I work in industrial construction in and around Belgium, offices, factory buildings and so on. Unfortunately I can’t help you with a small job in the Hague and I suspect that your job is too small + too far for our subcontractors.

I would ask the window system producers for contractors near you, try: https://www.schueco.com/nl/particulieren/raamsystemen And/or https://www.reynaers.nl/