We have done 8 self storage locations and 2 country subdivisions selling lots in the Omaha area and been very successful.  

A huge number of properties we have looked at would have issues on this front.It can lead to an opportunity to improve the value of a property if you can buy it with an illegal area, get that area legalised and then sell on with a higher value that the bank would lend against, but it's not clear cut and it seems though that there are almost two levels of 'legalisation' - we were able to register all of the annex on the plans and could fully incorporate a portion of it but there is another portion that is too close to the back boundary wall that should only be used for things like storage and not ever for habitation. 2) During the purchase process be careful, amongst other issues with this property we had the situation where the seller's lawyer was not actually a lawyer (having been struck off).

Self storage zoning.1.  

Now the biggest impactor is often the least spoken on which is energy storage.

They do public debt funds, apartment complexes (in Southern California and the Southeast), car washes and self storage.

In my case, I have residential rentals in one LLC, commercial properties in another, self storage in a third, and my real estate company operates in a fourth.

@Henry Clark is an expert on Storage development maybe he could give some pointers.

Digitize physical receipts for easy storage and use a consistent naming convention for easy sorting - 2024.03.25 Home Depot.Maintain proper records, such as contracts, settlement statements, and promissory notes.Additionally, you can track income and expenses consistently using software or spreadsheets.As you scale, if bookkeeping isn't fun, consider hiring a bookkeeper for a couple hundred bucks per month.

At some point the House wins.To put it in Self storage terms, very similar to my C market comment above.

It also sits on 2 acres with separate buildings for animals and a nice storage shed.