Active cooling function heat pump or air conditioner in new construction

If the module (gross online price currently 900 EUR) is installed directly with the system, it should not cause significant labor costs. Retrofitting will. If the technician charges 3000 EUR, I would first try it this way (active) and possibly look for someone later to retrofit it. Ideally, only labor costs are charged if you procure it yourself (also better for tax purposes).