And then the big question, what is the price for that? I suspect that for a bungalow like yours, a central ventilation system of the category "Wohnung" will be used. Questionable whether it is much more expensive.
Central ventilation system just under 9000 euros. The roller shutter system 4800, but only because roller shutters were already calculated electrically, otherwise more.
But I would really have a deep think about it. 4,000 is quite a bit of money, but a comparison for this rather "marginal" amount seems sensible to me. Weigh the pros and cons of both systems.