When moving to a new country the first thing to deal with is the difference in the laws. Traffic law is usually the first one: when you rent a car and drive of the airport parking lot. Yours truly has come to find out that usually police officers don’t respond when you tell them you were not aware of the law that you didn’t adhere to. The response: it’s the law… 
Funny story: my husband was pardoned the first time he visited CA: when he drove from SF Airport to Cupertino and a police officer stopped him and found out he came straight from Netherlands he was warned that speed limits in CA are lower than in Netherlands and he could not drive that fast ;))) he got of with a warning, promising he would drive slower ;))… When we finally moved to CA we both had to get used to the speed limits here…
With that said: There is a new law that affects everyone who lives in a home in California. Per July 2011 every home in California needs to be equipped with a Carbon Monoxide detector. This is next to the smoke detector every house needs to have. 
Reason: The Carbon Monoxide Poisoning Prevention Act of 2010 signed into law last year. Locally in Sonoma County, not having one could result in a $200,00 fine. Here is a link to the article in our local new paper the PressDemocrat this week.
There are more and more laws to comply with when you buy and sell Real Estate. They are part of the many disclosures your receive. Both sellers and buyers are always advised to read all the paperwork carefully.
The local hardware store is a great source for these new Carbon Monoxide filters. Home Depot has instructions on their website on how to choose and instal one that is right for your home.
Have a great week,
Mirjam