Almost everyone else has mentioned the most basic stuff (conduit, etc) so I'll add some of the less-thought of stuff.

Also run conduit to a gang box (with a blank faceplace) in the ceiling of every room (tucked into a corner). It'll be useful if you ever want to put in cameras, sensors, wireless access points, etc. A well supported electrical box in every ceiling is also good, even if unused for now, for future lighting or ceiling fan purposes.

Install weatherproof outlets (possibly with conduit nearby) under the roof eaves on the outside. It makes it much easier to install security cameras or plug in christmas lights.

If you're building your house with standard framing techniques, consider getting pest control tubing installed. It allows a company to come by every year or two and quickly spray insecticide within the walls using high-pressure air.

If you're not stuck on standard framing, consider using better building materials: https://en.wikipedia.org/wiki/Structural_insulated_panel

Spend the extra money to not just get a wired fire alarm system but a fire suppression system like commercial buildings or apartments are now required to have.

You might not have solar panels now, but it doesn't hurt to have the conduit running to the part of the roof that you might want them. It would make things much easier later.

If you're going to have a basement, get a sump pump set up even if you have excellent drainage. If there is ever some kind of crazy storm or bust pipe, it'll help pump the water out before it collects or gets too deep.

Install twice as many plugs as you think you might need. Consider quad plugs instead of dual plugs in some areas so you can avoid ever having to use power strips. In every room, have one plug that's wired separately than the others so if you ever want to set up a centralized UPS or have the cutoff switches for a generator, you can wire it to those plugs.

Some people rave about how awesome it is to have a central vacuum system with tubing throughout the house. I've never had it so I don't know, but I can see how it would be awesome for vacuuming staircases.

Install wired "water alarms" underneath your sinks, water heating system, under tubs, showers, etc. Water kills houses and you want early alerts. It's also not a bad idea to have floor drains in the bathrooms so if there is ever a major water leak incident, the water will drain right away rather than leave that room.

Speaking of water heaters, get an on-demand tankless gas water heater. It's more energy efficient than a water heater with a tank and it lasts a lot longer.

Consider climate change and design your house for extremes in your region plus a bunch more. Highest temp is 100? Plan for 120. Lowest temp is -10F? Plan for -30F. Strongest storms have 50mph winds? Plan for 75mph.

It doesn't matter if you're not at the coast, use hurricane straps to secure the roof rafters to the walls. It doesn't matter if you're in a forest, plan for wildfires by not having brush right against the house and installing a few piped sprinkler heads on the roof to wet it down in case of flying embers.

It doesn't matter if you're not in the desert or in Canada. Get a well-insulated roof that can handle 120F+ heat or the coldest winters. Use roofing material that'll hold up against major hail or flying debris.

Don't skimp on windows. You'll have them for 50+ years so get the best ones you can. They can cost a fortune, but the difference in price will be paid for 10x over in energy savings. Double/Triple panes, infrared blocking coatings, etc.

Also get emergency storm shutters built to size and the mounts/latches so you can securely attach a shutter in a minute or two by yourself. They don't have to be fancy or look good, just have good handles on them so you can maneuver them, hook them to something over the window, and latch them in place.

For solar panels, if you have the room, consider keeping your array on the ground level so you can easily clean them off or cover them. If you do put them on the roof, consider having a roof type where you have a small flat walkway built into the roof shape (or low slopes in some areas) so you can walk around them easily for maintenance. Too many home owners fall off their roofs.

Make sure that one or two rooms have exterior entrances and private bathrooms so you can rent them out or give the family member some extra privacy.