If I was to purchase a multifamily investment, for example a 6-unit property, and turned two of the units into vacation or short term corporate rentals that increased NOI when compared to traditional rental income with lower NOI, how would lenders look into this in terms of a value add to the property?  

I usually do suggest finding a deal first as it increases the chances of landing a mentor, but I'd also say that finding a deal is the 1st step even without one.

Excited to browse all the topics.I started out as a retail General Contractor doing projects for customers.

Find good software, figure out how to do dynamic pricing/yield mgmt so you can show owners how you can increase income (price for max revenue in season, occupancy in off season), hire good housekeepers and make a good corny website.

In the end it will save you a lot of headaches and even increase value of the home in the future. 

While you are looking within that circle you are informing everyone that you are a real estate investor which increases your chances of getting deals.

I also own a farming business (www.HealthyHenFarms.com) with my wife and 6 kids where we produce and direct market organic, pasture raised chicken to our customers in the Raleigh area.I've dabbled in real estate off and on for 20 years, mainly turning primary residences into rentals as we have moved across the country (NC, CA, GA, VA) over the years. 

I suppose rent could be increased to account for the higher utility bills, but in general is there a general clause in a lease that you normally put in to disallow things such as the window air conditioner or other modifications to the unit.

These documents are always customized for the user?

I neither have the time nor inclination to spend very much of my time engaged on this or any other forum so often what I post is a short version of what I share with clients and customers.