older pipes with white insulation.

If you plan to renovate, asbestos must be removed by a licensed firm. A removal job usually lands somewhere around 50,000-300,000 kr depending on the scope.

Unearthed electrical system

Many houses from this era still have parts of their original electrical system, and it often lacks earthing. That brings a risk of fire and electric shock, and the old wiring is also undersized for today’s needs with many appliances. The signs are fairly clear once you know what to look for.

What you check:

• Old screw-in fuses in the consumer unit (elcentral).
• Two-pin sockets without earthing.
• A missing residual-current device (jordfelsbrytare).

Replacing the consumer unit and parts of the installation usually costs somewhere around 50,000-200,000 kr. It is worth asking for documentation of when the wiring was last checked by a licensed electrician.

Other risks to check off

Most of the points below are about maintenance and age, not immediate danger. The costs are rough rules of thumb and vary a lot with condition and size.

Risk	What you check	Approximate cost
PCB in sealants (1956-1973)	Original sealants around windows and balconies, ask whether an inventory was done	30,000-150,000 kr
Crawl space with moisture problems	Mouldy smell from the hatch, dark or damp timber, condensation on plastic sheeting	100,000-400,000 kr
Basement with moisture problems	White salt efflorescence, damp patches, mouldy smell, flaking paint	100,000-350,000 kr
Inadequate ventilation	Ask for the OVK report, check whether windows were replaced without a ventilation upgrade	80,000-250,000 kr
Poor foundation insulation	Draughts at the skirting boards, low energy class	50,000-150,000 kr
Energy-hungry construction	Check the energy class (energiklass), ask for heating costs	Varies
Cracked chimney stack	Ask whether the chimney stack (murstock) is approved by the chimney sweep	Varies
Cast-iron drains	Ask whether relining or replacement has been done, and whether there have been blockages	Varies

A little orientation: crawl spaces (krypgrund) and basements (källare) from this period often lack modern drainage (dränering) and a moisture barrier, so damp can lead to mould and rot over time. Natural-draught ventilation (självdrag) built for leakier houses often works less well once a house has had new windows and added insulation. None of this is unusual, and all of it can be put right.

What you do

• Ask for the radon measurement report, and book your own long-term measurement if there is none.
• Treat all material from before 1982 as possible asbestos, especially if you plan to renovate.
• Look in the consumer unit for screw-in fuses, and ask when the wiring was last checked.
• Smell and look in the crawl space or basement for moisture and mould.
• Ask for the OVK report and the energy declaration (energideklaration).
• Bring an independent surveyor (besiktningsman) to look at the foundation, roof, wiring and moisture before you decide.