ᐅ Prices excessively high for ventilation system and electric aluminum roller shutters (roller blinds).

Hello, we have received what we consider a quite good house construction offer from a developer for a single-family home with 161m² (1,733 sq ft) of living space. However, we are puzzled by three items that seem completely overpriced to us:

- Installation of a central comfort ventilation system in the utility room, brand: Zehnder “ComfoAIR Q350 TR,” with highly efficient heat recovery for €17,300

- Cladding of the main building up to the eaves height, with the gable of the pitched roof remaining plastered, for €19,900 (would brick slips be cheaper to apply afterward?)

- Installation of a lifting/sliding door (brand: Rehau 80 Synego or equivalent, 5-chamber system with steel reinforcement) instead of the standard patio door element, approximately 2.76 x 2.32m (9.1 x 7.6 ft), for €4,120

- Installation of a total of 19 aluminum roller shutters (three of which are wider in the living-dining area) with electric roller shutter motors, color freely selectable, for a total of €23,190

Do you see any potential to save here? Is it possible to contract the above work separately? What have you paid for similar items?

Thank you and best regards