Amending building permit during construction: how far to amend without refiling

A technical problem with the foundations, a tenant who demands a mezzanine, a safety commission that requires a second exit, a financial plan that no longer works without two additional dwellings: few operations are delivered strictly in line with the initial permit. The question facing the project owner (maître d'ouvrage) is then always the same, and it is binary: is an amending building permit enough, or must a new building permit be filed during construction? The stakes are not formal. The amending permit is incorporated into the initial permit and opens to third parties only an appeal limited to its own provisions; refiling places the whole project under the planning rules in force on the date of the new application and reopens a full appeal period. This guide sets the boundary between the two, measures the effects on the operation timetable and on litigation exposure, and proposes a method for choosing a course so as to secure the usability of the asset through to resale.

Three levels of formality, not two

Before setting the amending permit against the new permit, one must set aside what requires no formality at all. A purely internal change, without creation of floor area or ground coverage, without change of use or sub-category of use, and without alteration of the exterior appearance, requires no additional authorisation. Moving a partition on an office floor, reworking a recessed technical network, or adapting a suspended ceiling are matters for the building site, not for planning law.

At the second level is the amending building permit. It is not defined by a single text: the French Urban Planning Code mentions it, notably in Article L. 600-5-2, but its conditions have been developed by the administrative case law. It is analysed as a decision that is incorporated into the initial permit, which continues to exist. The applicant remains the holder of a single authorisation, made up of the original permit as amended.

At the third level, the new building permit. It amends nothing: it authorises a distinct project. Legally, it may coexist with the initial permit or replace it, but it is examined, displayed and open to challenge as a stand-alone authorisation. It is this difference in nature that governs most of the economic consequences examined below.

The conditions of admissibility of an amending permit during construction

Four conditions must be met for a building permit amendment during construction to take the amending permit route.

• The initial permit must exist and not have been annulled. One does not amend an authorisation that has disappeared from the legal order.
• The initial permit must not have lapsed. Article R. 424-17 of the French Urban Planning Code sets validity at three years, the permit becoming void if the works are not begun within that period or if they are interrupted for more than a year.
• The works must not be completed. Once completion has occurred, and a fortiori once the declaration certifying completion and conformity of the works (DAACT) has been filed under Article R. 462-1, the amending permit route is closed: additional works fall under a new authorisation.
• The planned changes must not upset the general design of the project.

It is this last condition that concentrates the litigation. The old formulation, which prevented the amending permit from relating to substantial elements, has given way to a more flexible approach: the administrative courts now accept that an amending permit may relate to the siting, dimensions or appearance of the building, provided that the initial project is not upset in its overall design. The criterion is therefore not the intrinsic importance of the change, but its effect on the general economics of the operation.

Indications of upset

No regulatory grid exists. The analysis is case-by-case and is built from a body of indications. The following are regularly treated as revealing an upset: a change of use of the whole building, for example from an office scheme to a residential scheme; an increase in floor area out of all proportion to the authorised project; a change in the number of buildings or in their siting on the plot to the point of redefining the site plan; the complete restructuring of the scheme, such as the conversion of a hotel into a managed residence divided into lots.

Conversely, the following remain within the scope of the amending permit: a measured addition of area, the repositioning of a lift shaft, changes to façade openings, the replacement of a cladding material, the adaptation of the roof to receive photovoltaic panels, the creation of a mezzanine at a tenant's request, or the bringing of an access into compliance as required by the safety commission.

The useful method is to reason by comparison: if the initial plan and the amended plan were shown to a third party, would that person recognise the same project? If the answer is no, refiling is required.

Why refiling costs more than the examination it triggers

The choice is rarely decided on the examination period. It is decided on the loss of crystallised rights.

A building permit crystallises the planning rules applicable on the date of the decision. A permit issued under a local urban plan that predates a revision continues to produce its effects, and the amending permit, which is incorporated into it, is assessed only for what it amends. A new building permit for a works in progress, by contrast, is examined against the law in force on the date of the new application. The operation is then exposed to all the changes that have occurred since: a new PLU or a bioclimatic PLU, tighter rules on height, deep-soil area or parking, new easements, an extended heritage protection perimeter, amended development and programming guidelines, and requirements of functional or social mix.

Cascading consequences are added to this. Crossing a threshold may trigger an environmental assessment or a case-by-case review. A change in taxable area leads to an additional assessment of development tax and, where applicable, of the preventive archaeology fee. In an off-plan sale (vente en l'état futur d'achèvement), a significant change to the scheme affects the descriptive notice and the undertakings given to reservation holders under Articles L. 261-11 et seq. of the French Construction and Housing Code, with a risk that reservations are called into question and an immediate effect on the completion guarantee. On the construction contract side, the amending permit results in a variation and a service order; refiling, for its part, often suspends the works and brings the operation into negotiation over the contractor's standing time.

A last point, frequently underestimated: filing an amending permit does not in itself extend the validity of the initial permit. When the operation nears the end of the three years, the application for extension provided for in Articles R. 424-21 and R. 424-22 of the French Urban Planning Code, to be made at least two months before the end of the validity period, must be pursued in parallel and not in place of the amending permit. The commencement of works and the extension mechanism are detailed in our article on extending a building permit.

Effects on the operation timetable

The amending permit is examined as a stand-alone application, within the ordinary-law periods of Article R. 423-23 of the French Urban Planning Code: two months for a detached house, three months for other building permits. These periods are extended in the event of compulsory consultation, notably in the vicinity of a listed historic monument or in a remarkable heritage site (site patrimonial remarquable), where the opinion of the architecte des Bâtiments de France (the State architect responsible for heritage protection) conditions the decision. The administration's silence at the end of the period amounts in principle to a tacit decision, subject to the cases in which the Code excludes this rule.

In addition to the examination, there are three sequences that the operation schedule must treat as milestones, not as contingencies.

• Display on the site, governed by Article R. 424-15 and the implementing orders, which conditions the triggering of the third-party appeal period. Display that is irregular or not recorded by a bailiff leaves the period running indefinitely.
• The two-month third-party appeal period provided for in Article R. 600-2, which runs from the first day of a continuous two-month period of display on the site.
• The administrative withdrawal period of Article L. 424-5: the permit, even a tacit one, may be withdrawn only if it is unlawful, and within three months of the decision. After that date, the authorisation is stabilised as against the administration.

A well-sequenced filing of an amending permit often allows the works not concerned to continue during the examination. Refiling, by contrast, in practice requires the affected works to stop, since their execution no longer rests on any title. Between the two scenarios, the difference in timetable is rarely counted in weeks: it is counted in quarters, and it translates into financial carrying costs.

Article L. 424-5 of the French Urban Planning Code: A building, development or demolition permit, whether tacit or express, may be withdrawn only if it is unlawful and within three months of the date of that decision.

Third-party appeal period: what the amending permit reopens, and what it does not

This is the decisive advantage of the amending permit route, and the reason why its characterisation is so disputed.

The amending permit is a decision adversely affecting third parties: it is displayed and it is open to an appeal for abuse of power under the ordinary conditions. But the appeal open against it does not allow the challenge to the initial permit, which has become final, to be reopened. Third parties can usefully invoke only the defects specific to the amending permit, that is, the illegalities affecting the elements that it amends. The foundation of the project, cleared by the expiry of the period under Article R. 600-2, remains out of reach.

A new permit produces the opposite effect. Covering the whole project, it fully reopens the litigation debate: siting, height, use, parking, landscape integration, everything becomes open to challenge again. For an asset being marketed or refinanced, this reopening is the heaviest risk exposure of the operation, since it occurs at the moment when cash is already committed.

Several procedural safeguards mitigate this exposure without removing it. Article L. 600-1-2 restricts the third party's standing to direct harm to the conditions of occupation, use or enjoyment of their property. Article L. 600-1-1 makes the admissibility of associations conditional on the filing of their articles before the display at the town hall of the application. Article R. 600-1 requires, on pain of inadmissibility, notification of the appeal to the author of the decision and to the holder of the authorisation within fifteen clear days. Article R. 600-5 crystallises the grounds two months after communication of the first statement of defence. Article R. 600-6 gives the judge ten months to rule on appeals against a permit to build a building comprising more than two dwellings. Finally, for certain housing authorisations located in high-demand areas, the right of appeal is removed by Article R. 811-1-1 of the French Code of Administrative Justice, the administrative court ruling at first and last instance, a scheme that has been extended several times. On third-party standing and the starting point of their appeal period, see our analysis of third-party appeals against a building permit.

A last lock, often decisive in practice: Article R. 600-3 of the French Urban Planning Code bars any action for annulment of a building permit once six months have elapsed from completion of the building, the date of the DAACT giving rise to a presumption of that completion. Bringing the works to completion and filing the DAACT without delay is therefore, in itself, an act of legal security.

The amending permit as an instrument of regularisation in litigation

The amending permit is not only a site management tool. It is the preferred vehicle for regularising a permit under challenge, in conjunction with Articles L. 600-5 and L. 600-5-1 of the French Urban Planning Code.

Where a defect affects only part of the project, the judge may order a partial annulment under Article L. 600-5 and set a period for regularisation. Under Article L. 600-5-1, the judge may stay the proceedings after finding that a defect making the permit unlawful is capable of being regularised, and allow the beneficiary a period to produce a regularisation measure. That measure most often takes the form of an amending permit.

Two points deserve the project owner's attention. First, regularisation may take place spontaneously, without waiting for the judge's invitation: filing an amending permit during the proceedings makes it possible to neutralise a ground before the hearing, provided it is anticipated before the grounds are crystallised. Second, Article L. 600-5-2 reserves to the judge already seised of the initial permit the challenge to the amending permit issued with a view to regularising, which avoids the multiplication of parallel proceedings and wearing-down strategies. The choice of regularisation act and the timetable for the decisions are dealt with separately in our article on regularising a permit under challenge during proceedings.

Regularisation by an amending permit nevertheless presupposes that the defect can be regularised without upsetting the project. A defect arising from breach of a height rule can often be corrected; a defect arising from the land being unbuildable or from the incompatibility of the use with the zoning cannot. The analysis of whether regularisation is possible must be carried out as soon as the appeal is received, and not on reading the submissions of the public rapporteur (rapporteur public).

Building without an amending permit: what is inherited on resale

Carrying out works that do not conform to the permit without seeking an amending permit exposes the owner to a chain of consequences whose cost often appears several years later, at the time of sale.

At the completion stage, the competent authority has, under Article L. 462-2 of the French Urban Planning Code, three months to challenge the conformity of the works, extended to five months in the cases of compulsory inspection referred to in Article R. 462-7. A challenge to conformity deprives the project owner of the certificate of non-objection to conformity, a document that every institutional purchaser and every lender requires in audit. Without that document, the sale is negotiated with an escrow, at a discount or under a specific warranty, when it is not blocked altogether.

To this are added the administrative enforcement tools: the order to stop works under Article L. 480-2, and the formal notice backed by a daily penalty under Articles L. 481-1 to L. 481-3, the amount of which may reach €500 per day of delay, up to a total of €25,000. On the criminal side, Article L. 480-4 of the French Urban Planning Code penalises carrying out works that do not conform to the authorisation with a fine of between €1,200 and an amount that, in the case of construction of floor area, may reach €6,000 per square metre, and €300,000 in other cases, imprisonment being incurred in the event of a repeat offence. Individual managers are concerned in the same way as the company.

Finally, third parties' civil action is not extinguished by the administration's silence. Demolition under Article L. 480-13 admittedly presupposes the prior annulment of the permit and the location of the building in one of the zones exhaustively listed, but the claim for damages remains largely open. For an investor, the issue is therefore not the probability of demolition: it is the provision to be set aside and the reservation that the purchaser's auditor will enter in the report.

A method for the project owner to choose a course

The decision is built in five stages, in this order.

• Characterise the change against the authorised project: area, ground coverage, siting, height, use, exterior appearance. Any change significantly affecting at least two of these parameters calls for an analysis of upset.
• Check the validity of the initial permit and the progress of the works. A permit close to lapsing or works that are almost complete mechanically narrow the window for an amending permit.
• Simulate the project under current law. This is the decisive step: if the project, refiled today, would no longer be authorisable or would be authorisable only on worse terms, the amending permit should be preferred whenever it is defensible, and the scope of the change narrowed accordingly.
• Measure the residual litigation exposure. Existence of identified third parties, history of local opposition, presence of an established association, prior administrative appeal to the issuing authority (recours gracieux).
• Secure the evidence: compliant display recorded by a commissaire de justice (bailiff), retention of receipts, and a DAACT filed without delay on completion so as to start the bar on appeals under Article R. 600-3 running.

Where the analysis places the project on the borderline, an intermediate solution exists: splitting the change. Adaptations clearly compatible with the general design are made the subject of an immediate amending permit; the major change to the scheme is deferred and dealt with, after completion and clearing of the time limits, by a separate authorisation covering only the additional works. This sequence lengthens the timetable, but it preserves the rights acquired on the foundation of the operation.

Conclusion

The choice between an amending permit and a new permit is not a question of procedure, it is an investment decision. The amending permit preserves the crystallisation of the rules and confines third-party appeals to the amended elements alone; refiling puts the operation back in contact with the law in force and reopens the whole of the litigation debate, at the worst point of the cash cycle. The firm's position is clear: as long as the general design of the project is not upset, the amending permit route should be preferred, and the scope of the application calibrated so that it remains so.

Before any building permit amendment during construction, have a written characterisation note prepared comparing the authorised project and the amended project parameter by parameter, together with a simulation of the project under the law applicable today. This note has three immediate uses: it sets the strategy, it documents the project owner's good faith in the event of a conformity inspection, and it answers in advance the audit that the purchaser will carry out on the day of sale.

Frequently asked questions

Up to what stage of the works can an amending building permit be filed? As long as the works are not completed and the initial permit has not lapsed. Completion definitively closes this route: once the declaration certifying completion and conformity of the works has been filed under Article R. 462-1 of the French Urban Planning Code, additional works fall under a new authorisation. In practice, an amending permit filed when the work concerned has already been carried out raises a double difficulty: the regularity of the filing and the characterisation of works executed without a title within the meaning of Article L. 480-4.

Does an increase in floor area systematically require a new building permit? No. No regulatory threshold governs the switch to a new permit. The criterion is the upsetting of the general design of the project, assessed from a body of indications. A measured extension, consistent with the site plan and the authorised use, falls within the amending permit; an increase that redefines the scheme, the massing or the number of buildings requires refiling.

Does the amending permit reopen the appeal period against the initial permit? No. The amending permit is incorporated into the initial permit, but third parties can usefully challenge only its own provisions. The initial permit, which has become final through the expiry of the two-month period provided for in Article R. 600-2 of the French Urban Planning Code, does not become open to challenge again. The amending permit must, however, be the subject of its own regular and continuous display in order to trigger the appeal period applicable to it.

What is the examination period for an amending building permit? The ordinary-law periods of Article R. 423-23 of the French Urban Planning Code apply: two months for a detached house and its outbuildings, three months for other building permits. These periods are extended in the event of compulsory consultation, notably where the project is located in the vicinity of a listed historic monument or in a remarkable heritage site and requires the opinion of the architecte des Bâtiments de France. To this period are added the two months for third-party appeals and the three months for administrative withdrawal under Article L. 424-5.

Does filing an amending permit extend the validity of the initial permit? No, it does not in itself amount to an extension. The permit remains subject to the three-year validity period of Article R. 424-17 and to lapse if the works are interrupted for more than a year. When the deadline approaches, the application for extension provided for in Articles R. 424-21 and R. 424-22, to be submitted at least two months before expiry, must be pursued in parallel with the amending permit.

Can an amending permit regularise a permit under challenge before the administrative court? Yes, and it is its most strategic use. Under Article L. 600-5-1 of the French Urban Planning Code, the judge may stay the proceedings and allow a period for producing a regularisation measure, which generally takes the form of an amending permit. The beneficiary may also regularise spontaneously, before the crystallisation of grounds under Article R. 600-5. Article L. 600-5-2 then reserves the challenge to that amending permit to the judge already seised, which avoids the opening of a second set of proceedings.

What does a project owner risk who carries out non-conforming works without filing an amending permit? A challenge to conformity by the administration within three months of the DAACT, extended to five months in the case of compulsory inspection, and therefore the impossibility of obtaining the certificate of non-objection to conformity required in a sale audit. To this are added the order to stop works under Article L. 480-2, the administrative daily penalty under Articles L. 481-1 to L. 481-3 capped at €25,000, and the criminal penalties of Article L. 480-4. The most lasting economic effect remains the discount and the reservations entered in the purchaser's audit report.