Strengthening Historical Heritage in 2026: How 'Reversible Technologies' Leverage Flemish Grant Requirements

By the editorial team Monumentvault · 16 September 2026

The renovation of historical heritage is caught in a complex balancing act. On the one hand, centuries-old buildings suffer from structural fatigue, foundation issues, and the need to comply with contemporary safety standards. On the other hand, these essential stabilization works clash head-on with heritage conservation laws. In many countries, government regulations are inadequate for strengthening historic buildings, simply because they are fundamentally tailored to new construction.

This discrepancy creates a vacuum for architects and engineers. Conventional methods for structural reinforcement—such as injecting concrete or anchoring heavy steel profiles into historic masonry—are often destructive and irreversible. While they do guarantee stability, they simultaneously destroy the very heritage value the law seeks to protect. In practice, this leads to denied permits and stalled grant applications. The key to breaking this deadlock lies in a different engineering approach that reconciles modern safety requirements with Flemish conservation principles through reversible mixed technologies (RMTs): fully removable structures with reversible connections that leave the historic core undamaged.

Key Takeaways

Innovative reinforcement: Developed within the EU Prohitech project and various other European programs, reversible mixed technologies (RMTs) offer a method to secure heritage buildings without permanently altering the original structure.
Financial mechanisms: According to the Flanders Heritage Agency, the coverage rates and maximum accepted cost estimates of the Flemish Heritage Grant depend on current regulations, the chosen procedure, and the type of heritage, provided one navigates the strict procedural pitfalls regarding pre-financing and VAT.
Commercial urgency: Since January 1, 2026, large non-residential building units with a usable floor area of less than 1,000 m² must hold a valid EPC NR certificate, regardless of sale, lease, or any other transfer, while investors in non-residential buildings have been excluded from the regular Mijn VerbouwPremie since March 1, 2026.

Why Standard Construction Norms Destroy Heritage

The Architectural Deadlock

Standard building codes are designed for maximum efficiency and safety using modern materials. When engineers apply these norms to a historic property, it inevitably results in heavy, invasive interventions. The Flanders Heritage Agency, however, operates from a completely different frame of reference. Flemish regulations explicitly state that elements or features registered as valuable, or which form an essential part of the original design, may only be replaced or renewed if it is absolutely necessary from a building physics perspective.

Strict Requirements for Replacement

This prerequisite of 'building physics necessity' is the first major hurdle. Even if an engineer can prove that historic wooden floor joists or a masonry arch can no longer support modern loads, outright demolition or replacement is not permitted. If replacement or renewal ultimately proves unavoidable, strict aesthetic and material restrictions apply. The original state always serves as the baseline and must be matched as closely as possible. In practice, this dictates using the same material, color, shape, layout, and profiling.

For a structural engineer, this presents a complex challenge. Strengthening a subsiding facade with a reinforced concrete structure fundamentally changes both form and material. Installing visible anchors or steel tie rods alters the visual profile. Consequently, standard structural solutions are almost always rejected by heritage inspectors, leading to stagnation in critical renovation projects and the forfeiture of potential subsidies.

The RMT Solution: How European Engineers Navigate Flemish Heritage Rules

What Are Reversible Mixed Technologies?

To resolve the conflict between structural safety and heritage preservation, the European engineering community offers a technological answer. Initiatives such as the EU Prohitech project and various other academic and European programs have applied performance-based design (PBD) to the conservation of historic and monumental buildings using reversible mixed technologies, while simultaneously developing codification that aligns with structural Eurocodes. This scientific approach empowers architects to unite safety and preservation in their structural studies.

Reversible mixed technologies (RMTs) stand out due to their fundamental design principle: they are entirely removable and integrate components of varying materials or construction methods into a single, cohesive structure. Instead of anchoring steel beams into centuries-old masonry using chemical resins, RMTs utilize reversible connections and clamping systems that support the historic structure without causing damage.

The Match with Flemish Regulations

This European innovation offers a conceptual approach to respecting the strict guidelines set by the Flanders Heritage Agency. Specifically, Flemish regulations stipulate that interventions aimed at increasing sustainability, comfort, or energetic and technical optimizations must respect the existing heritage elements and features. Furthermore, extensions are permitted when they preserve or enhance these heritage characteristics and preferably remain visually unobtrusive.

By applying the RMT philosophy, a structural reinforcement legally shifts from a 'destructive replacement' to a 'non-disruptive technical extension.' Because the technologies are fully removable (reversible) and leave original materials intact, the requirement that replacement is only allowed if 'necessary for building physics' is cleverly bypassed. There simply is no replacement. The historic condition is preserved untouched beneath or alongside the added structure, providing projects with a solid procedural foundation to qualify for heritage grants.

The Financial Equation: The Heritage Grant and the VAT Trap

The Grant Ceiling and the Base Premium

Once the structural design utilizing reversible technologies is approved, the focus shifts to financial feasibility. For protected heritage in Flanders, there are roughly two grant procedures: the simplified standard procedure and the targeted call for projects that align with a specific launched theme. For most structural renovations, the standard procedure is the most accessible route. Alongside this standard procedure, thematic calls often serve as an important alternative for extensive works, though their exact modalities evolve regularly.

Within this procedure, the Flanders Heritage Agency determines the base premium and any potential increases based on current regulations and the type of heritage. While this sounds lucrative, there is a limit to the calculation basis: only a maximum accepted cost estimate is considered for calculating the grant, and the exact ceiling depends on the prevailing regulations.

The Impact of VAT and Prefinancing

To understand the true impact on a construction budget, we must translate these parameters into a concrete financial flow. Suppose a structural heritage renovation utilizing RMTs is budgeted at 300,000 euros, excluding VAT.

Ceiling: According to the Flanders Heritage Agency, a maximum amount applies to the cost estimate. In this example, the portion of costs exceeding any applicable current ceiling falls outside the scope of the subsidy.
Grant: The prevailing premium percentage is applied to the maximum accepted amount, resulting in a capped maximum grant.
VAT Exclusion: For the calculation of this heritage grant, VAT is not eligible for funding and is excluded from the subsidy amount.
Reduced VAT Rate: According to the FPS Finance, renovation works on a home at least 10 years old, carried out and invoiced by a contractor to the end user, fall under the reduced VAT rate of 6% (provided it is used primarily for private purposes). For non-residential heritage buildings, this reduced rate does not apply automatically; the VAT regime depends on the specific nature and use of the building and must be assessed on a case-by-case basis.
Fossil Fuels: Also according to the FPS Finance, the installation of fossil fuel heating has been excluded from this favorable tax regime since July 1, 2025, and is subject to the full 21% VAT rate.
Prefinancing: Under the standard procedure, the applicant must prefinance all works themselves. The heritage grant is only paid out as a lump sum after the works are completed. Invoices must be submitted within two years following the grant award.

Finally, the standard procedure carries a strict procedural requirement that architects must closely monitor: barring specific exceptions for urgent maintenance or preventive conservation, works may only commence after the formal grant award by the government. Anyone who begins preparatory work—such as erecting scaffolding or stripping non-historical elements—before receiving approval risks losing the right to the grant, as determining whether this constitutes the formal start of works depends on the interpretation of the Flanders Heritage Agency.

The Double Squeeze in 2026: Why Commercial Heritage Must Act Quickly

New Obligations Since 2026

The financial picture is challenging enough for residential heritage, but for non-residential heritage properties—such as historic townhouses serving as offices or old farmhouses converted into hotels—the situation has become financially demanding in 2026. According to VEKA, regulations were tightened on January 1, 2026: every large non-residential building unit with a usable floor area of less than 1,000 square meters must possess a valid EPC NR (Non-Residential). This obligation now applies universally, regardless of sale, lease, or any other transfer.

This EPC NR mandate forces owners of commercial heritage into urgent energetic and structural investments. Until recently, companies could partially rely on general renovation subsidies, but that escape route has definitively closed. As of March 1, 2026, an investor in a non-residential building is no longer eligible for the regular Mijn VerbouwPremie upon application. As a result, the specialized Heritage Grant becomes an essential financial pillar for upgrading and strengthening protected commercial real estate.

Tax Pitfalls for Companies

However, when companies utilize this Heritage Grant, they run into a tough fiscal reality that impacts the project's profitability. If a company claims restoration costs as a business expense or investment for corporate tax purposes, the received heritage grant must inevitably be booked as revenue. While tax legislation does not offer an explicit and general corporate tax exemption for grants distributed by the Flanders Heritage Agency, the fiscal impact is nuanced. Tax authorities may classify this premium as a capital subsidy, allowing the taxation to be spread over time under certain conditions as the investment depreciates. The concrete fiscal handling depends on the accounting and tax treatment of the investment and should be discussed with a tax advisor.

Frequently Asked Questions (FAQ) on Structural Heritage Renovations

Can I apply for an advance on the Heritage Grant to cover the heavy startup costs of an RMT installation?

No, under the current standard procedure, the system is entirely based on retrospective payment. The client is obligated to prefinance the full amount with their own funds. The subsidy is always paid out in a single lump sum after all works have been completed and correctly invoiced. For this standard procedure, invoices must be submitted within two years of the grant award.

Does the EPC NR obligation still apply if I am not selling or renting out my historic commercial property?

Yes. According to VEKA, the requirement to hold a valid EPC NR for large non-residential building units with a usable floor area of less than 1,000 m² has applied universally since January 1, 2026, regardless of whether there is a sale, lease, or any other transfer involved.

Conclusion: The Future of Historical Construction

The integration of advanced, reversible engineering solutions marks a fundamental paradigm shift in how we handle our built past. Historic structures are no longer treated as fragile museum pieces to be conserved only in their weakness, nor as obstacles to modern commercial use. By supporting the structural framework in a dynamic and non-destructive manner, a new form of heritage architecture is emerging. The challenge for the coming decades will not lie in the dogmatic rejection of every modern technique, but in the further refinement of performance-based design frameworks that fortify our history against future climate and usage demands, without compromising the soul of the monument.