What to specify for 10G Ethernet installation for new building?

I'm buying a house which I intend to live in for a couple of decades. The house is not complete yet, so now is a good time to specify modifications. It looks to me like it's worthwhile to wire the house for 10G Ethernet (I am reasonably sure that none of the cable runs will need to be more than 55m, but in any case I'll probably go for Cat 6a in preference to Cat 6). It looks like the cost-effective way to do this is to ask the builder to to it (I assume they will subcontract the work) before the house is plastered. I would plan for a patch panel in the loft space (and clearly, also power for a switch there).

I would like to make sure that I specify the things I need to specify to make sure I end up with a working installation. Apart from numbers and locations of Ethernet jacks, what else should I specify to the builder to make sure the result is useful?

(Anticipating the "why the hell 10G" question, I expect to live there perhaps 20 years; 20 years ago, Fast Ethernet (100 Mbit) had not yet been introduced. So that's a change of x1000 in speed in 20 years. So in 20 years 10G won't seem so much like overkill. Besides, I think the cost difference is reasonably small, except for the switch, but I'll start with a 1G switch).

Most likely the current standard for 10G will change for residential networking over the next several years. Currently 10G is found in datacenters, network bridges, and offices. I would recommend a different route where you're able to pull the wiring currently installed down the road.

The hardest part in homes is to do the initial wiring on a completed house. I ran straight down from my second floor to the basement. It took me all weekend. However, once a new standard for residential networking is done, I will upgrade the original Cat 5e 350MHz to something else. It would take me an hour to fish the new lines for the whole house since I already have the hanging wires there.

So, I would wait. Go with Cat 6 or Cat 5e 350MHz (both capable of running a 1Gbps speed). When running the cables, make sure that they are not stapled down or stuck around a bend. You'll want to tie your new cable to the existing one and just pull the old ones out (while running the new ones at the same time). If your house is yet to be finished (drywall not up yet) then this would be a good time to either run the wires yourself, or get some PVC tubing and run the wires through there.

You'll shoot yourself in the foot later if you find a 10G wiring, only to find that the residential standard for such speeds are fibre optic.