My wife and I recently purchased a 40-year old home and doing some renovations. The home still has the original set of windows and looking install new ones. For those that did, what kind of energy savings did you see with a house full of new windows?

Do those renovations include sealing up any leaks and adding insulation? On a house that age you need to be sure that's good or the new windows aren't going to do enough to be worth it.

You likely won't see a huge difference in energy savings from just the windows. Certainly not enough to pay off the windows

What you do see is a big difference in comfort levels. No cold spots in the winter or hot spots in the summer. More even comfort across the house. Sound reduction is huge too, will be much quieter in the house.

Thank you for the responses so far. I'm searching for ways to bring down our energy bills, and I'm not afraid to invest some funds. However, I would like to start with a partial solution that will help the most initially.

I have seen other ideas like spray foaming the rafters or adding more insulation in the attic. I would welcome any suggestions that others may have.

I would check your home humidity levels too. If they are higher, I would also look into a whole home dehumidifier. Lower humidity allows you to not run the A/C as cold to be at the same comfort level.

Austin Architect study long ago was verified by an Aggieland Engineer.
Shading windows from the sun can result in energy savings equal to double the window's R-value - at least.
Many ways to shade ...

Most everyone in the biz will agree with more attic insulation - of ANY kind.

Venting attics not foamed very important = continuous Ridge & Soffit vents; gable vents have become controversial ... moneypit.com/

Ideal installation of a hi-SEER HVAC top-o-line always pays back.

Windows have always been a hole in yhour insulation but today, the glazing options - once limited to 1-2 "R" - can be 3-4, however controversial those options are in Central Texas.

Agree with humidity control IF your HVAC isn't doing it well enough.

Problem areas might be solved with mini-split HVACs

Shopping roof shingles' energy savings data or metal roofing savings acct for next time home insurance might help replace all that is good homework now.

West side tall evergreens or shade trees, esp. over a HVAC

Rural areas will cut a clear breeze path for the house to enjoy

An acre of greenery surrounding house = one ton AC in summer