Around here many homes build in the 70's were done well since there is one particular builder who's still around who did quality work back then... you can tell it's one of their homes by the steel I-beams in the basement used to support the structure versus having wood.
late 60's to 70's are in the best part of town here and what I'm looking for. The old stuff doesn't really turn me on around here. Squeaky floors, some of the homes looked like they had major structural issues.. bowing basement walls, uneven floors, so many remodels over the years that they look ugly on the inside (that cheap wood panel stuff people use in finished basements and they use in mobile homes found everywhere.. hate that stuff)
Painting and Texturing Panel Walls | Mobile Home Repair
The new constructions.. well lots of them use fiber cement and I may be in the minority here but I don't like the way it looks, I don't like that it needs painting, I don't like how there are entire subdivisions with the stuff in it, and those subdivisions.. the driveways in them are starting to fall apart on some of the homes.
I look at the condition of the siding, to see if there's anything under it (tyvek, styrofoam), condition of the roof, eaves, flashing, gutters, get up into the attic to check for water, rotting, insulation. Check the pipes, open up the breaker box to make sure it's all copper, among other things. Look at unfinished areas of the basement for signs of water intrusion, check out the sump pump. Look at drainage issues, the slope of the property, condition of the furnace/AC, let the water run and check that it doesn't back up, and the list goes on. Aesthetic stuff like granite countertops, not only do I not care about but I don't want granite. Doors, paint, garage doors, all cheap items that can be fixed.. but a failing foundation or one with moisture issues.. more expensive, along with things like improperly maintained siding, etc.
Older houses give more bang for the buck and all the major issues have been fixed. I would not buy a new construction because why pay more money for less square footage, inferior construction quality, and less desirable location. My target are the late 60's to 70's homes, making sure there is no aluminum wiring of course. Mills construction never used it, from what I can tell. I've seen old fuse box breakers with a date stamp of 1971 and it's all copper behind them. Not all homes in this time period are perfect.. a good builder would not use particle board floor underlayment, it's another thing I look for. If these homes have not been insulated I can see how they might be even less energy efficient than older homes that used plaster, etc... however from what I've seen I prefer them to older stuff from the 40's and back.