Very stiff new UVPC sash windows

[Thisoldheartofmine]

Probably panicking unnecessarily as the installers are due back today to finish job.
I rushed round when they left yesterday and could barely shift them.In fact couldn't shift one and son had to oblige.
Obviously I'll talk to them ,but is this is a thing ?
Have I made a poor choice of style ?Could they be badly fitted ?
I was so excited and now feeling

Depending on the glass chosen they can be heavy. The one in our office we had fitted was very stiff, we called the installers back who came armed with a can of silicone spray and it's still a little heavy but no longer stuff. I was surprised at the difference it made.

All the uPVC sashes we have had have been really difficult to move.

Thanks both. I think it's just the way they are . The guys installing them push them up and down and say no problem
But I'm short and in my 70s so it is a problem.
I'll try the silicone spray

We inherited upvc sash windows and they are fine to open/close.

Hopefully your windows will get easier with use/age.

The guy in the office did say they would ease the more they were used.
But I wasn't sure if he was spinning me a line.
But good to hear confirmation.