He's a very friendly host and speaks both English and French. It's on the 3rd floor of a charming little building. You have to climb your way up using the stairs, which is a common thing in Europe.
His place is a loft with an extra private bedroom (no locks). Dominique sleeps and works in the main area (living room + kitchen), and you sleep in the private bedroom. There is a single bathroom in the apartment, which is shared between the host and the guest.
The living room / kitchen area is not available for the guest.
From 10am to 4pm I intended to work from the private bedroom (it does not have a desk) but Dominique kindly asked me to go work from a café instead, due to heating costs and privacy. I'll ask AirBnb hosts next time to be sure.
I felt very safe walking alone even at night in Elsene (Ixelles) and around the city center, which is a 25-minute walk. I don't recommend the Brussels-North Station (FlixBus) area at night, though.
Great stay, good cost-benefit. I'd stay again.