Notre-Dame: on budget, on time, and what made it possible
Lidl had stopped its project part-way, and Revlon paid for its go-live for months. Notre-Dame ends well. In May 2022, its restoration was costed at €552 million, including €125.4 million of contingencies set aside by risk. The cathedral reopened on 8 December 2024, on the scheduled date, and part of the contingencies was never used.
Author
Tudor HilcuFounder & CEO, THG Conseil
Published
Reading time
10 min
Topics
Projects, Budget, Governance
Contents10
On 15 April 2019, Notre-Dame de Paris caught fire. That same evening, the French President set a goal: rebuild the cathedral in five years. On 8 December 2024, it reopened for worship and to visitors. In its report published on 3 September 2025, France’s Court of Audit, the Cour des comptes, found that the restoration work had been carried out in line with the schedule and the budget set.
The figures below come from that report. In May 2022, the public body in charge of the project set the cost of the restoration phase at €552 million. That amount included €125.4 million of contingencies, split into three lines: €66.5 million for price rises, €38.63 million for risks and unforeseen events, and €20.22 million for schedule risk. Not all of it was used. Once the work was done, at least €140 million of donations remained, which the major donors agreed to put towards a new phase of restoration.
This is case study no. 03 in my LinkedIn series, published the day after the Revlon case. A project that holds both its budget and its date is rare enough to look at how it was done.
A body set up for the project
Normally, restoring a state-owned historic monument falls to the Ministry of Culture’s own services, here the regional cultural affairs directorate for Île-de-France. For Notre-Dame, the state set up a dedicated public body to act as the client for the fire-related works. It recruited the profiles it needed and adjusted them as the project went on, without going over the operating budget set by its supervising ministry.
The Court points to two other strengths. The five-year goal, stated and restated right to the end, created a collective obligation for everyone involved. And the money was known early: donations, which quickly settled at around €840 million, gave unusual visibility over the resources available. On the organisation, its conclusion is clear: setting up a dedicated body to run the project proved a sound choice.
Contingencies set aside by risk, then tracked
The schedule line was there to hold the 2024 deadline if needed. The body’s audit committee compared three scenarios, setting the cost of a longer project against the cost of the measures taken to hold the date. Its conclusion, in November 2022: holding the schedule would cost less, whatever happened, than letting it slip.
The roof timbers are a case in point. The wood given by a donor was not dry enough. Waiting for it to dry would have extended the project by six months, at an estimated cost of €50 million. The public body decided to buy timber from the National Forestry Office (ONF) instead.
At the end of 2022, the lines for unforeseen events and for the schedule were merged, as the audit committee regarded them as interchangeable. By the end of 2024, this combined line was 83% used, or €49 million out of €58.8 million. The price-rise line, tracked at €70.8 million, was 75% committed, as inflation turned out lower than expected.
The tracking also went into the detail. According to the audit committee, €20 million of additional spending came from design flaws or programme changes made during the works. One of them, a large technical gallery on the south side, was proposed by the design team a few weeks before the tenders, when it could have been planned from the 2021 and 2022 design studies. The public body told the design team it was responsible, and refused the extra fee requested by the gallery’s designer.
A committee that looks closely at the figures
The audit and investment committee reports to the public body’s board. It is chaired by a recognised specialist in running public construction projects on the client side, and the Court stresses how active it was from start to finish. Before approval, it reviews contracts above €2.5 million excluding VAT for supplies and services, and above €10 million excluding VAT for works. From 2022, it also asked to see the results of tenders below those thresholds.
It flagged the same issue as the Court: contract amendments, meaning additional orders placed with firms already appointed. On this project, they could reach 46% of a contract’s original value, and two cases went beyond 50%. They drew on the contingency for unforeseen events, often because the initial estimate differed from the signed price. The study the committee asked for shows gaps in both directions and, for restoration contracts, points to “the weaknesses of the prior estimates”.
From September 2020, at the request of the foundations collecting the donations, among others, the public body also brought in a construction economist. The role: cost the work and make sure the budget and deadlines were met. With this support, the body could discuss works estimates closely with the chief architect, who led the design team.
The Court sums up how the budget was held: it “results from rigorous monitoring by the client and the design team, with strong involvement from the audit committee and close attention from the foundations”.
What slipped
Not everything reopened on 8 December 2024. Visits to the towers were due to resume the same day; they resumed on 20 September 2025. The visitor route had to be redesigned at the request of the safety commission, and defects found late in the south belfry required extra work. Roofing work on the spire also continued into 2025, with the cathedral open.
The same discipline, at SME scale
An SME does not restore cathedrals. But when it opens a workshop or changes software, it too has a budget, a date and unforeseen events. Often, those unforeseen events sit on a single “miscellaneous” line, with no justified amount and nobody answerable for it. Notre-Dame’s habits, on the other hand, scale down well.
Five practices to take on
One contingency per risk, with its amount and its owner. Price rises, unforeseen events, delay: one line each, costed, with the name of the person who can commit it. Using a contingency for a different risk takes a written decision.
A single body answerable for the project. One person or a small team holds the budget, the date and the contracts, and reports to the business owner. When three departments share a project, variances pass from one to the next and nobody stops them.
An outside eye on the figures. A partner, a board member, a peer or your accountant: someone who is not running the project. Set a threshold; above it, the spend is shown to them before signature.
Cost the delay before you decide. On one side, what an extra month costs; on the other, what holding the date costs (extra people, a pricier purchase, work done in parallel). The decision is made on both figures, as Notre-Dame’s committee did with its three scenarios.
Count the amendments. For each contract, note the gap between the estimate and the signed price, then each additional order and its reason. That is often where the contingency drains away. If your supplier should have foreseen a change, check what your contract says with your lawyer and your accountant.
Fictitious example, in thousands of euros: the contingencies of an SME opening a second workshop, halfway through
Risk
Planned
Used
Left
Prices
20
12
8
Unknowns
25
19
6
Delay
15
0
15
Total
60
31
29
A budget of €400,000, including €60,000 of contingencies. Each line has its owner: the purchasing manager for prices, the project manager for unknowns, the managing director for delay.
Halfway through, the delay line has not been touched, and the project manager would like to use it for an option requested along the way. The rule written at the start prevents it: the option goes to the committee, with its own costing. Without that rule, the delay line would have paid for the option, and the first real delay would have had nothing left to cover it.
What I learnt
On The Walt Disney Company’s ERP and WMS programme, I held the budget working directly with financial control: forecasts, accruals, sign-offs, payments, receipts. At Monoprix, I produced a budget report every week for the executive committee, with tools to spot overspend risks. On every assignment, I also negotiated supplier contracts, with the SLAs and quality assurance plans that make it possible to claim penalties.
In my projects, a line for “unforeseen costs” with no amount and no owner always ends up paying for something else. With a regular check-in between the project and financial control, you see it in the month it happens instead of finding out at year end.
The limits of this case
The figures are the Court of Audit’s, partly taken from the public body’s own tables. The €552 million covers only the fire-related restoration phase; the safeguarding phase before it accounted for around €150 million of additional work. The contingency lines of May 2022 were not tracked unchanged: two were merged at the end of 2022, and the price-rise line tracked at the end of 2024 (€70.8 million) no longer matches the original €66.5 million.
The date also moved before it was held: a reopening was at one point considered for the summer 2024 Olympic Games, before being set for 8 December. Lastly, the project enjoyed exceptional conditions, with large donations raised early and a goal backed at the very top of the state. An SME has neither, so I only draw lessons on how the project was run. I take no view on the gallery designer’s fee claim, which the public body rejected.
Where to start this week
Open the budget for your current project and find the “contingency”, “miscellaneous” or “margin” line.
Split it by risk: prices, unknowns, delay. Give each line an amount.
Next to each line, write the name of the person who can commit it, and the threshold above which they must ask you.
One hour’s work, and every line of your safety margin has an owner.
A contingency holds when it has an amount and an owner.
