Construction schedule in Italy: phases, durations, critical path, contract and site safety

A construction schedule is the document that says in which order a house is built, how long each task takes and which tasks depend on others. It looks like a calendar, but it is a design tool: it lines up decisions, deliveries, contractors, payments and inspections, and shows where a delay spreads to the whole site. For a new villa or a major renovation in Italy it is where the design meets real time, with its seasons, its lead times and its waiting periods.

This guide explains what a construction schedule is in Italy (the cronoprogramma dei lavori), how it is built for a house (phases, durations, dependencies, Gantt chart, critical path, lead times, weather), how it relates to the building contract, penalties, progress payments and the site safety plan, and how it is updated during the works.

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 and buyers. It is not legal advice or a binding technical opinion: the durations given are hypothetical examples, and every site must be scheduled on its own design.

Construction schedule in brief

A construction schedule lists tasks, phases and sub-phases, their sequence in time and their duration. This is the definition given in Annex XV of Legislative Decree 81/2008, point 1.1.1.
On sites that require a safety and coordination plan, the expected duration of tasks and phases, which forms the schedule, is a minimum content of the plan (Annex XV, point 2.1.2).
It is built from the construction drawings: without a defined design, quantities, supplies and durations cannot be estimated.
Dependencies matter more than durations. The critical path is the chain of tasks that, if delayed, moves the end of the works.
Windows, building services, prefabricated structures and made-to-measure finishes have ordering and delivery times that belong in the construction schedule before work starts.
Attached to the building contract, the construction schedule becomes the reference for penalties, progress valuations and payments; the site supervisor updates it and compares it with the real site.

Construction schedule for a villa: AV Home in Dueville at sunset with garden and pool, a project by the studio — AV Home, Dueville (Vicenza): a project by the studio shown as a reference of language, not as an example of a construction schedule.

What a construction schedule is in Italy

The term has a legal definition in the field of site safety. Annex XV of Legislative Decree 81/2008, point 1.1.1, letter g), in the text published in the Official Gazette in 2008 that we read, defines the cronoprogramma dei lavori as the programme that sets out, according to the complexity of the work, the tasks, phases and sub-phases, their time sequence and their duration. The annex has been amended several times, so the current text must be checked before it is quoted in a contract.

On site, the construction schedule has a wider use than the safety rule. It is the document through which designer, site supervisor (direttore dei lavori), contractor and client agree on time. It is used to plan deliveries, to set the dates of progress valuations and to decide when the client must choose floors, sanitaryware and kitchen. A house is built well when every decision arrives before the moment it is needed, and the schedule is the tool that makes that moment visible.

What a construction schedule is not

It is not a promise of a handover date: it is a reasoned forecast that depends on stated assumptions.
It is not a list copied from the bill of quantities: cost items and tasks to be scheduled do not always coincide.
It is not a one-off document: it is updated with real progress and with design changes.
It does not replace the design: if drawings and choices are missing, the schedule shows the gap rather than filling it.

The construction schedule and the time limits of the permit

Before the contract, the construction schedule has to fit within the time limits of the building permit. Article 15 of Presidential Decree 380/2001, in the current text we read, states that the building permit (permesso di costruire) sets the deadlines for starting and completing the works. The start may not be more than one year after the permit is issued, and completion may not be more than three years after the works begin.

Once those deadlines pass, the permit lapses for the part not carried out, unless an extension is requested before the deadline. An extension may be granted by a reasoned decision for supervening events beyond the holder’s control, or because of the size of the work or technical difficulties that emerged after work started. The unfinished part needs a new permit, except where a certified notice is enough. Later laws have provided special extensions, which must be checked in the current text and with the municipality.

In our practice, the first line of the construction schedule is therefore the date of the permit, and the last line is compared with the completion deadline. On the permits needed to build or renovate, see our guides on the building permit in Italy and on CILA and SCIA renovation permits.

Where the construction schedule starts: drawings and quantities

A reliable construction schedule can be written only when the design is defined enough to know quantities and building solutions. The construction drawings say what is built and with which details; the bill of quantities says how much is built; the construction specification says under which rules. The schedule turns these three documents into time.

Durations are not invented. They come from quantities and from the productivity of the crews, which the contractor knows better than anyone. In our practice the studio prepares a first version of the schedule with phases and dependencies, and asks the tendering contractors to give their own durations on that structure. The bids then become comparable on time as well as on price, and the chosen contractor signs a programme it helped to write.

Typical phases in the construction schedule of a house

Every project has its own sequence, but for a new detached house the phases that appear in the construction schedule are usually these. For a renovation the list changes: surveys, demolition, structural checks on the existing building and, often, works carried out in parts are added.

Preliminary activities: building permit, the preliminary site notification where required, contracts, orders for long-lead supplies, site set-up.
Excavation and foundations: setting out, excavation, any retaining works, foundations, waterproofing and drainage.
Structure: basement if planned, load-bearing structure, floor slabs, roof.
Envelope: infill walls, roof covering, flashings, sub-frames, external windows and doors, shading systems.
First-fix services: chases, water and drainage networks, electrical distribution, ventilation, underfloor heating and cooling.
Rough finishes: screeds, plaster, external insulation and render, plasterboard.
Finishes: floors, wall tiling, painting, internal doors, sanitaryware, switches and sockets, light fittings.
External works: landscaping, fences, pool, paving, planting.
Testing and close-out: services testing, certificates, cleaning, final inspection, documents for the certificate of habitability.

Each phase then breaks down into sub-phases. The right level of detail is the one that shows who works where and when. A construction schedule that is too summary hides overlaps between contractors; one that is too dense becomes impossible to update.

Durations and dependencies in a construction schedule

Every task has a duration and one or more relationships with others. The most common is «finish-to-start»: internal plaster begins when the service chases are closed. There are also «start-to-start» relationships, for tasks that can begin together a few days apart, and compulsory waiting times, such as the curing of a concrete pour or the drying of a screed before a moisture-sensitive floor is laid.

Technical waiting times are where optimistic schedules break. Curing and drying times depend on materials, thicknesses, season and site ventilation. They are given by the manufacturers’ data sheets and by the specification, not by a general rule. In our practice every technical wait appears in the construction schedule as a task of its own, with its source, so that nobody compresses it to recover a delay.

Constraints the construction schedule must show

tasks that cannot take place in the same space at the same time;
the arrival and departure of each contractor, with the dates on which each must be available;
choices the client must make by a given date (samples, colours, models);
material deliveries and the storage space available on site;
inspections, tests and checks that stop a task until the result is known.

Gantt chart and critical path

The most common form of construction schedule is the Gantt chart: tasks are rows, time runs horizontally, and each activity is a bar as long as its duration. The chart makes the sequence readable even to non-specialists, which is why the studio attaches it to the contract. Dependencies are drawn as arrows between bars.

The critical path is the chain of linked activities that sets the overall duration: if one of them is a week late, the end of the works is a week late. Activities outside the critical path have float, meaning they can slip within a limit without moving the handover. Knowing where the critical path runs tells the site supervisor where to concentrate attention and where a small delay can be tolerated.

In a house the critical path often runs through the structure, the closing of the envelope and the services, because internal finishes cannot start until the building is weathertight and the networks are in place. It is not a rule, though: a made-to-measure window with a long production time, or a lift, can itself become the critical path of the construction schedule.

Long-lead supplies: windows, services, finishes

Many delays do not start on site but in purchasing. Large external windows, glazed façades, heat generators and service plant, lifts, steelwork, made-to-measure stone and timber, kitchens and fitted joinery need surveys, supplier shop drawings, approval and production. Each of these steps belongs in the construction schedule, counted backwards from the date on which the item is needed on site.

Lead times are declared by suppliers when the order is placed and they change over time. We do not quote any in this guide because no value is valid in general. In our practice the method is as follows:

list the long-lead supplies already in the construction drawings;
ask suppliers, with their quotation, for drawing, approval, production and installation times;
set in the construction schedule the latest order date for each supply;
schedule the on-site survey, where the supplier requires it, as a task that depends on the structure;
have the client sign off finish choices by dates given in the programme.

A frequent case: a window can be surveyed only once its sub-frame is fixed, but the house can be closed only once the windows are installed. If production is long, it is worth considering temporary closures or a different order of internal work, and writing that into the construction schedule instead of discovering it on site.

Seasons and weather in the construction schedule

Weather is a constraint that is predictable in its pattern, if not day by day. Concrete pours, waterproofing, external render, external insulation, external painting, roofing and planting have temperature and humidity conditions set by manufacturers and by the specification. A construction schedule that places these tasks in the coldest or wettest months must allow margins, protection or alternatives.

In our practice, for sites in north-east Italy and Lombardy, we try to close the structure and envelope before the months in which external work is most exposed, so that work moves indoors when conditions outside are difficult. Days lost to bad weather are handled in the contract: it states how they are recorded (the site diary, giornale dei lavori) and whether they move the deadlines. The holiday closures of contractors and suppliers, which in Italy can be long in August and at Christmas, also go into the calendar from the start.

Construction schedule and finishes: living room opening onto the pool at SD Home in Soave, a project by the studio — SD Home, Soave (Verona): interiors and exterior of a project by the studio, shown as a reference of language, not as an example of a construction schedule.

A construction schedule example with invented figures

The example below uses invented durations. It does not describe a real site and it is not a benchmark for building a house. It shows how sequence, dependencies and critical path are read in a simplified construction schedule.

Site set-up: 2 weeks (assumption).
Excavation and foundations: 6 weeks, after set-up.
Structure and roof: 14 weeks, after the foundations.
Window order: placed in week 4, with a time declared by the supplier, in this hypothesis, of 16 weeks for sub-frame survey, production and delivery.
First-fix services: 8 weeks, which may begin once the roof is closed.
Window installation: 2 weeks, after delivery.
Screeds and plaster: 6 weeks, plus a drying period set by the specification before timber floors are laid.
Finishes and testing: 12 weeks.

In this example the structure ends in week 22. If the sub-frames can be fixed only once the structure is complete, the window survey slips and delivery arrives later than the week-4 order suggested: the windows enter the critical path. The answer is not to squeeze the finishes but to decide earlier: fix sub-frames where the structure allows, or agree with the supplier on a survey from drawings. Read properly, the same construction schedule changes the order of decisions.

The construction schedule in the safety and coordination plan

On sites where more than one contractor works, even at different times, Article 90 of Legislative Decree 81/2008 requires the client or the client’s project manager to appoint a safety coordinator for the design stage when the design is commissioned, and a safety coordinator for the works before the works are awarded. The same article asks that the expected duration of the various works or phases be taken into account at the design stage. On the wider topic see our guide on construction site safety in Italy.

Article 100 states that the safety and coordination plan (piano di sicurezza e coordinamento, PSC) is an integral part of the building contract and that its minimum contents are set out in Annex XV. In the 2008 text of Annex XV that we read, point 2.1.2, letter i), lists among the minimum contents the expected duration of tasks, phases and, where the complexity of the work requires it, sub-phases, which make up the construction schedule, together with the estimated size of the site expressed in man-days.

Interference and staggering

Under point 2.3.1 of the same text, the design-stage coordinator analyses interference between tasks, including those carried out by the same contractor or by self-employed workers, and prepares the construction schedule. Point 2.3.2 requires the plan to set operating rules for staggering interfering tasks in space or in time. Point 2.3.3 provides that during the works the coordinator for the works periodically checks, after consulting the site supervisor, contractors and self-employed workers, that the plan is compatible with progress, and updates the schedule if necessary.

Article 92 gives the coordinator for the works, among other duties, the task of adapting the plan to the progress of the works and to any changes, and of suspending individual tasks in the event of serious and imminent danger directly observed. Under Annex XV (points 4.1.1 and 4.1.4 of the text read) safety costs are estimated for the whole duration of the planned tasks and are not subject to discount in bids. In practice, the contractor’s construction schedule and the one in the safety plan should be the same document, or at least consistent.

The construction schedule, the building contract and penalties

Attached to the contract, the construction schedule stops being a forecast and becomes a commitment. In contract practice for private houses, the building contract (contratto d’appalto) states the start date, the completion deadline, any intermediate milestones and the consequences of delays. We do not summarise the Italian Civil Code rules on building contracts here because we could not read the text at source: the contract should be drafted with a lawyer, who checks it against the law.

Penalty clauses are the most debated part. In our practice we advise tying them to a few clear, measurable milestones (envelope closed, services complete, completion), not to every bar of the chart, and writing into the contract the causes that move deadlines without penalty: changes requested by the client, late decisions, suspensions ordered for safety, events recorded in the site diary. A penalty that applies to everything ends up applied to nothing.

Progress valuations and payments

The progress valuation (stato di avanzamento lavori, SAL) is, in practice, the periodic account of the work carried out, prepared or checked by the site supervisor and used for interim payments. The construction schedule makes it possible to forecast when valuations will fall due and to plan the client’s cash flow. Two common models are payment by percentage of work done, measured against the bill of quantities, and payment by schedule milestones. In both cases payment follows inspection, not the date.

Site supervision: how the construction schedule is updated

During the works the site supervisor compares the programme with real progress. In our practice the update is periodic and written: the status of each task is recorded, the critical path is recalculated, and the causes of any deviation and the actions decided are noted. The original schedule is kept as a baseline, and each later version carries a date and a number, so that at the end of the works one can reconstruct why the timing changed.

The most common reasons for an update are design changes, late choices, late deliveries, weather and surprises in existing buildings during renovations. Changes to the design during the works affect the permit, the price and the time; our guide on design changes during construction covers them. A change is never just a drawing: it should always come with its effect on the construction schedule, discussed before it is approved.

Control tools

a regular site meeting with contractor and coordinator, with minutes and an updated schedule;
the site diary, recording attendance, weather, deliveries and stoppages;
a list of decisions awaited from the client, with the date by which each is needed;
the status of long-lead supplies: order, approved drawings, production and delivery dates.

The construction schedule in a renovation

In the renovation of an existing house the construction schedule carries more uncertainty than in new construction. Demolition and stripping out may reveal structures different from those expected, services to be replaced, damp, or discrepancies with the permits on file. In our practice the first weeks are scheduled as an investigation phase, with a checkpoint after which the programme is confirmed or revised, and the contract states that this review is planned.

If the house remains partly occupied, the programme is divided by zones, with separate access routes and noisy work concentrated at agreed hours. When the renovation involves a change of use or splitting a property into separate units, the time needed for the applications becomes part of the construction schedule. On renovation budgets see our guide on the cost of renovating a house in Italy.

Construction schedule and building detail: overhead daylight from a roof window at Villa Lonigo, a project by the studio — Villa Lonigo: a detail from a project by the studio, shown as a reference of language, not as an example of a construction schedule.

Frequent mistakes in a construction schedule

Writing it before the construction drawings: without quantities and details, durations are guesses.
Using standard durations found elsewhere instead of those declared by the contractors for that project.
Forgetting technical waiting times for curing and drying, which then get compressed.
Not scheduling orders for long-lead supplies, which become the critical path without anyone noticing.
Ignoring the client’s decisions: a tile chosen late stops the site just as a missing delivery does.
Overlapping contractors in the same space without checking the interference analysis of the safety plan.
Ignoring seasons and holiday closures of contractors and suppliers.
Tying penalties to every task, which makes them unenforceable in practice.
Not updating it: a construction schedule frozen at contract signature is of no use after the first month.
Running past the permit deadlines without requesting an extension in time.

Italian terms at a glance

Cronoprogramma dei lavori: the construction schedule, the programme of tasks, phases, sequence and durations.
Piano di sicurezza e coordinamento (PSC): the safety and coordination plan, part of the building contract where required.
Coordinatore per la progettazione / per l’esecuzione: the safety coordinator for the design stage and for the works.
Direttore dei lavori: the site supervisor appointed by the client, who checks the works against the design.
Contratto d’appalto: the building contract between client and contractor.
Stato di avanzamento lavori (SAL): the progress valuation used for interim payments.
Giornale dei lavori: the site diary.
Permesso di costruire: the building permit, which sets start and completion deadlines.

Frequently asked questions about the construction schedule

What is a construction schedule in Italy?

It is the programme that sets out the tasks, phases and sub-phases of a site, their sequence in time and their duration. The definition is in Annex XV of Legislative Decree 81/2008 (point 1.1.1); in practice it is also used to plan deliveries, payments and the client’s decisions.

Who prepares the construction schedule?

On sites with more than one contractor, the design-stage safety coordinator prepares the schedule within the safety plan (Annex XV, point 2.3.1, in the text read). In our practice the designer prepares its structure and the contractor adds its own durations; the site supervisor updates it during the works.

Is a construction schedule compulsory for a private house?

It is a minimum content of the safety and coordination plan, which is needed when more than one contractor works on the site. Even where it is not required, it is prudent to attach it to the building contract, because it is the reference for deadlines, penalties and payments.

How long does a villa take according to a construction schedule?

There is no duration that is valid in general: it depends on the design, quantities, contractors, supplies and the season in which work starts. The permit sets the outer limits: for a building permit, completion may not be more than three years after the start, unless extended (Presidential Decree 380/2001, Article 15).

What is the critical path in a construction schedule?

It is the chain of linked activities that sets the total duration of the works: a delay on any of them moves the end date. Other activities have float and can slip within limits without affecting handover.

How are the construction schedule and progress payments linked?

The schedule makes it possible to forecast when progress valuations (SAL) will be reached. In practice these are the periodic account of work done, checked by the site supervisor. Payment follows the inspection of the work, not the date written in the programme.

Can the construction schedule change during the works?

Yes, and it should be done in writing. The site supervisor updates it with real progress, and the safety coordinator for the works updates the one in the safety plan if necessary (Annex XV, point 2.3.3). Changes that affect contract deadlines must be agreed between the parties.

Construction schedule checks before signing the contract

Before signing a building contract, every construction schedule should pass the checks below.

The construction schedule starts from approved construction drawings and quantities, with date and version.
The construction schedule respects the start and completion deadlines of the permit.
The construction schedule shows dependencies and the critical path, not only bars.
The construction schedule contains the latest order dates for long-lead supplies, with the times declared by suppliers.
The construction schedule shows technical waiting times for curing and drying, with their source.
The construction schedule lists the decisions expected from the client and the date by which each is needed.
The construction schedule is consistent with the one in the safety plan and with the interference analysis.
The construction schedule allows for seasons and for the closures of contractors and suppliers.
The construction schedule attached to the contract identifies the few milestones tied to penalties and the causes that move deadlines.
The construction schedule states how often it is updated and who signs each new version.