32.6% were households made up of just one person and 16 were adults who lived with their parents. Of the rest of the households, 578 were married couples without children, 642 were married couples with children, and 120 were single parents with a child or children. Thirty households were made up of unrelated people and 35 households were made up of some sort of institution or another collective housing. , 529 of a total of 968 inhabited buildings were single family homes (54.6%). There were 222 multifamily buildings (22.9%), along with 154 multipurpose buildings that were mostly used for housing (15.9%) and 63 other-use buildings (commercial or industrial) that also had some housing (6.5%). , a total of 1,934 apartments (84.7% of the total) were permanently occupied, while 208 apartments (9.1%) were seasonally occupied, and 141 apartments (6.2%) were empty. , the construction rate of new housing units was 5.4 new units per 1000 residents. The vacancy rate for the municipality, , was 0.18%. The historical population is given in the following chart: Heritage sites of national significance The Boscéaz (a Gallo-Roman villa), Orbe Castle with its two towers and plaza, the Swiss Reformed Church of Notre-Dame and the City Hall are listed as Swiss heritage site of national significance. The entire old town of Orbe is part of the Inventory of Swiss Heritage Sites. The Gallo-Roman villa is known for its Roman mosaics, which are composed of several hundreds of pieces on the floor of the original site. The villa was a palace belonging to a rich but unknown landowner. It was built around AD 160 and abandoned about 270. Nowadays, eight mosaics are still visible and can be visited. A ninth mosaic, discovered in 1993, is being restored and it is not open for public visits. Politics In the 2007 federal election, the most popular party was the SP, which received 26.68% of the vote. The next three most popular parties were the SVP (20.26%), the FDP (14.52%), and the Green Party (12.92%). In the federal election, a total of 1,107 votes were cast, and the voter turnout was 36.2%. Economy The town has a Nestle Research & Development factory with a working force of over 500 employees. The factory is responsible for producing Nescafé and Nespresso. The factory accounts for just over 15% of Nestlé's overall turnover per annum. The factory was opened in 1901 by Daniel