Luxury homes are not a new feature in real estate; you can find luxury estates that were originally built decades and even centuries ago (albeit ones that have been heavily updated and upgraded). But that means that as you search for a luxury home to purchase, you don't have to look only at new builds if you don't want to — you can seek out older properties.
No Whole-House Warranty, But Would You Need One?
If you look at an older luxury home, that structure most likely isn't going to have a builder's warranty covering it. However, anything that's been updated or replaced recently may still have a warranty, which could be all you need. Warranties help remove the financial sting of things that go wrong (because even if you can afford a luxury home, who wants to shell out for massive repairs). If you've fallen in love with an older home, the pre-purchase home inspection is going to be crucial.
The Electrical System
A new luxury home will have wiring and outlets that are modern and built to handle everything modern life can throw at them. In a luxury home, you shouldn't have to worry about whether you're exceeding a circuit's power rating. Any older luxury home you look at, even one from just a couple of decades ago, needs to have updated wiring and power supplies. Look at the circuit breaker box and see what outlets are available. Make sure the wiring will be up to your standards.
Bells and Whistles
Trends come and go, but they often leave their mark on houses. From built-in desks and workstations near kitchens to crown molding, each house is going to have those features that reflect what was trendy at the time it was built. Sometimes these features can be useful, like those workstations, but other times, you have no need for them. Look at what each house offers and decide whether these "unusable" features are ones you can ignore or replace, or if they'll continually remind you that you don't like them. That can help you decide whether an older or newer house would suit you better.
Sit down with a real estate agent to go over what each luxury home offers. You can see if an older or newer house might be better for you and what you'd need to do to get a specific house into the configuration that you want. You may find a gem that has literally withstood the test of time, or you could decide that the new luxury kid on the block is more your style.