How to shoot in-situ product videos in restricted locations?
Many people apart from construction workers need to visit building sites, so there are processes for that to safely happen. I used to have a job where we often shot in restricted locations like building sites and factories. It usually involved the producer contacting whoever controlled the site and asking permission, and then we usually had to go through the site induction process (so many induction videos, so, so many).

A few things to note: when you're on site be aware that you will probably wear out your welcome–most people don't realise how long it takes to shoot a video, they expect you to turn up, wave the camera around and go. So it's worth being clear to whoever is going to accompany you on site about how long you think the shoot will take.

Also be aware that the camera operator needs to have support people. If they're in a location like a building site there are lots of dangers around, and if they're focussed on the camera, they may not be fully aware of their surroundings. At the same time, you want to keep the crew to a minimum, so you don't have unnecessary stragglers wandering around.