The principle: the consent follows the category of works
The question always comes in the same form: what do I have to file for this project. The answer depends neither on the value of the works nor on their duration, but on the category the project falls into.
Article 3 of Presidential Decree 380 of 2001 defines the categories of building work, from routine maintenance through to urban restructuring. The code attaches a consent regime to each category, and the correct sequence of reasoning therefore has two steps: first classify the works, then identify the consent.
Reversing the two steps is the origin of most challenges. Works filed under an insufficient consent do not become lawful because the one stop building office accepted the filing: the classification remains open to challenge, and the consequences for the regularity of the property surface years later, typically on a sale.
The five questions making up the classification exercise, the framework of regimes and the consequences of the wrong consent are covered in Which building consent your project requires. It also carries the order in which to ask them.
The four regimes and their scope
The system rests on four regimes, and their boundaries are set by precise technical parameters. None of the boundaries depends on the value of the works.
| Regime | Nature | Boundary |
|---|---|---|
| Edilizia libera | No consent | Works listed in article 6 |
| CILA | Certified notification | No impact on structural elements, no alteration of elevations |
| SCIA | Certified notice | Structural or elevation impact permitted, overall volume unchanged |
| Permesso di costruire | Express instrument | New build, urban restructuring, heavy building restructuring |
Two parameters govern the whole scale. Impact on structural elements and on the elevations marks the boundary between notification and notice. Alteration of the overall volume marks the boundary between notice and express instrument.
On protected stock the scale compresses. Works altering the envelope, the overall volume or the elevations of properties protected under the code of cultural heritage and landscape require a permesso di costruire, which means that altering the elevations alone, which on ordinary stock would remain within the notice, rises to the express instrument.
The scope of the permesso di costruire, with the four conditions of heavy restructuring, standing to apply and the documents required, is examined in The permesso di costruire: when it is required. It also carries the cases where a certified notice may be used instead.
The residual character of the notification
One structural feature deserves isolating because it shapes the working method. The CILA is defined not by a list but by exclusion: article 6-bis subjects to certified notification works that cannot be brought within articles 6, 10 and 22.
It follows that there is no list of works subject to notification, but a three step identification procedure. Check whether the work falls within permit free activity; check whether it falls among works subject to a permit or to a notice; whatever falls within none of those is subject to notification.
That sequence explains why the notification cannot be the starting point of the reasoning, and it is why the most widespread error in this field consists in starting from it because the work looks modest. The real scope, the role of the certification and the risk of misuse are covered in The CILA: works covered.
Permit free does not mean unregulated
The regime of article 6 is frequently invoked wrongly, because free is read as meaning unregulated, whereas it means only not subject to a consent. The word free concerns the consent and not the checks.
Permit free works remain subject to municipal planning instruments and to sector legislation, in particular seismic, safety, fire, health and hygiene, energy efficiency, hydrogeological risk and the code of cultural heritage and landscape. Constraints continue to apply in full.
Decree Law 69 of 2024, converted by Law 105 of 2024 and known as the Salva Casa decree, widened the scope of article 6, extending among other things retractable and fully transparent panoramic glazing to the enclosure of porticoes and adding sun protection structures of the awning type. The glossary approved by ministerial decree of 2 March 2018 lists the principal works that may be carried out without consent, but it is expressly non exhaustive and inclusion in it is not enough: the work remains permit free only if it meets the substantive requirements.
Procedures and timescales
The consents differ in legal nature, and on that difference depend the moment work may start and the consequences of a defect. The allocation of liability depends on it too.
The permesso di costruire is an express administrative instrument: the municipality adopts it following a review and without it the work cannot begin. The SCIA and the CILA are privately formed consents: there is no municipal instrument but an act of the private party supported by a professional's certification, and the authority's control follows downstream.
The permit procedure is set out in article 20 on defined time limits: ten days for notification of the officer responsible, sixty days for the review and the proposed decision, thirty days for the final decision. The total gives ninety days, which is the period for concluding the procedure.
One rule deserves knowing because it has immediate operational value. The review period may be interrupted only once by the officer responsible, within thirty days of filing, and exclusively for a reasoned request for supplementary documents. The interruption is therefore unique, time bound and limited in its subject matter.
Where the authority fails to act, tacit consent operates, with one significant exclusion: it does not operate where environmental, landscape or cultural constraints apply. Where the property is subject to a constraint whose protection does not fall to the municipality, assent is obtained through a conference of services and an unfavourable outcome produces a tacit refusal.
One intermediate mechanism completes the picture. The SCIA in lieu of a permesso di costruire, provided by article 23 for exhaustively listed situations, is a consent with deferred effect: it must be filed at least thirty days before work starts and within that period the municipality may adopt a reasoned prohibition. It is onerous like the permit, which contradicts what its name suggests.
Procedures, the regime governing variations and the quality of the filing as the factor governing effective timescales are covered in The procedures for building consents. It also carries the mechanism interrupting the statutory periods.
The authorisations that layer on top
A second level of checking operates independently of the building consent, and omitting it is among the most frequent causes of procedures stalling in review. Omitting it is one of the commonest causes of a project stalling.
Permit free work on a property in a landscape protected area may require landscape authorisation. Work on a heritage asset requires authorisation from the heritage authority. Work affecting structural elements triggers the seismic requirements set by regional legislation, which in some areas take the form of prior authorisation rather than a filing.
These authorisations neither replace the building consent nor are replaced by it: they add to it. The correct checking sequence therefore comprises three distinct questions, on the category of works, on the constraints affecting the property and on the sector regimes triggered by the operations envisaged.
| Regime | Triggered by | Effect on the building consent |
|---|---|---|
| Landscape authorisation | Landscape constraint on the area | Adds to it, with its own procedure and time limits |
| Heritage authority authorisation | Protection of the heritage asset | Adds to it, with an opinion that may be binding |
| Seismic requirements | Impact on structural elements | Add to it, on a regime set by the region |
| Other sector assents | Location and nature of the works | Add to it as the case requires |
Two practical consequences follow. The first concerns timescales: sub procedures are not absorbed within the time limits of the building procedure, and realistic programming of work on a protected property starts from the longest sub procedure. The second concerns sequence: accessory applications should be started in parallel and not after the building consent is issued, because waiting adds the periods together instead of overlapping them.
It should be added that renewable energy installations now follow their own rules, identifying specific authorisation regimes to be checked separately. Referring to the ordinary regimes is therefore not sufficient.
Lawful status: where you start from
Before identifying which consent a project requires, the starting point has to be established. It is the step practice skips most often and the one producing the costliest surprises.
Article 9-bis of the code defines the stato legittimo, the lawful planning status of a property, and identifies the evidence establishing it. The scheme is documentary rather than descriptive: lawful status is established not by a survey but by consents, meaning the consent that provided for the construction or subsequently legitimised it, together with the later consents authorising works on the property.
The 2024 decree intervened in that scheme, articulating the means of proof with the stated objective of facilitating the circulation of property by preventing an untraceable remote consent from blocking transactions on buildings that are substantively regular. The actual reach of that development is being clarified by case law and by ministerial guidance.
One misunderstanding should be dispelled at once, because it is the most frequent and the most costly. A land registry plan is not a building consent, and its correspondence with the existing condition does not establish the planning lawfulness of the property. The two checks are distinct, answer to different rules and must both be carried out. The typical case is a property whose land registry plan was updated after an internal alteration carried out without a consent: land registry consistency is perfect and planning lawfulness is entirely absent.
Reconstructing lawful status is now a professional service in its own right, with its own methodology of research in municipal, land registry and other administrative archives. It should be quoted as such and started before the survey, because it is the consents found that indicate which elements the survey must check with particular care.
The check, its premises and the consequences of omitting it are covered in Lawful planning status and compliance of a property. It also carries the documents to be obtained.
The departures that are not non conformities
Not everything departing from the approved design is a breach, and this is the section deciding whether a survey closes with a certification or opens a procedure. This section decides whether a finding becomes a problem.
Article 34-bis governs construction tolerances. Paragraph 1 provides that failure to observe the height, separation distances, volume, footprint and any other parameter of individual units does not constitute a building violation where contained within 2 per cent of the measurements provided in the consent.
The 2024 decree introduced a graduated regime for departures relating to works carried out by 24 May 2024, with thresholds inversely proportional to the net floor area of the unit: 2 per cent above five hundred square metres, 3 per cent between three hundred and five hundred, 4 per cent between one hundred and three hundred, 5 per cent below one hundred, 6 per cent below sixty. The bands depend on the floor area of the unit.
Two rules accompany that regime and should be known alongside it. The date of 24 May 2024 determines which of the two regimes applies, which makes dating the departures a substantive element of the technical report. And the relevant net floor area is determined by reference to the original consent, disregarding any subsequent subdivision, with an expressly anti avoidance purpose.
The decree also introduced article 34-ter, identifying particular cases of partial non conformity removed from the ordinary sanctions regime, and articulated the rules on execution tolerances, which are tied not to percentages but to the minimal and immaterial nature of the departure. The cases identified follow a regime of their own.
One limit case law has drawn deserves attention: tolerances do not apply to extensions carried out on a property already the subject of an amnesty, because the situation presupposes failure to observe design measurements set by a previously issued consent. Tolerances do not combine with an amnesty.
Change of use
Change of use is the project in which classification matters more than the works, and it warrants separate treatment because it intersects every preceding section. The functional category decides the regime that applies.
Article 23-ter defines as significant in planning terms a change assigning the property to a different functional category among those the article lists: residential, tourist and hospitality, productive and office, retail, rural. The test is functional rather than material: an office turned into a dwelling produces a significant change even where no work is carried out.
The 2024 decree clarified that a change is treated as being without works not only where no work is carried out, but also where the works needed fall within permit free activity. And it introduced a simplifying principle with a minimum consent: a certified notice is always required for a change between functional categories of individual units, even without works, and applies in any event where the works would fall within certified notification.
The limit of the whole regime should be held firmly: the change must comply with the municipal planning rules, and case law has clarified that article 23-ter does not automatically prevail over planning agreements in force. Planning compatibility always precedes the choice of consent.
Economically the effect is direct. Moving to a functional category with a higher incidence triggers payment of the difference in development contribution, and it is the item conversion projects discover latest.
The functional categories, the consent required, the relationship with planning and the effect on the contribution are examined in Change of use. It also carries the territorial scope of the simplifications.
Regularisation: which instrument for which non conformity
There is no such thing as the Italian building amnesty, but a plurality of regimes, and the choice is not discretionary. Classification of the non conformity always precedes the choice of instrument, and it must be carried out against the consent the work would have required rather than the one that was filed.
The available regimes fall along a scale of gravity. Classifying the non conformity precedes choosing the regime.
| Situation | Instrument | Effect |
|---|---|---|
| Departure within the statutory limits | Professional's certification | No regularisation needed |
| Notifiable work carried out without notification | Late notification | Regularisation of the formality, with a penalty |
| Partial non conformity and material variations | Compliance assessment, article 36-bis | Retrospective consent, with attenuated compliance |
| More serious breaches, including absence of consent | Compliance assessment, article 36 | Retrospective consent, with full dual compliance |
| Non conformity not removable without prejudice to the lawful part | Fiscalizzazione | Penalty in lieu of demolition, no consent |
Two elements of that scale carry particular weight. They concern double compliance and the monetary penalty.
The first is the distinction between article 36 and article 36-bis. Article 36 requires full dual compliance, with the rules in force both when the work was carried out and when the application is filed, and the changing of planning instruments over time is the real practical obstacle. Article 36-bis, introduced in 2024 and widened on conversion to include material variations, provides an attenuated test. The two regimes also differ on silence: refusal under article 36, consent on expiry of the periods under article 36-bis.
The second is the nature of fiscalizzazione. Payment of the penalty extinguishes the claim to demolition but produces no building consent: the works are not demolished and do not become lawful. Presenting it to the client as retrospective consent is the gravest error in this field, because it creates an expectation of compliance with effects on the property's marketability and on future projects.
The regimes, their conditions and the recommended order of work are covered in Retrospective consent and building breaches. It also carries the expectations the rules do not meet.
The development contribution and the project budget
The development contribution is the item that turns an administrative requirement into a cost, and the one most often absent from preliminary budgets. It is also the hardest to estimate remotely.
Article 16 provides that issue of the permit entails payment of a contribution measured against the incidence of infrastructure charges and against the construction cost. The two components follow different logics: the charges compensate for the project's impact on infrastructure and services, the construction cost component is measured against the value of the works.
Neither is determined nationally. The incidence of primary and secondary infrastructure charges is set by resolution of the municipal council based on the parametric tables the region defines by class of municipality; the construction cost is determined periodically by the regions, with municipal rates. It follows that no figure read elsewhere is usable for the municipality where you are working.
The timing differs between the two components, and the difference belongs to the result of the calculation rather than to its presentation. Infrastructure charges are paid on issue of the permit, with the possibility of instalments on request. The construction cost portion, determined on issue, is paid during construction and no later than sixty days from completion of the building.
One mechanism deserves attention because it belongs to construction economics rather than procedure. By way of total or partial offset against the amount due, the holder of the permit may undertake to carry out the infrastructure works directly, with the works passing into the municipality's inalienable public assets. Whether it is worthwhile is assessed by comparing the offsettable amount with the actual cost of delivery, including the security the municipality requires and the financing cost of funding it up front.
On reductions, article 17 lists the reduction and exemption situations, and case law treats them as derogations from the principle of onerousness and therefore subject to strict interpretation. An exemption is not argued by analogy nor inferred from the purpose of the project: it is established by bringing the project within one of the situations expressly listed.
The contribution does not belong to the cost of the works and does not appear in the bill of quantities. It belongs to the other elements of the project, alongside professional fees, connections and taxes, and in public works its formal home is the quadro economico, in the section covering the sums at the contracting authority's disposal.
The two components, the timing of payment and the connection with the budget are covered in The development contribution, and the charges component with the offsetting mechanism in Infrastructure charges. It also carries the cases of reduction and exemption.
The regional and municipal dimension
None of the guidance in this page can be applied without a further step, and it is worth stating precisely because it is the difference between information and a decision. Checking the regional and municipal framework remains mandatory.
The code is national, but the subject falls under shared competence. Regions may identify by statute further works subject to a permesso di costruire; the determination of material variations is left to regional legislation; the construction cost is determined by the regions; the parametric tables for the charges are regional. And the 2024 decree has been received by the regions non uniformly, some through rules of their own.
At municipal level there are also the building regulation and the technical implementation rules, which may refine definitions and impose further requirements, and the resolutions on rates, percentages and reliefs. One element in particular should be flagged: the definitions of net floor area, gross floor area, volume and height may be refined by the building regulation in ways differing from common practice, and both the application of tolerances and the calculation of the contribution depend on them.
Checking those two levels is not an incidental control. It is part of the classification and of the estimate, and omitting it produces applications that are formally correct and substantively wrong.
The standard route on an existing property
The preceding sections compose into a sequence, and following it in order is the most economical way to set up an appointment on existing stock. Following it in order is the most economical way to work.
The first step is the documentary search. The municipal and land registry archives are interrogated, together with those of the heritage authority and of the competent regional seismic body where relevant, and the chain of consents is reconstructed. It should be started before the survey, because it is the consents found that indicate what the survey must verify.
The second step is the survey of the existing condition, complete and measured, without filtering out apparent non conformities. The survey precedes any documentary assessment.
The third step is the comparison between the two, conducted element by element rather than as an overall judgement, dating the departures so far as possible. Each non conformity must be classified individually.
The fourth step is classifying each departure: difference falling within tolerances, non conformity regularisable by late notification, non conformity requiring a compliance assessment, non conformity that cannot be regularised. It is the step at which the route and its cost are decided.
The fifth step is checking the planning compatibility of the project intended, against the instrument in force and any agreements. It necessarily precedes identifying the consent.
The sixth step is identifying the consent required, which by this point is a consequence rather than a choice. By this point it is a consequence and not a choice.
The seventh step is estimating the development contribution and placing it in the cash flow, with the two components at their respective moments. The two components follow different timings.
Two observations on that sequence. The first is that the first four steps concern the property's past and the last three its future: they are two distinct pieces of work and it is worth quoting them as such. The second is that reversing the fifth and sixth steps produces the recurring error of a formally correct application for a project the planning instrument does not permit.
The costliest errors
The recurring errors come down to a short and stable list. None of them requires special expertise to avoid.
Classifying the work by the value of the works rather than by category is the first, and leads to choosing an insufficient consent. The choice of consent is then wrong from the outset.
Starting from the certified notification because the work looks modest is the second, and skips the two steps determining whether it applies. The two classification steps are thereby skipped.
Assuming the non structural nature of the elements without investigation is the third, and is the technical mechanism behind most misuses of the notification. It is the technical mechanism producing the gravest non conformities.
Omitting the check on lawful status is the fourth, and leaves the design grafted onto an existing building of unknown regularity. The design stays grafted onto an unverified existing condition.
Confusing land registry consistency with planning lawfulness is the fifth, and blocks transactions at completion. Transactions then stall at completion.
Dating departures by approximation is the sixth, and undermines the application of the tolerance regime. The application of the tolerance regime is thereby undermined.
Classifying a non conformity against the consent filed rather than the one required is the seventh, and case law has already penalised it in the field of compliance assessment. Case law censures this error regularly.
Presenting fiscalizzazione as retrospective consent is the eighth, and creates an expectation of compliance the mechanism does not produce. It creates an expectation of compliance the procedure does not deliver.
Estimating the development contribution from figures read elsewhere is the ninth, and produces budgets the municipal determination contradicts. The municipal determination then contradicts the budget.
Checking the consent before checking planning compatibility is the tenth, and produces impeccable applications for projects that are not permitted. It produces impeccable applications for projects that are not permitted.
Note: the legislative references in this page relate to Italy and are current as at the date of publication. The subject falls under shared competence, Decree Law 69 of 2024 has been received non uniformly by the regions and case law is still developing: the text in force, the regional legislation, the planning instrument and the municipal building regulation should be checked before any operational use.