EPC of a new construction in Belgium: what to know

The EPC of new construction has become, since 2014 in Wallonia and earlier still in Brussels and Flanders, the regulatory and economic centrepiece of any new construction project in Belgium. Everything is aligned to it: architectural design, choice of materials, joinery performance, sizing of heating and ventilation systems, and even eligibility for regional grants and fiscal advantages. For a buyer or a client, understanding the 2026 EPC requirements and the financial implications of the targeted label is no longer optional: it is the condition for a compliant, valuable project compatible with future 2030 standards.

The EPC: legal framework and 2026 objectives

The Energy Performance of Buildings is framed by a European directive (recast in 2018, updated 2024) transposed differently in the three Belgian regions. In the Walloon Region, the decree of 28 November 2013 and its implementing orders; in Brussels, the ordinance of 2 May 2013 (COBRACE); in Flanders, the decree of 13 July 2012. Each region defines its thresholds, calculation method and sanctions.

The unifying 2026 objective is the NZEB (Nearly Zero Energy Building): any new dwelling must consume very little energy, and what remains must come mostly from renewable sources. Concretely, in Wallonia for a 2026 permit:

• K-level ≤ 35 (compactness envelope insulation).
• E-level ≤ E45 (total primary consumption).
• Espec ≤ 85 kWh/m².year (net energy need).
• Air-tightness ≤ 6 m³/h.m² under 50 Pa.
• Minimum renewable share (photovoltaic, heat pump, solar thermal).

In the Brussels Region, similar requirements with the Passive standard gradually extended. In Flanders, minimum label E30 from 2025 for new permits.

These thresholds correspond in practice to a minimum EPC label A, sometimes A+ depending on the technical choices made.

EPC labels: from G to A+++

EPC labels range in Belgium from G (very energy-intensive) to A+++ (excellence) depending on primary energy consumption in kWh per m² and per year. In 2026 new-build:

• A+++: < 0 kWh/m².year (net energy-producing building, rare).
• A++: 0 to 45 kWh/m².year (passive or near-passive).
• A+: 45 to 85 kWh/m².year (very high-performance standard).
• A: 85 to 170 kWh/m².year (minimum regulatory threshold 2026 in most cases).
• B: 170 to 255 kWh/m².year (underperforming in new-build, non-compliant).

Targeting A+ or A++ rather than strict A typically costs 5 to 10% more on the construction budget (better insulation, generalised triple glazing, high-performance heat pump, photovoltaic) but offers:

• Annual energy charges divided by 2 to 3 compared to A.
• Resale capital gain estimated at 4-7% of the price.
• Access to maximum regional grants.
• Regulatory durability: compatibility with 2030 standards and beyond.

Calculation method and EPC certificate

The official EPC calculation method is codified by an accredited software fed by an EPC officer designated at the start of the project (often the architect or a certified design office). The calculation integrates dozens of parameters: building compactness, glazed surface per orientation, type and thickness of insulation per wall, thermal bridges, boiler or heat pump efficiency, ventilation flow, measured air-tightness.

The final EPC certificate is issued after reception of the building, on the basis of the elements actually executed — not of the declared project. Any difference between planned and executed (thinner insulation, single-glazed window substituted, sealing defect) degrades the final label and may lead to:

• Administrative fines (Wallonia: up to €50/m² × floor area).
• Non-delivery of occupancy permit.
• Refusal of final connection by the network operator.
• Retroactive regularisation of 6% VAT in case of demolition-reconstruction.

Hence the importance of an EPC audit at reception, checking that real performance matches the declared performance. See provisional reception for the overall process.

Economic impact: grants, taxation, resale

The EPC label now conditions access to many regional grants. In Wallonia, the Walloon energy grants portal documents:

• Heat pump grant: €1,500 to €6,000 depending on performance and type (air-water, geothermal).
• Double-flow ventilation grant: €1,000 to €2,500.
• Photovoltaic grant: variable according to power.
• EPC A+ and A++ bonus: 10 to 30% increase on all grants.

In Brussels, Renolution energy grants with similar scales. On the taxation side: the 6% VAT for demolition-reconstruction (see VAT 6 conditions) is subject to strict EPC conditions, and reduced registration duties sometimes depend on the label achieved at resale.

On the resale side, Belgian property studies 2024-2025 show a gap of 8 to 15% between an EPC A++ property and an equivalent EPC C property, at identical surface and location. This gap widens each year with buyer awareness of energy charges. See new-build fiscal advantages for the overview.

Pitfalls to avoid on the EPC of new-construction

• Believing that the declared EPC = actual EPC: only the post-reception certificate is authoritative.
• Substituting during works without recalculating: a change of joinery, insulation or system can degrade the label.
• Neglecting air-tightness: a failed blower-door test can lose a whole class.
• Undersizing the heat pump: insufficient winter performance, very expensive electric backup.
• Oversizing the photovoltaic: additional cost not amortised if resold within 5 years.
• Confusing EPC and acoustics: these are two separate regulations, to be checked separately.

Securing your EPC project

Before signing the contract, request an EPC specifications audit: coherence of technical choices, sizing, supplier technical sheets. At reception, check the final EPC certificate and any deviation from the declared project. The firm Mon Etat Des Lieux intervenes as part of its Breyne Law support for this audit. For reception, see provisional reception expert. Request a free quote within 24 hours. Also consult new construction heating, EPC new-construction price and new construction finishes.