The documents you should have received with the ECA letter should have explained the situation.

In Vaud fire insurance is complusory for all households. You can choose to insure with any company (and if you do you'll be asked to provide proof of cover), you aren't forced to use the ECA.

As a renter the landlord should have insured the building but you still are obliged to insure for your contents,

The aid to compiling your insurance (from memory from when I arrived) was little more than a checklist to give you an idea how much to insure for.

The ECA cover is purely for Fire and natural disasters (mainly floods) so it doesn't benefit you for insurance against other damage to property.

The cost is pretty low as a result of this limited cover. I also vaguely remember there was a formula provided for the cost of the cover based om a value per 1000 of property.

The reason given for making it compulsory is so that other residents of the canton don't have to contribute to the costs of people who've just burned themselves out of a home - and seeing the number of buildings in our small region that went up in smoke over the last couple of years there might just be a tiny grain of truth there.

Or maybe the insurers don't investigate cause as thoroughly as they might:-)