The fees of an architect for renovation cannot be compared to those for new construction. The calculation base, the complexity of preliminary diagnostics, and the uncertainties related to the existing structure systematically place the cost of an architect for renovating a house or an apartment above the usual references cited for new builds.
Percentage difference between renovation and new construction: what the scales reveal
A complete architect’s mission for new construction generally ranges between 8 and 12% of the total cost of the work. In renovation, the indicative scales rise to 12 to 18% of the total cost of the work. This difference is not arbitrary: it reflects the additional design required due to an existing structure, whose framework, networks, and materials are never entirely predictable.
We observe that most consumer articles cite a single range without distinguishing between new and renovation. This confusion skews the comparison from the very first quote. A project holder budgeting 10% fees for a major renovation underestimates the reality in several respects.
The details of the cost of an architect for renovation also depend on the chosen compensation method, and the percentage is just one of the three common contractual formulas.
Payment methods for architects in renovation: percentage, fixed fee, hourly rate
Three billing methods coexist, and the choice of the right method depends on the exact nature of the assigned mission.
Percentage of the total cost of the work
This is the most common formula for a complete mission (design, permit application, consultation with companies, site supervision). The percentage applies to the net amount of the work actually undertaken. In renovation, this percentage is higher than in new construction because the time spent on surveys, structural analysis, and coordination with diagnosticians increases each phase.
A point often overlooked: the rise in the average cost of renovations per m² since 2024-2025 mechanically increases the nominal amount of fees, even when the rate remains stable. Avoltis Rénovation indicates an average renovation cost in France of 900 to 1,600 euros per m² in 2025, a slight increase compared to 2024. Specifically, with the same rate of 14%, the fee envelope increases because the base amount increases.
Fixed fee
The fixed fee is suitable for well-defined missions: feasibility study, preparation of plans, building permit application. The price is set before signing. This formula provides budget reassurance, but it requires precisely framing the scope. Any amendments during the mission generate additional costs.
Hourly rate
Reserved for occasional interventions (consultation, site visit, technical arbitration), the hourly rate is not suitable for a complete renovation mission. It remains useful for a consultation prior to the project, before committing to a global contract.
Factors that affect the fees of an architect in renovation
Not all renovation projects generate the same level of fees. Several technical parameters influence the final quote.
- The structural complexity of the existing building: a load-bearing wall to be restored, a degraded framework, or outdated networks increase the design time and the number of plans to be produced.
- Geographical location and urban planning constraints: a project located in an ABF zone (Architects of the Buildings of France) or in a heritage area imposes additional procedures, back-and-forth with the administration, and sometimes constrained material choices.
- The extent of the mission: an architect commissioned only for the plans charges significantly less than an architect responsible for the complete mission until the project is completed.
- The total amount of the work: the higher the construction budget, the more the applied percentage tends to decrease in relative value, but the amount in euros remains higher.
The experience of the professional also plays a role. A recognized firm specializing in the renovation of old buildings justifiably charges more than a generalist architect who has recently set up.
Reading an architect’s fee quote: items to check
A well-drafted fee quote details each phase of the mission. We recommend systematically checking the breakdown between the following items: sketch and preliminary project, building permit file, consultation with companies, project execution management, assistance at project completion.
Each item must mention its calculation method (percentage, fixed fee, or hourly rate) and the associated deliverable. A quote that states a total amount without breakdown by phase does not allow for comparison. If the architect charges by percentage, the quote must specify the base amount used (estimated net amount of the work) and the revision clause in case of budget changes during the project.
Be wary of mentions regarding additional costs: travel, plan printing, topographical surveys. These items can represent a significant additional cost if they are not included in the fixed fee or the announced percentage.
DPLG architect and interior architect: two professions, two pricing structures
The confusion between DPLG architect (or DE-HMONP) and interior architect persists. However, only the architect registered with the Order can submit a building permit and intervene on the structure of the building. The interior architect focuses on layout, finishing materials, and decoration without touching the structural work.
The pricing structures differ. The interior architect often charges per m² or a fixed fee, with amounts lower than those for a complete DPLG architect mission. For a renovation project that includes structural modifications, hiring a DPLG architect remains the only option compliant with regulations, especially when the floor area exceeds the legal threshold.
For a project limited to redistributing spaces without touching the structure, an interior architect may suffice and significantly reduce the fee budget.
The cost of an architect for renovating a house or an apartment is always viewed in relation to the actual complexity of the structure and the scope of the mission. A quoted percentage without context says nothing. What determines the final budget is the precision of the quote, the distinction between new and renovation, and the level of service expected, from the sketch to the completion of the project.