My wife and I recently closed on a quad and are planning on swapping out the old locks.

.**  The 90 degree right angle radiator valves were swapped out on many other radiators; this one was not modified. 

My idea was to have a lock box mounted on the side of my units and to swap out the codes if necessary if someone doesn’t work out or whatever may be the case.

Obviously there are a ton of books, podcasts, and material here on BP you will get recommended and can dive into...but a huge help especially if you're interested in the commercial and multifamily space is to go to in-person events such as meetups, conferences, and seminars.While material will be great, meeting and getting around other investors and like minded folks will help you find your investment philosophy, swap experiences, and get comfortable with where to start.

Reading BigPock books is how I found u-all and I am loving the board thus far.Tired of swapping 60 hours for dollars!

It's no different than me hiring ABC Plumbing to swap a water heater, minus the affiliated business relationship.That said, the services rendered by entity A for new entity B should be accounted for in the form of inclusive services... services need to be costed, warranted, insured, and held to the same standards you'd expect from a non-affiliated contractor. 

I'm actually transacting business with these folks I network with, not just swapping business cards and rubbing shoulders. 

If the building is large oversized freestanding radiators I'd highly consider swapping it out for a couple of wall mount boilers that are daisy chained together with outdoor temperature reset control. 2x reasons, it can modulate the temperature of heating water on mild days and if the demand is low it only needs to use 1 boiler.

If you have access to the FB SNA housing swap page, that's a pretty easy place to market your property as it is coming available.

She did tell me she sprays air freshener a lot so I'm just going to swap AC filters more often on that side.