We live in Tervuren, which isn't really a Brit ghetto - it's just that a lot of the Brits who work at the EU (like my dh) and the large four lettered international HQ in Evere get houses here as it's near the British School. Most of us have Flemish landlords and Flemish neighbours.
DH lived in Evere before I moved out here. It's nice, but quiet, and we had to walk about 15-20 minutes to the nearest tram from where he lived.
Tervuren is nice and green; has a great park and the arboretum for walks/cycling. The British school contacts group has a lot going on for newcomers to help them settle and organises trips as well.
DS is at the British school as that's where dh's employer pays the fees. As dh is only at the EU for 3 years and then may return to work in Evere again, or we may be sent back to the UK, it seemed sensible to keep him in the UK system, so that he can slot straight in to year 10 if we go back.
I've been here two years and really enjoy it - the weather is just like Cornwall only slightly more chilly; I can see sheep in a field at the back of the house; there are 5 chocolate shops within cycling distance and the beer is good.
Depending where you are working in Evere and where you live, you may have to drive in to work. DH could not have done the Tervuren - Evere commute without a car. Now he works at the EU he trams and metros in each day, unless Amazon are delivering that day, when he needs the car to get it all home.
A 4 bed house with garden along my road was being offered for rent for ?1500 the other day; my place is about ?2100 per month (but we don't pay anything like that as dh's employer pays that, and we pay them a cheaper rate.)
Hope that helps.