What do I do?!?! - Tenants installed kitchen in basement!!

[Tomiko Graves]

Hi all!

I need some advice.  This has never happened to me before and I'm not sure how to handle it.  When I went today to have my current tenants sign another one-year lease, I did an inspection of the property.   To my surprise, they built a kitchen (electric stove, sink and refrigerator) in the downstairs wash room.  

When I asked where the washer and dryer was, he said upstairs.  They had redirected the plumbing and electrical and installed the washer and dryer upstairs!!

Now, I'm no dummy.  Clearly, if you are installing a kitchen/kitchenette in the basement you have plans to move someone in (not on the lease).  That's actually the least of my concerns.  I'm concerned that if something happens to the property (electrical fire, flooding, ...) as a result of these new installations, I will be left S.O.L.

What are my steps to protect myself and my property?  I'm thinking step one is to get someone out to ensure the work is up to code AT THEIR EXPENSE...Please help!

*Also, I don't want to evict them because I'm getting top rent for the area and they always pay on time...through covid and all...