I just had my basement renovated and as soon as my washroom downstairs was completed have noticed a loss of water pressure and heat in the upstairs toilets. Both in the shower and sinks. Just wondering what could be causing this?

have noticed a loss of water pressure and heat in the upstairs toilets. Both in the shower and sinks. The pressure loss could be explained by minerals built up in the pipe walls being disturbed and clogging inlet ports and aerators but the hot water in the toilets tells me there's a crossconnection in the new section.
Get the plumber back to check and repipe the mistake. That should be your first concern. At the same time have hime flush out the lines and faucets to get your pressure back. Good luck, Tom

Tom, I think hchamb is calling the bathrooms, "toilets" and he has lost "water pressure and heat" to the bathroom shower and sinks... ;) He certainly couldn't notice a loss of heat in the upstairs toilet.. would mean there was hot water there to begin with!

My thoughts, much like yours, Tom, is that the system wasn't flushed out and needs to be cleared.

I also think the mixing valve at one of the new single handle valve(s) could be defective... maybe? Or, it could be a coincidence and an older mixing valve could be defective... but doubting that right now.

Another idea is that the shutoffs going to this bathroom could have been closed off for some reason and not fully opened back up again.

As Tom said, the plumber needs to come back and check this out.

Anyway, hchamb, let us know if you are around and want to discuss, OK?

Mark