[6] The Minister of Justice, Vincent Van Quickenborne, described Haren Prison as "a prison village, which will not only promote a new perspective on detention, with new functions such as that of security assistant and detention supervisor, but which is also more humane and fully focused on the empowerment and reintegration of detainees".

[10] Each cell has its own toilet,[9] a shower area where hot water is available twice for 5 minutes a day,[12] a television that can receive four channels (RTBF, VRT, Euronews and Eurosport), a radio-alarm clock, a microwave oven, a small refrigerator,[12][13] and a telephone.

A "Ducpétiaux" prison had wing-shaped cell complexes controlled by a central supervisory core.

"Ducpétiaux" cell complexes generally consisted of an open gallery with a maximum of three floors.

)[10] The prison is designed to be environmentally friendly, and has received the BREEAM "very good" certificate.

[1][6] Some of the buildings have green rooves [gross area 22,500 m2 (5.6 acres) including pathways].

[6] Nevertheless, a journalist (Arnaud Gabriel) who was locked up in the prison for 36 hours complained about the noises that he could hear when he was locked in his cell: "the constant blower that stays in the head; the fridge that gets started; doors opening; prison officers' shoes on the stairs.

[1][5] The Belgian Directorate of Buildings [fr; nl] acted as client for the design and construction phase of the project.

[6] "Cafasso NV is composed of three shareholders: Macquarie Corporate Holdings PTY Limited, FCC Construcción S.A. and DENYS N.V."[18] Denys NV is the main partner in the consortium, and is responsible for the 382 million euro construction cost,[c] the construction risk, and financing of the project.

[1] The buildings were designed by EGM architects, who collaborated with B2Ai on the prison village layout.

[5] "Macquarie Capital acted as sole financial adviser and majority sponsor on this project leading two debt financing competitions over a five-year period.

"[19] The state will pay an annual fee of 40.2 million euros for 25 years from the opening of the prison until 2047.

[1] Appeals were lodged against both the planning permission and the environmental permit issued by the Brussels Region.

[21] Objectors said that the project would generate an ecological problem; they objected to its large size; they said that its distance from the centre of the Brussels would increase in the isolation of prisoners from their families and loved ones; they said that it would cause very many journeys by inmates, relatives and justice professionals; they said that it was extremely expensive and therefore risked putting a greater strain on the justice budget.

Gilles Geenen explained: "In addition to the foundations, the cellars and corridors that connect the various buildings underground were poured on site because they must be watertight.

[9] As of December 2020, there were 500 people and 15 tower cranes working on the site, and on some days 100 loads of construction materials arrived, which made the managing the project a challenge.

[13] Originally, it was planned to start moving inmates into Haren Prison in mid-October 2022, but this had to be postponed.

In November 2022, FPS Justice started the process of recruiting 121 new prison officers [accompagnateurs de détention] and 52 security guards [assistants de sécurité]; candidates must either have Belgian nationality or that of a country in the Schengen Area, and must speak either perfect French or Dutch.