To the best of my knowledge, there was no government edict that commanded the private sector to do this, nor was the government subsidizing any of this private sector MBS activity if a quota was met.

This presents an opportunity for investors, as a house with an effective filtration system will attract and keep tenants and potentially command a higher selling price with fewer days on market. 

I have an acquaintance who recently constructed a new 16 (maybe 18)-unit student building all two bedroom/two bathroom and he's not commanding any significant  amount of additional rent.

Where they are ubiquitous, they may have difficulty commanding good premiums, but on the other hand they are readily accepted.

If there are special circumstances, say with a small local lender, other things might be arranged, the Realtor should be aware of that.They probably seem unconcerned as they are speaking to someone they probably feel like doesn't command knowledge beyond thiers, knowing too that in such short fuse circumstances a payoff is what works, not some further financing arrangement.

He has the money, but not the time, as he owns several businesses that command all of his time.

Est 233 ,, divide by 4 = about 58 each.. hard to compare the duplex you didn't include price,, so ya do the math but personally I put my efforts towards the 4 plex.Honestly if the guy is 100% rented and his rents are close to market you can figure the interiors command that price and are probably pretty decent.YOu can start this property and do very little until you have a vacancy, and then decide what you want to rehab, otherwise  your set, and can do some exterior, yard and common area fixes first which will attract and warrant rent increases to current units.

He also receives free health care for his spouse and child as well as support given from most commands to help with a first child for example, breast pumps, bottles, etc provided by tricare.

Owners who prioritize energy efficiency and lack of turnover- sustainability in all senses of the word, have a long view. 2) These upgrades may very well allow you to command higher rent.3) It is landlords with attitudes who care most about collecting money from their tenants who make for the almost universal animosity between tenant and landlord.

At the same time, they don't offer the economies of scale bigger complexes command.