Tenant Improvements Without Authorization

[Aspen P.]

We have tenants that have signed a four-year lease.  They've been somewhat high maintenance so far, with 1-2 maintenance requests every month since they moved in three months ago, but so far they have been reasonable and actual maintenance issues that are our responsibility to fix.

A few weeks ago they asked if they could paint an unheated utility room - the only room we never painted when we renovated the place after purchasing. I agreed and brought them a gallon of good quality exterior paint. I went over there this weekend to change the air filter and asked if I could see the paint job. It looks good, but in the process they also took out two older cabinets that were hanging on the wall and installed metal shelves. They claimed the cabinets were falling off the wall (they seemed secure last time we were working in that room), and stated that you know, they'd be there for four years, and were happy to leave the shelves when they go, but they could also take them down when they move if we wanted them to.

I also noticed that they've installed a few bookshelves in the house that are not freestanding but attach into the wall. I'm not crazy about them drilling into the walls and am especially not crazy about them throwing away cabinets without asking first (although the new shelves do look good).

Would you consider shelves/bookshelves that are attached to a wall falling under the normal wear and tear clause, that they have to remove and patch holes when they move, or are these more substantial improvements that they should be requesting approval for?

Our lease states "The Tenant is not permitted to paint, make any alterations, improvements, or additions to the Leased Premises without first obtaining the written permission of the Landlord. The Landlord's permission to a particular painting, alteration, improvement, or additional shall not be deemed as consent to future painting, alterations, improvements, or additions."

These tenants haven't been shy about submitting maintenance requests, and did ask about the paint, but I'm frustrated that they didn't then ask about the cabinets. I'd appreciate your suggestions on how to handle this situation.