Design changes during construction in Italy: building title, builder contract and site supervision

Design changes during construction are modifications to the project decided while the site is open: a window moved, a staircase redrawn, a façade material replaced. On a private house in Italy they happen almost every time: the site reveals what the drawings did not show. The catch is that the same change touches two separate things: the building title issued by the municipality and the contract signed with the builder. Both have precise rules, and a change agreed verbally can become a planning breach or a dispute over the price.

This guide explains how design changes during construction are handled on an Italian house: variants to the building title under Presidential Decree 380/2001 (the national building code), essential variations, the builder contract under the Civil Code, site supervision, cost, time, structures and protected landscapes. It is written by Federico Cappellina Architects, an architecture practice in Verona that designs houses in north-east Italy and Lombardy and supervises their construction, for foreign owners. It is not legal advice or a binding technical opinion: each case needs a licensed professional, and regional and municipal rules vary.

Design changes during construction in brief

Design changes during construction always have two sides: the planning side, towards the municipality, and the contract side, towards the builder. Both must be handled in writing.
Variants to a building permit (permesso di costruire) that do not affect planning parameters and volumes, do not change the use or the building category, do not alter the outline of protected buildings and do not breach the permit’s conditions can be carried out with a SCIA, a certified notice of start of works (Presidential Decree 380/2001, Article 22, paragraph 2).
Variants that do not amount to an essential variation can also be carried out with a SCIA, reported at the end of works with a professional’s statement, after any consent required for protected areas has been obtained (Article 22, paragraph 2-bis).
Essential variations (variazioni essenziali) are defined by each Region within the criteria of Article 32. A change of this kind is not a minor variant and must be authorised as such before it is built.
Under the construction contract the builder may not introduce changes the owner has not authorised, and the authorisation must be proved in writing (Civil Code, Article 1659).
In our practice all design changes during construction go through a written change order signed by the owner, with drawings, price and time, before the builder carries them out.

Design changes during construction on a single-storey villa: CD Home in Verona on its lawn, a project by the studio — CD Home, Verona: a single-storey villa, a project by the studio shown as a reference of language, not as an example of design changes during construction.

What design changes during construction are

On an Italian site the word variante in corso d’opera is used for any gap between what is being built and what was designed and authorised. It covers very different situations. There is the change the municipality must know about, because it modifies the drawings attached to the building title. There is the change that concerns only the contract, such as replacing one floor finish with another at a different price. And there is the change that concerns both, which is the most common case on private houses.

The first question is therefore not «can we do it?» but «what does it change?». An interior finish may not interest the municipality but may change the price. Moving a window on a façade may be irrelevant to the price but relevant to the permit, especially on a protected building. An extension of a few square metres can affect volume, structures, distances and the bill of works at the same time. Design changes during construction are read on three tables: building title, contract, and safety and structures.

Design changes during construction and the building title: three routes

Article 22 of Presidential Decree 380/2001, in the current text we read on Normattiva (the official Italian legislation database, text in force since 17 July 2020), governs variants to a building permit that can be made with a SCIA (segnalazione certificata di inizio attività). Together with Article 32 on essential variations, it draws in practice three routes for design changes during construction. The route depends on the extent of the change, not on its urgency or its cost.

Minor variant with a SCIA (Article 22, paragraph 2)

Variants to building permits can be made with a SCIA when they meet four conditions:

they do not affect planning parameters and volumes;
they do not change the intended use or the building category;
they do not alter the outline of the building, where the building is protected under Legislative Decree 42/2004, the cultural heritage and landscape code;
they do not breach any conditions written into the building permit.

The text adds two useful points. For the purposes of planning control and of the certificate of habitability, these SCIAs form an integral part of the procedure of the main building permit. And they can be filed before the declaration that works are complete. In other words, the minor variant is not a separate title: it attaches to the original permit and follows it through to habitability.

Non-essential variant with a SCIA (Article 22, paragraph 2-bis)

Paragraph 2-bis allows variants to building permits that do not amount to an essential variation to be made with a SCIA, provided they comply with the planning and building rules. These variants are carried out only after any consent required by the rules on landscape, hydrogeological, environmental, historic, artistic and archaeological protection and by other sector rules has been obtained, and they are reported at the end of works with a statement by the professional.

The difference from paragraph 2 is practical. Paragraph 2 covers changes that stay within the parameters and volumes of the permit. Paragraph 2-bis opens a wider field, bounded by the notion of essential variation. Where design changes during construction affect a protected property, the opinion or authorisation of the heritage or landscape authority comes before the works: you do not build first and ask afterwards.

Substantial variant: a new title before building

When a change falls outside paragraphs 2 and 2-bis, because it affects volume or planning parameters or because it is an essential variation, it must be authorised with a building permit before it is built. In our practice we call it a substantial variant: for the municipality it is in every respect a new project to be reviewed, with the timescale of a permit.

Article 22, paragraph 4, also allows ordinary-statute Regions to widen or narrow by law the scope of the SCIA, so the rule for each territory must be checked in the regional law and the municipal regulation. Our guide to the building permit in Italy explains the main procedure.

Essential variations: the boundary of design changes during construction

Article 32 of Presidential Decree 380/2001 (text in force since 28 July 2024) leaves it to the Regions to establish which changes to the approved project are essential variations. An essential variation exists only where at least one of these conditions occurs, summarised below:

a change of use that implies a change in planning standards (the public-service provisions linked to each use);
a considerable increase in volume or floor area, assessed against the approved project;
substantial changes to the planning and building parameters of the approved project, or to the position of the building on its plot;
a change in the characteristics of the authorised building intervention;
a breach of the seismic building rules that is not merely procedural.

Paragraph 2 of the same article excludes from essential variations those that affect the extent of ancillary volumes, technical volumes and the internal layout of individual dwellings. Paragraph 3 states that the interventions in paragraph 1 carried out on properties under historic, artistic, architectural, archaeological, landscape, environmental or hydrogeological protection, or within national and regional parks and protected areas, are treated as works in total non-conformity with the permit.

That reference to total non-conformity matters. Article 31, paragraph 1 defines as total non-conformity works that produce a building entirely different in type, volume or use, or volumes beyond the limits of the project that form a building, or part of one, usable on its own. Unauthorised design changes during construction on a protected property can therefore fall into the most serious category. The thresholds of a «considerable increase» are not in national law: they are in regional laws, which must be read for the specific case.

Design changes during construction under a CILA or SCIA

Many renovation sites have no building permit but a CILA (a certified notice of works by a licensed professional) or a SCIA, as explained in our guide to CILA and SCIA renovation permits. Article 22, paragraphs 2 and 2-bis, speaks expressly of variants to building permits. For works started with a CILA or SCIA, in our practice the change is handled by filing a new notice that updates the drawings, before building the modified works or, where local practice allows, before the end of works.

Municipal practice differs here, and the technical office should be asked how it treats variants to titles other than a permit.

The same applies when a change alters the nature of the intervention. A renovation that started as interior works and, during construction, comes to involve façades, structures or uses may need a different title from the initial one. A change of use and splitting a property into several units are two typical cases in which the variant changes how the works are classified, not just the drawings.

Design changes during construction under the building contract

Towards the builder, all design changes during construction are changes to the contract. The Italian Civil Code covers them in three articles, which we read in their operative text and which anyone building a house in Italy should know before signing.

Agreed changes (Article 1659)

Article 1659 of the Civil Code states that the builder may not change the agreed manner of the work unless the owner has authorised it, and that the authorisation must be proved in writing. Even where the changes have been authorised, if the price of the whole work was set as a lump sum, the builder has no right to payment for the changes or additions, unless otherwise agreed. This is why a change order must state in writing whether, and how much, the change costs.

Necessary changes (Article 1660)

Article 1660 covers changes needed to carry out the work properly. If the parties do not agree, a court determines the changes to be made and the corresponding price adjustments. If the value of the changes exceeds one sixth of the total agreed price, the builder may withdraw from the contract and obtain, according to the circumstances, fair compensation. If the changes are considerable, the owner may withdraw and must pay fair compensation.

Changes ordered by the owner (Article 1661)

Article 1661 gives the owner the right to make changes to the project, provided their value does not exceed one sixth of the total agreed price. The builder is entitled to payment for the extra works even if the price was set as a lump sum. The rule does not apply when the changes, although within that limit, involve considerable modifications to the nature of the work or to the quantities of the individual categories of works in the contract.

Taken together, the three articles say that design changes during construction are facts to be documented: who asks for them, why, what they cost and how long they take. The construction specification (capitolato) can set out in advance the procedure, the unit prices to apply and the limits, as far as the law allows the parties to agree.

The site supervisor’s role in design changes during construction

Site supervision (direzione lavori) is where the two sides of a change meet. In our practice the site supervisor does not decide the change on the owner’s behalf but makes it possible to decide: he describes its consequences for the title, the structures, the price and the time, and brings it for signature only when all four answers are clear. A change that comes from the builder follows the same path as one requested by the owner.

The path we follow is this:

Request: whoever proposes the change (owner, builder, structural engineer, supplier) writes it down, with the reason.
Classification: the site supervisor establishes whether the change affects the building title, and which of the three routes applies, and whether it affects structures, protected areas and site safety.
Drawings: the design drawings are updated and, where necessary, the construction drawings.
Price: the builder prices the change with the contract rates or, for new items, with new rates checked by the supervisor against the bill of quantities.
Time: the effect on the construction schedule is measured, including the time needed for any application.
Change order: the owner signs a document containing all of the above.
Title: the required building application is filed within the time the rules require.
Execution and record: the change is built and recorded in the site diary and in the final drawings.

Design changes during construction and façade detail: perforated screen on SD Home in Soave, a project by the studio — SD Home, Soave (Verona): a detail from a project by the studio, shown as a reference of language, not as an example of design changes during construction.

The written change order: what it contains

Article 1659 requires written proof of the authorisation. In our practice the change order is the document that provides it and that keeps contract and building title aligned. A complete change order for design changes during construction contains:

a sequential number and date, with a reference to the building contract;
a description of the change and its reason, distinguishing between a change requested by the owner, a change needed to build properly and a proposal by the builder;
a list of the drawings modified, with their revision;
the planning classification: no effect on the title, variant by SCIA or variant to be authorised by permit, and who files the application;
the effects on structures and on any seismic filing or authorisation;
the price of the change, with the items of the bill, any new rates and the omitted works to be deducted;
the effect on the contract time, in days, and on penalties;
the signatures of owner, builder and site supervisor.

A change order without a price is incomplete. Under a lump-sum contract Article 1659 denies the builder payment for authorised changes unless otherwise agreed, while Article 1661 grants payment for changes ordered by the owner within one sixth. Writing the price into the order avoids having to decide later, perhaps in court, which of the two rules applies.

Effects of design changes during construction on cost and time

Design changes during construction have a direct cost, the price of the added works minus that of the omitted ones, and indirect costs that often weigh more: demolition of parts already built, materials ordered and no longer usable, idle crews, new supplies with long lead times, fees for applications and for structural recalculation. In our practice we list them separately, so that the owner assesses the change on its total cost and not only on the price of the item.

The same applies to time. A variant by SCIA may not stop the site; a variant that needs a permit, or one that needs landscape authorisation, may block the related works for the length of the review. This is why the same change costs less if it is decided earlier: moving a wall during the design process is an hour of drawing, on site it can be a demolition. On the overall cost of works see our guide on the cost of renovating a house in Italy.

Design changes during construction, structures and seismic zones

Changes that touch the structure are the ones that call for most care. Article 93 of Presidential Decree 380/2001 requires, in seismic zones, written notice to the municipal one-stop desk with the filing of the signed project and of the designer’s statement that the technical standards are met. Article 94-bis classifies works as relevant, of lesser relevance and of no relevance; for relevant works, construction may not start without prior authorisation from the regional technical office.

Paragraph 2 of Article 94-bis refers to guidelines of the Ministry of Infrastructure to identify, among other things, non-substantial variants for which the notice under Article 93 is not required. We have not read those guidelines or the regional rules that implement them, so we do not report their content.

The prudent rule is this: any change that modifies beams, columns, slabs, foundations, openings in load-bearing walls or loads goes to the structural engineer before it is built, and the filing or authorisation is updated where the rules require it. Article 32 lists among essential variations a breach of seismic rules that is not merely procedural.

Design changes during construction in protected landscapes

On properties in protected landscape areas there is an extra step. Article 146 of Legislative Decree 42/2004 forbids owners of protected assets to destroy them or to make changes that harm the protected landscape values, and requires them to submit their projects to the competent authorities and not to start works until authorisation has been obtained. Paragraph 4 of the same article states that the authorisation is valid for five years.

In practice, if a change alters the approved external appearance (façade materials, openings, roofs, external works), the landscape authorisation issued for the original design may not cover it. The sector rules provide exclusions and simplified procedures, which must be checked for each intervention. In our practice every change that affects the exterior of a protected property is checked with the designer before the change order is signed. The same reasoning applies to the hydrogeological constraint when a change alters excavations or earthworks.

Design changes during construction and site safety

A design change often also changes the works and how trades interfere with each other. Article 92 of Legislative Decree 81/2008, paragraph 1, letter b), requires the safety coordinator for the execution phase to update the safety and coordination plan and the building file in relation to the progress of the works and to any changes made, and to check that the contractors update their own operational safety plans.

On sites where a coordinator is appointed, design changes during construction that affect the works must be reported to the coordinator too. On the initial obligations see our guide on construction site safety in Italy.

Design changes during construction in interiors: dark reflective surfaces at MD Home in Verona, a project by the studio — MD Home, Verona: an interior from a project by the studio, shown as a reference of language, not as an example of design changes during construction.

End of works, habitability and lawful status

Design changes during construction do not end when they are built. Variant SCIAs under Article 22, paragraph 2, are part of the permit procedure also for habitability purposes; variants under paragraph 2-bis are reported at the end of works with the professional’s statement. If at the end of the site the built house does not match the filed drawings, the certificate of habitability (agibilità) cannot certify conformity.

The mismatch then surfaces at sale, when a professional reconstructs the lawful status of the property, as explained in our guide to the planning compliance check. Small differences may fall within construction tolerances; the others need regularisation, where it is possible. A change documented today avoids a regularisation file tomorrow.

Frequent mistakes in design changes during construction

Agreeing on site verbally: Article 1659 requires written proof of authorisation, and without a document nobody knows what was asked for and at what price.
Building first and filing later a variant that needs a permit, relying on a later regularisation.
Using a variant SCIA for changes in volume or parameters, which paragraph 2 excludes.
Forgetting the protection: on protected assets consent comes before works, and an essential variation counts as total non-conformity.
Touching the structure without the structural engineer, even for a «small» opening in a load-bearing wall.
Not pricing the change and discovering the cost in the final account, with a lump-sum contract to be interpreted.
Not updating the schedule, losing control of penalties and handover date.
Adding up many small changes without a register: together they may exceed one sixth of the price or change the nature of the work.
Not updating the final drawings, leaving a house that differs from the filed project.

Italian terms at a glance

Variante in corso d’opera: a design change made while works are under way.
Permesso di costruire: the building permit issued by the municipality.
SCIA (segnalazione certificata di inizio attività): a certified notice of start of works, filed by the owner with a professional’s statement.
CILA: a certified notice of works for lighter interventions, signed by a licensed professional.
Variazione essenziale: an essential variation, a change that the Region classifies as substantial under Article 32.
Totale difformità: total non-conformity with the permit, the most serious category of breach.
Direzione lavori: site supervision by the professional who directs the works for the owner.
Ordine di variazione: the written change order signed by owner, builder and site supervisor.

Frequently asked questions about design changes during construction

What are design changes during construction in Italy?

They are changes to the project decided during the works. They have a planning side, if they change the drawings attached to the title issued by the municipality, and a contract side, because they change the work agreed with the builder. Both must be handled in writing.

When can design changes during construction be made with a SCIA?

For building permits, when they do not affect planning parameters and volumes, do not change use and building category, do not alter the outline of protected buildings and do not breach the permit’s conditions (Presidential Decree 380/2001, Article 22, paragraph 2), or when they are not an essential variation and comply with the planning rules (paragraph 2-bis).

What is an essential variation?

It is a change that the Region identifies within the criteria of Article 32 of Presidential Decree 380/2001, among them a change of use that alters planning standards, a considerable increase in volume or floor area, substantial changes to parameters or position, and a non-procedural breach of seismic rules.

Do design changes during construction delay completion?

They can, if they add works or need applications. In our practice the change order states the effect on contract time in days, and the construction schedule is updated before the change is built.

Can the builder make a change without asking?

No. Under Article 1659 of the Civil Code the builder may not change the agreed manner of the work without the owner’s authorisation, which must be proved in writing. Changes needed to build properly are governed by Article 1660.

Who pays for design changes during construction under a lump-sum contract?

It depends on where they come from. With a lump-sum price, Article 1659 excludes payment for authorised changes unless otherwise agreed; Article 1661 grants payment for changes ordered by the owner within one sixth of the price. It is wise to write the price into the change order.

Is a new landscape authorisation needed for a change?

If the change alters the external appearance of a protected asset, the authorisation for the original design may not cover it, and works do not start before consent (Legislative Decree 42/2004, Article 146). Exclusions and simplified procedures must be checked for each intervention.

Checks on design changes during construction before signing the order

Before a change order is signed, design changes during construction should pass these checks.

Design changes during construction are described in writing, with the updated drawings and the reason for the change.
Design changes during construction are classified against the building title: no effect, variant SCIA or permit.
Design changes during construction are compared with the regional law on essential variations.
Design changes during construction on a protected property have the authority’s consent before they are built.
Design changes during construction that affect the structure are checked by the structural engineer, with the filing or authorisation updated where required.
Design changes during construction carry a written price, with added and omitted works.
Design changes during construction carry a written effect on time, in days, entered in the schedule.
Design changes during construction are reported to the execution-phase safety coordinator, if one is appointed.
Design changes during construction are recorded in the site diary and in the final drawings.
The total of all changes is compared with one sixth of the total contract price.