Risks of buying a 1960s house in Sweden

The three things worth the most attention in a 1960s house are radon from blue concrete (blåbetong), damp in the foundation (a slab-on-ground or a crawl space) and asbestos in older building materials. An old house is not the same as a house in poor condition. Many 1960s houses are solidly built and have held up well. These are things to check calmly, not reasons to walk away. Once you know what to look for, most of it becomes manageable.

Radon from blue concrete

Blue concrete (blåbetong) is a blue-grey lightweight concrete made between 1929 and 1975, right through the period when many 1960s houses were built. The material has an elevated radium content that gives off radon gas, and that can raise indoor radon levels. It is most common in Stockholm, the Mälaren region, Gothenburg and Västerås, and affects roughly 400 000 Swedish homes.

The indoor reference level for radon is 200 Bq/m3 as an annual average. It is not a strict binding limit, but if the value sits above it, it should be brought down where that is possible and reasonable.

What to check:

• Ask for a radon measurement report (radonmätningsprotokoll). A proper long-term reading is taken during the heating season.
• Look for blue-grey lightweight concrete in the walls.
• Ask whether values above 200 Bq/m3 have been measured before.

Lowering the radon level with a radon sump or better ventilation often costs around 15 000-50 000 kr. Removing the blue concrete entirely is a bigger and more expensive job, but it is rarely needed.

Damp in the foundation

Houses from this era were often built with a slab-on-ground (platta på mark) or a crawl space (krypgrund), and both can hide damp. In a slab-on-ground with insulation laid on top of the concrete, a moisture trap can form where condensation and rot attack the timber sole plates. In a crawl space with poor ventilation, damp air condenses and can lead to mould and rot in the floor structure. These are well-documented moisture risks, but they are not always visible to the naked eye.

What to check:

• A chemical or sharp smell near skirting boards and floor trim.
• Floors that stay cold against the outer walls, or discolouration along the trim.
• In the crawl space: a musty smell from the hatch, dark or damp timber in the floor structure, condensation on the plastic sheeting.

Fixing damp in a slab tends to land in the order of 150 000-400 000 kr, and a crawl space often 100 000-400 000 kr. An inspector (besiktningsman) with a moisture meter gives you a far more reassuring answer than the eye alone.

Asbestos

Asbestos has been banned for use in Sweden since 1982, but it is often still present in houses built before then. It can sit in eternit roofs and facades, in floor tiles, in pipe bends and in tile grout. The key thing to know: asbestos that sits undisturbed is not dangerous in itself. It only becomes a problem when the material is worked on and dust is released, that is, during demolition or renovation. Treat any material from before 1982 as suspect until proven otherwise.

What to check:

• Eternit sheets on the facade or roof.
• Grey or black floor tiles of an older type.
• Older pipes with white insulation.

If you are going to renovate, asbestos must be removed by a licensed contractor with the right permit, and that usually costs in the order of 50 000-300 000 kr depending on the extent. If you do not plan to touch those parts, the cost can stay at zero for a long time.

Other risks to keep an eye on

Risk	What to check	Rough cost
PCB in sealant (around windows, doors, balconies)	Original sealant still in place, ask about a PCB inventory	30 000-150 000 kr
Ungrounded electrics	Plug fuses, two-pin sockets, no earth-fault breaker	50 000-200 000 kr
Flat roof with leak risk	Damp stains in the attic, poor roof drainage	150 000-500 000 kr
Inadequate ventilation	Ask for the OVK report, windows replaced without addressing ventilation	80 000-250 000 kr
Basement with damp problems	Salt efflorescence, damp stains, musty smell, flaking paint	100 000-350 000 kr
Copper pipes with corrosion risk	Ask whether the pipes have been replaced or relined	100 000-300 000 kr
Poor foundation insulation	Draughts at skirting boards, low energy class	50 000-150 000 kr
Energy-hungry construction	Check the energy class, ask for heating costs	varies
Chimney stack with cracks	Ask whether the stack has been approved by the chimney sweep	varies
Cast-iron drains	Ask about relining or replacement, whether there have been blockages	varies

One thing about PCB: the inventory and remediation requirement applies to larger properties, not ordinary houses owned by private people. PCB can still be in the sealant, but you have no legal obligation to inventory your own house.

What to do

• Ask the agent for the radon measurement report, the OVK report (ventilation inspection) and the energy declaration before the viewing.
• Bring your nose and eyes to the viewing: smell near skirting boards and in the crawl space or basement, feel for cold and damp surfaces.
• Ask plainly what has been dealt with: pipes, wiring, roof, drainage, radon.
• Hire an independent inspector, and ask for a moisture reading if the house has a slab-on-ground, crawl space or basement.
• Leave a buffer in your budget for anything you cannot fully resolve before the purchase, so the decisions feel calmer.