Oops built too high

I built a building on the ground then placed it in the sky at the max build height. I am now trying to place a roof on top of it, but the height restriction will not allow it.
Does anyone out there know it there are any tricks that can be employed to get around that as its gonna be a pain to lower the whole structure.

I do a lot of my building high in the sky. Fewer interruptions and lower lag at 700 M up.

If you moved the structure above 768 Meters, and it's incomplete, I assure you that you are better off moving it back down, before it falls apart! Structures above the 768 Meter limit are unstable. They might last a minute, a week, or a month, but one bump, and they can fall apart.

Ride a prim up to the overly high structure, select all of it at once, and move it back down below 768 Meters. If you really want to put the final structure above that altitude, make a backup copy of the build before you move it, so you can replace it when it inevitably self-destructs.

If you insist on leaving it in place, position a platform below it, at perhaps 725 Meters. You can go up to the overly high build, dragging prims with you and positioning those prims at the corners where you want the roof, then sending them back down to the platform height as guide posts for positioning the roof you plan to send up. Build the missing pieces on the paltform, and move them up.

Easiest way to start building something high in the sky? Make a 3M long prim, sit on one end of it, and ride that prim up to the desired height. You can rez other prims or objects from inventory on the end of the one you are sitting on.

My floor level is at 768 mtrs but the walls around it, would that be safe or is there a chance of having the said problem with the walls that go above 768 ?

thank you for your info Ceera, i decided to lower it all by 50 mtrs
All is well now

For safety's sake, none of the prims should extend above 768 Meters.

You should be fine, now that you lowered it.