It seems like there isn't enough money in the first level + hideout to get you to the construction site. So I just had to constantly load the office level and return to the hideout to get that +100 cash each time for the last 500 I needed. Made it to the end of the construction level but sadly didn't find the exit to get back out and into the hideout :(
Viewing post in The Louvre Heist jam comments
Thanks for playing.
There are more than money packs to pick up in the office and they make it os you get above the 10k needed.
Returning to the hieout shouldnt respawn the money so that is a bug I need to look into.
The Briefings for the buildsite tell you what the goal is for the area. There isnt a "normal" exit from it.