In Sombreffe, 8,440 people live within a municipal area of 35.9 km². The average age is 39, and the population is 50.4% women. Home ownership stands at 78%, while average annual net income per capita is €18,889. The recorded nationalities are 95.5% Belgian, 1.3% French, 1.3% Italian, 0.5% Romanian, 0.3% Spanish, 0.2% Portuguese, 0.2% Cameroonian and 0.9% other. Across the local housing stock, homes average 6.4 rooms and buildings date on average from 1928.
Apartments are a small part of the housing mix: 6.3% of dwellings are in apartment buildings, compared with 93.7% in houses. The building categories comprise 40.3% open-type houses, farms and castles; 32.4% semi-closed houses; 17.5% closed-type houses; 6.1% buildings and flat blocks; 2.2% commercial houses; and 1.6% other types. There is 1 flat for sale. Its listed price is €250,000, which is also the current average price for a flat to buy.
The N29, N93, N98 and N273 provide road connections through the area. The nearest stated A15/E42 motorway entrance is 6 minutes by car from the town centre; the A54/E420 entrance is 13 minutes away. Public transport includes TEC bus 147a on the Gembloux–Fleurus–Tamines route, 247a between Gembloux, Corroy and Sombreffe, 347a between Gembloux, Saint-Martin, Tongrinne and Onoz, and express E5 from Nivelles to Namur. NMBS/SNCB line BUS is also listed, running between Tournai and Mouscron. Nearby stations listed are Ligny, Tilly, Mazy, Fleurus and Chapelle-Dieu.
There are 10 nurseries in the municipality, with Les Briquaillons and Carmita Calvo Ruisanchez among the named options. Sombreffe also has 10 nursery schools and 10 primary schools, including Ecole Fondamentale Autonome De Sombreffe - Les 2 Châtaigniers, Ecole Communale De Sombreffe and Ecole Fondamentale Libre Saint-Laurent. No secondary school is listed in the municipality. For groceries, there is 1 OKay and 1 Delhaize. Shared bicycles and shared cars are not available in Sombreffe, and no EV charging station is known there. Brussels South Charleroi Airport can be reached in 15 minutes by car or 97 minutes by public transport.