Demand for duplexes has kept up with supply and then some.

Supply and DemandIn real estate, prices and rents are determined by the imbalance between the number of buyers and sellers.When there are more sellers than buyers, prices decline until there is a rough balance between the number of buyers and sellers.When the number of buyers exceeds the number of sellers, prices increase until there is a rough balance between the number of buyers and sellers.Rents follow prices.Higher prices reduce the number of people who can purchase, increasing demand for rental properties and increasing rents.Lower prices enable more people to purchase, decreasing demand for rental properties and decreasing rents.What determines demand?

This will supply your base info.  

It is much more challenging to create supply in the Northeast further increasing demand.

When i asked about the property concentration in Fund 3 versus the other two funds they mentioned that it was due to the low market supply for what they were looking for. 

That is how AC can make a house 76d when it is 116d outside.B) Yes, when the average global climate temps rise, it will be more difficult to cool the average home....and conversely, when the global temps drop (which they do in a cyclic manner over the millenia) future AC systems will have an easier time of it :-)

I stay away from secondhand and thrift places, and make friends with contractors that get huge discounts at supply stores (sherwin williams, plumbing wholesale) Sometimes buying in bulk and selling what you don't need is a great way to meet people doing the same thing as you. 

So, as an investor is making an offer through a Real Estate agent/Broker using OPM, what type of verification and verbiage do you supply to the seller to show your ability to buy?

You might find this 20 minute read and breakdown of supply, demand, interest rates, and relative regional pressures on multifamily https://www.biggerpockets.com/blog/multifamily-crash-to-cont...

Admittedly, this is not standard, and when installers arrived they said they can't and won't do it)Supplies not arriving on time and impacting scheduling.