Tenant wants to install tornado shelter

[Jim Bentley]

My tenant called, and they want to pay to install a tornado shelter (this is the kind that goes in the garage floor; only takes a couple of hours and costs around $2500). This is in Oklahoma, about 15 miles from where the big tornadoes hit last May. I was already contemplating getting one of these installed at my three houses, but hadn't mentioned it to them. The addition of a storm shelter will easily be worth $50/month in additional rent around here if they do leave.

They want to pay for it themselves and right now plan on staying in the house for several years. They are great tenants.

What is the best way to handle this? I know there can be legal problems if we get mad at each other later and they decide they want to leave but then decide that they want payment for 'their' shelter. I also know that I'll have to handle the permits.

A couple of options I'm thinking about:

1) Lowering their rent by $25/month, and having them sign a new 1 year contract at the new rate, along with a clause that states that they relinquish the shelter when they leave.

2) Or would it be better for me to pay to install the shelter myself, and raise their rent by $25?

After I wrote this, I'm leaning towards option 2. Would there be any issues with that?