I spent almost 20k in equipment for that gym.

We have a lot more capital access then people generally would think and we already have all the equipment and people to execute.

They may require the rental of some special equipment to get it done, but it certainly seems doable. 

No person may occupy a property during the term of a Temporary Access Certificate, but the owner shall be permitted to store equipment that is related to the proposed use or occupancy of the property or is needed to repair the substantial violations during the time of the Temporary Access Certificate.SUBSTANTIAL VIOLATION: A Substantial Violation is a condition which makes a building “unfit for habitation.”

For 20 years we just held there my father's construction tools and equipment.

It is good in a sense, I less worry about fire safety and it saved me about $8000-10000 to add full equipped kitchen and laundry on site.I have 1 bedroom in my basement, and for the entire basement, I have an independent entrance and a stair goes to upstairs.

Further, the solar panels and equipment, as well as all structures built by the tenant were to be considered fixtures and not real property, allowing the tenant the option of removing them.  

In the water industry we have equipment available to use that serves to identify leaks on mains, which is kind of what you're aiming for, but it's nowhere near cost effective for your application here.

You should also check on the age of the major mechanical equipments, roof,.....  

Am I well equipped enough to dive in?