Earthquakes in Switzerland are a threat which should be taken seriously. Although these can cause enormous damage, at this time they are only partially covered - and only after taking off a deductible of 10 per cent of the insured amount. Mortgages are not secured at all.
Pools available in many cantons
In most cantons, the government-run building insurance agencies have a pool for earthquake insurance which would voluntarily pay out a maximum of CHF 2 billion. Consider, however, that the current value of all buildings totals CHF 1600 billion.
The Canton of Zurich is well covered
The situation is different in the Canton of Zurich. There buildings are insured against earthquakes automatically and at this time without any surcharge through the Cantonal Building Insurance Agency. This is indeed limited, but nonetheless the Cantonal Building Insurance Agency at this time has at its disposal 2 x CHF 1 billion annually for 2 x 1 earthquakes, and that just for the Canton of Zurich.
Unsolved problem in many cantons
Not counting the government monopoly, at the end of 2010 private insurers in the cantons of Geneva, Uri, Schwyz, Ticino, Appenzell Innerrhoden, Valais und Obwalden had still made available voluntary maximum coverage of CHF 200 million. This, however, has now been withdrawn because the pool just mentioned has been disbanded.
Consider (additional) earthquake insurance
Clearly that the amount of money set aside is insufficient for a strong earthquake. That's why insurance companies such as Allianz, Generali, Nationale, Lloyds, etc. offer coverage in all cantons. It pays off to compare them.