Go to the supply houses--the ones that deal directly with contractors like plumbing supply, electrical supply, roofing, etc. 

@Osvaldo Cruz this is highly dependent on what market you are in, Desert southwest would be earth tones all the way, but since you said siding I'm guessing that isn't the case.PS your title could use some work because I thought I might have to come in here and school someone on fair housing regulations :)

@John Williams    If you'd be willing to look into the Fayetteville area, you'll find a steady supply of deals.

They're so integrated with their supply chain I'd always assumed they were their own landlord.

Either way the best way to scale is to systemize the process and let your contractors supply all materials and labor.

I’m talking about something that connects to your main water supply and either alerts you that you have a leak or takes the next step and shuts the water off for you.

Why on earth would you consider harming your asset to make life unpleasant for some freeloaders.   

That will eliminate those homes from the rental pool, which then lowers the supply and likely will raise rents further. - It may take a long time to get approved by HUD and may need $ thousands in upgrades to come up to HUDs requirements for some properties.

I subtract the KWh on the sub meter from unit 1’s electrical bill because unit 1’s panel supplies the electricity to it.

All we really have to do is paint, which supplies for that will be free due to my dad having a surplus.