Is it above the graft? Is there a graft? I would be very cross too, but I think there's hope. Roses are sooo tough. I'd prune to an eye if there is one, or at least make it a clean cut.
Anyway, someone with much more knowledge than me will answer you.
Good luck.

If they didn't cut below the graft as titan 1 said & if they didn't compact the soil with workers or equipment standing on the roots, you should have a pretty good chance of them coming back. May take several years, especially if they are a large bush or climber.

4 inches is sometimes what we have to cut ours back to after a severe winter. The roses will come back from that. Leave them alone except for water and wait to see new growth on them before you give them any fertilizer. They should bounce back but it will take them time to become the size they were so be patient.

Lots of water for a start, they will need that, then a light dose of liquid fertilizer be my rcommendation

I had the same thing happen here... Thought mine were gone forever...and then a month later I saw growth poking up thru the mulch. They have come back better than ever! And this was in the heat of August!

Skys the Limit dies to the ground every winter, then grows to 12' by August, only to die back again, every year.

Here around town I often see landscapers chopped down rose bushes to about 10 inches or shorter during their "fall cleanup." These are all landscape shrubs such as the Fairy, Knock-Out, Drift and the Flower Carpet. They do this year after year, and the roses seem fine.

did i mention...mine were at ground level and covered with mulch.

henrobinson - as well as water, the"leaving them alone" advice above is important. That means that you have to protect them from the builders damaging them further by stacking materials on their roots, trampling around them, etc - all of which will compact the soil and might kill them. I would recommend putting some sort of temporary fence around them - at least 3 feet away from the base of the roses. You will probably have to speak sternly to the builders - this is important.

When we had our 3 story house painted, & roof repaired & some walls re-shingled, we chopped the huge climbing roses down to about 6 feet & bagged them in burlap. However, they only survived because my DH talked with the contractors, and told them that it was worth his life (he blamed me, which was fine with me) if they trampled on the beds or touched those roses, or stacked stuff around them. He was here watching them every day (being a contractor himself, he was able to speak their language and schmooze them), and every time one of them stepped onto those beds, he was right there, pleading that they had to save him from spouse-acide by me. I cooked home made cookies for them every day, and between the two of us we saved the roses. It takes more than one conversation, and constant vigilance. Oh, and honey always works better than vinegar...

Jackie