New construction in Belgium: all you need to know

New construction is in Belgium the pivot of a unique legal, fiscal and energy ecosystem. Buying or having a new dwelling built is not just about choosing a plan and a plot: it means entering a very protective statutory warranty regime (Breyne Law, ten-year, two-year), a specific VAT regime (21% or 6% depending on the case), strict EPC requirements (mandatory Q-ZEN) and differentiated regional taxation. This guide lays the foundations for 2026, for anyone considering buying off-plan, turnkey or building new in Belgium.

Legal and fiscal definition of new construction

The term new build has no single definition in Belgian law: it depends on the subject matter. For VAT purposes, a building is new until 31 December of the second year following first occupation. During this period, the sale may be subject to VAT at 21% (often by the seller’s option, sometimes automatically for developers). Beyond that, the classic registration duty regime applies.

For the purposes of the Breyne Law of 9 July 1971, any contract relating to the construction, off-plan purchase or heavy conversion of a dwelling for residential use is concerned. The protections (security deposit, completion guarantee, double reception, mandatory mentions) apply as soon as the seller or contractor receives down payments before full completion. See Breyne Law explanation and scope.

For post-reception warranties (Civil Code), a work enters the ten-year regime from acceptance, i.e. provisional reception in practice. This is what makes the reception minutes so strategic.

The warranties that protect the buyer in new-build

Buying a new dwelling activates a staircase of warranties to know in order to activate them when the time comes:

• Breyne Law 5% security deposit: 5% of the price blocked at the notary or via bank guarantee during execution. See security deposit.
• Completion guarantee: if the developer goes bankrupt, the buyer recovers their investment or the works are completed. See completion guarantee.
• Warranty of perfect completion: 1 year after provisional reception, all reported visible defects must be lifted. See warranty of perfect completion.
• Two-year warranty: 2 years on separable equipment (heating, sanitary, electrics, ventilation). See two-year warranty.
• Ten-year liability: 10 years on structural strength and watertightness. Reinforced coverage since the 2017 Peeters law (mandatory insurance). See ten-year liability.

The whole is summarised on the pillar page construction warranties.

Taxation and EPC: the 2026 dual standard

On the VAT side, the new construction of an individual house remains taxed at 21% as a rule. Exception: the demolition-reconstruction of an old building benefits from a reduced rate of 6% until the end of 2026, subject to own occupation for a minimum of 5 years (habitable surface capped at 200 m²).

On the registration duties side on the land: 12.5% in Brussels, 12% in Wallonia (with “own and only home” abatement up to €40,000 of taxable base), 12% in Flanders. New construction on own land therefore cumulates registration duties on the land + 21% VAT on construction.

On the EPC side, the Q-ZEN threshold (Quasi Zero Energy Net) is mandatory in Brussels since 2015 and in Wallonia since 2021 for any new construction. In practice this requires: heat pump, double-flow ventilation, reinforced insulation, air-tightness verified by blower-door, and often photovoltaic. See EPC new-construction.

Case study: turnkey new house near Namur

File audited by the firm in 2024: buying couple, 4-frontage house 158 m², EPC A, near Namur, turnkey price €311,000 excl. VAT + land €86,000.

• Construction incl. VAT: €376,310 (excl. VAT + 21%)
• Registration duties on land (with abatement): €8,240
• Notary fees on land: €3,600
• Utility connections: €8,800
• EPC, controls, planning taxes: €4,600
• 5% security deposit blocked at the notary during execution: €15,550
• Exterior fittings: €16,000

Total cost price: €503,550 of which 86% in VAT + duties compared to an equivalent purchase of an existing property. In return, the household has: 10 years of ten-year liability, EPC A guaranteeing 20 years of energy savings, and the benefit of the Breyne Law security deposit throughout execution.

Pitfalls to avoid in new construction

• Paying a down payment before the security deposit: this is prohibited by the Breyne Law. Demand proof of the security deposit before any payment.
• Skipping the pre-reception: 3 to 5 weeks before delivery, a site visit allows defects still easily correctable to be reported.
• Rushing the provisional reception: it is what triggers the ten-year, two-year and perfect completion warranties. Allow 3 to 4 hours for a serious audit. See provisional reception checklist.
• Ignoring price revision clauses: Breyne Law Article 7 caps at 80% of fluctuation. Check the formula.
• Confusing “delivered” and “completed”: commercial delivery is not provisional reception in the legal sense.

Securing a new construction project

Buying or having a new build built commits considerable sums (€350,000 to €700,000 on average all-inclusive). Expert support ideally intervenes at three moments: (1) before signing to audit contract and specifications, (2) before provisional reception to prepare pre-reception and the checklist, (3) after reception to follow up the lifting of reservations and activate warranties if necessary.

Request a free quote or consult our Breyne Law support. The firm Mon Etat Des Lieux follows each file from contract reading to the lifting of reservations, with recognised expertise in the Brussels, Walloon and Flemish markets.