The problem: a boundary wall exceeding the legal height in Marseille
You notice that a wall built on the boundary of your plot towers well above your existing fence. Two questions arise immediately: is this wall party-owned (mitoyen)? And if so, does its height comply with the rules applicable in Marseille?
The Civil Code governs shared walls and boundary fences in Blog 653 to 673. Article 653 states that “in towns and suburbs, any wall separating buildings up to the roof line, or separating courtyards and gardens, and even enclosures in fields, is presumed to be shared (mitoyen) unless there is a title or evidence to the contrary”. In other words, a wall standing exactly on the boundary line is deemed to belong half to each neighbour, unless a title deed or proof of sole ownership shows otherwise.
Article 663 of the Civil Code sets minimum heights for shared boundary fences: 3.20 metres in towns of fifty thousand inhabitants or more – which includes Marseille – and 2.60 metres elsewhere. But this is a minimum: the local urban plan (PLU) can set different maximum heights per zone. When a wall exceeds the height allowed by the PLU, or when a unilateral raising oversteps the rights of the co-owners (Article 658(2): “Any owner may raise the party wall, but must alone bear the cost of the raising”), the affected owner has technical and legal routes to have the irregularity recorded and the wall brought into line.
Legal classification: party ownership and raising of the wall
The presumption of party ownership (Article 653)
If the wall stands exactly on the boundary line, it is presumed to be shared. This presumption can be rebutted by:
- a title of ownership (notarised deed, boundary survey) granting the wall to a single owner;
- marks of non-party ownership (Article 654: “There is a mark of non-party ownership when the top of the wall is straight and plumb with its face on one side, and presents an inclined surface on the other”).
In practice, the technical assessment starts with the title deeds and the cadastral plan. The firm asks the owner for the notarised deed, the building regulations (where they exist) and any earlier correspondence with the neighbour. These documents determine whether the presumption of shared ownership applies.
Unilateral raising and obligations (Blog 658(2) and 661)
Article 658(2) allows each co-owner to raise the party wall, provided they alone bear the cost and the upkeep of the raised section. Article 661 adds that a co-owner may acquire shared ownership of the raised part by paying half its cost and half the value of the land it occupies. But the raising must not exceed the maximum heights set by the PLU, nor cause damage to the neighbouring property (loss of sunlight, blocked views, extra load on the foundations).
If the wall exceeds the regulatory height in the PLU, the raising is irregular and amounts to a breach of planning rules. The affected neighbour can seek compliance, supported by the documents and expert reports establishing the excess.
Assessment method: measure, analyse, classify
Step 1: Preliminary documentary analysis
Before visiting, the firm reviews the photographs supplied, the cadastral plan, the PLU in force in Marseille and the available notarised deeds. This identifies the applicable PLU zone (U, AU, N…) and its maximum height rules.
Step 2: On-site survey
On site, the firm carries out:
- precise measurement of the wall height with a laser rangefinder, referencing the natural ground level on each side (a slope can distort the apparent height);
- a check of the wall’s position relative to the boundary (an offset can reveal an encroachment, which is a separate issue from party ownership);
- a search for marks of party or non-party ownership (chamfer, dressed face, sloping coping);
- annotated photographs and a dimensioned sketch.
Step 3: Review of the Marseille PLU
The Marseille PLU sets different maximum heights per zone. In some central districts, heights follow the street width or the adjoining cornice line; in lower-density residential zones, the ceiling can drop to around 7 metres. The firm checks the wall against the rules actually applicable to the plot – only this comparison settles whether there is a breach.
Step 4: Written report
The expert report sets out:
- the legal classification of the wall (party-owned, sole ownership, on the line or set back);
- the measured height and the applicable regulatory height;
- the extent of any excess;
- the practical consequences (lost sunlight, extra load, potential damage);
- the applicable liability regimes (strict liability under Article 1242 of the Civil Code in case of collapse, contractual liability where a servitude is breached, tort liability for abnormal neighbourhood disturbance).
Recourse: compliance and compensation
Amicable formal notice
The affected owner sends the neighbour a registered letter with acknowledgement of receipt citing Blog 653, 658 and 661 of the Civil Code and the applicable PLU rules, and demanding compliance within a reasonable time (usually thirty days). The expert report can be enclosed to objectivise the situation.
Applying to the judicial court
If there is no reply or a refusal, the claimant can apply to the Marseille judicial court. The claim can seek:
- a declaration that the wall is party-owned (Article 653);
- compliance works (partial demolition of the irregular raising);
- compensation for loss of enjoyment (lost sunlight, blocked view) where applicable.
The judge may order a contradictory court expert assessment to measure the wall precisely and establish its classification. Assessment costs are generally borne by the losing party. The judicial assessment settles the party-wall status, the exact height and each owner’s obligations.
Enforcement against planning breaches
If the wall exceeds the PLU’s maximum height, it is a planning offence (Article L. 480-4 of the Planning Code). The mayor can report the offence and seek compliance; the criminal court can impose a fine and order demolition or reinstatement at the offender’s expense.
Deadlines and the cost of inaction
Acting quickly has several advantages:
- while works are still under way, compliance is easier to obtain (masonry still open, height reducible before the coping is laid);
- after a certain time, the neighbour may invoke de facto tolerance or the absence of a proven disturbance;
- if the raised wall later supports a secondary structure (canopy, pergola), partial demolition becomes costlier and more complex;
- on a later sale, an irregular wall can amount to a hidden defect engaging your liability towards the buyer.
Physically, an oversized wall can – depending on Marseille’s soils, which include swelling clays in some districts – cause structural disorders (differential settlement, cracks) where the footings were not designed for the extra load.
Why an independent expert
An amicable expert assessment objectivises the situation before any litigation. It delivers a written, precise, contradictory report usable before the judge if needed. It avoids misclassification (a wall on the line is not always party-owned; a set-back wall never is) and the measuring approximations that would weaken your position.
Cassini Expertise works in Marseille and across the Bouches-du-Rhône on party-wall, encroachment and planning-compliance assessments. Our files are heard before the Marseille judicial court and, on appeal, before the Aix-en-Provence Court of Appeal.
Contact: Cassini Expertise – 22 rue Vauban, 06600 Antibes – Phone 04 22 46 06 04. We reply within 24 working hours and deliver the written report within 2 to 5 working days of the visit.
Frequently asked questions
What is the legal minimum height of a party wall in Marseille?
Article 663 of the Civil Code sets a minimum boundary-fence height of 3.20 metres in communes of 50,000 inhabitants or more – Marseille qualifies – and 2.60 metres elsewhere. This is a minimum that either neighbour can enforce; the maximum height is governed by the PLU.
My neighbour raised the party wall without my agreement: what can I do?
Article 658(2) allows a unilateral raising, provided the neighbour alone pays for the raised section and maintains it. The raising must not exceed the PLU’s maximum height nor cause damage. You can commission an expert survey to check compliance and, if necessary, apply to the Marseille judicial court for compliance works.
How can I prove that a wall is party-owned?
Article 653 of the Civil Code creates a presumption of party ownership for any wall standing on the boundary line. The presumption can be rebutted by a title deed or by marks of non-party ownership (Article 654). A technical assessment reviews the titles, measures the exact position and identifies any marks.
What recourse is there if the wall exceeds the height allowed by the PLU?
You can bring civil proceedings before the judicial court to obtain compliance (partial demolition) and, where applicable, damages. In parallel, you can report the offence to the mayor, who can draw up a report and start criminal proceedings under Article L. 480-4 of the Planning Code.
See also: Party Walls: The Rules Governing Shared Walls and Common Disputes · Shared Hedge in Nice: Height, Pruning & Planting Distance – Art. 671 Rules · Party Walls and Easements in the Alpes-Maritimes: The Technical Guide
Survey carried out by Frédéric Faucouneau, independent building expert – Antibes, Alpes-Maritimes (06), Var (83), Bouches-du-Rhône (13). Find out more
📅 Last updated 06/11/2026 - Cassini Expertise, independent building expert – departments 06, 83 and 13.