Multi-Family -- Security, Doors, Access

[Michael S.]

I own a 10 unit building which has 3 separate entrances/common areas with have mailboxes, stairwell, etc.  Two entrances have 4 units each and the 3rd entrance is for the 2 smaller apartments.  It's also on a somewhat busy road downtown. It currently has exterior doors from the street that don't lock, which allows anyone to come and go as they please.   Occasionally we have homeless people living in the basement and limited security to the tenants.  The doors are damaged and need replaced anyway.  

I'm in the process of taking over the management on my building and want to outfit the location w/ new doors, security, monitoring, doorbells, etc.   I was thinking something along the lines of a Ring system, coded entry knobs, and a few cameras up high on the corners of the building also.  

Any recommendations on a good system here?  Thanks!