I do not want old single pane windows in my properties either.

If your current windows are aluminum framed and/or single pane, then replacing with energy efficient windows can sometimes be cost effective (pay for themselves in energy savings in less than 7 years = 10 % ROI).

You get better terms on a primary residence -- lower interest rate, lower down payment requirements -- because if you encounter financial strain, you're most likely to pay the mortgage on the roof over your head.

Or did this strain the relationship?

Forcing rental rates up, even though affordability is already strained, supply-demand will rule. 

His view is that this not very passive and a strain for him.  

The studies I looked at comparing old to new and single pane to double pane-not done by window companies-suggested little or no return from all that effort and money.

“We are also expanding non-traditional offerings that won’t strain our facilities’ needs, such as online, hybrid, dual enrollment and flexible scheduling options.”She said the community, as a whole, values and supports education, helping to retain the district as one of the top-performing in the state and nation in the face of growth.The fastest growing county in the U.S. from 2014 to ’15 was McKenzie County, N.D., which grew 16.7 percent to a population of 12,826.Forsyth’s population total is smaller than only one county growing faster: Fort Bend, Texas, which grew 4.3 percent to reach an estimated 716,087 people.Other Georgia counties that ranked in the top 100 include: Bryan County at 22nd (3.6 percent); Columbia County at 28th (3.4 percent); Long County at 39th (3.2 percent); Effingham County at 51st (3 percent); Barrow County at 53rd (3 percent); Clarke County at 80th (2.6 percent); Fannin County at 93rd (2.5 percent); and Jackson County at 96th (2.4 percent).All population estimates are for counties with 10,000 or more people.Source: http://www.forsythnews.com/section/2/article/29791...

But you won't know the condition of the rest of the house wiring until that main panel is in and working.

The headaches and strains having a high mortgage at this interest rate.