Best flooring for kid's bedroom

[Lily7050]

We have finally got a builder who is going to start our house redecoration in January.
The builder prefers carpet flooring but I am not sure if carpet is good for DS bedroom. At the moment the room got an old carpet that I washed with Bissell a few times. I have to keep running an air purifier over nights as otherwise DS keeps coughing a lot. I am not sure what irritates him but he sleeps much better with the air purifier on.
DS has a mild eczema but no obvious allergies.
If we put a new carpet it would be a manmade so synthetic.
Do I have to wash the carpet once a week? Not sure it will last long then.
I was thinking of vinyl (Karndean or similar) but then read that vinyl has high VOC content.
Is it best to put the engineered wood? The room is quite small, about 9 square meters.

We have wood tile in our children’s rooms. It was actually an accident on the part of the builders (they were supposed to install engineered wood in those rooms), but it has turned out to be very practical. We use large rugs to make it warm and cozy, and they’re washable when they get dirty, so it’s much more hygienic than wall to wall carpet from an allergen perspective. The tile itself looks decent and is bulletproof, which is handy for a kids room.