2. Trespass to common parts
What are common parts?
Under section 2 of the Building Management Ordinance (Cap. 344), the default position is that the whole building constitutes “common parts” except for areas specified in registered instruments, such as the Deed of Mutual Covenant (“DMC”), for the exclusive use, occupation, or enjoyment of a particular owner.
Schedule 1 of the Building Management Ordinance provides a non-exhaustive list of items commonly regarded as common parts, including external walls, lifts and staircases.
Whether a particular area (for example, a roof, a parapet wall, a light‑well or a parking space) is a common part therefore depends on the wording of the DMC and related title documents read together with the statutory definition.
Trespass on common parts happens when an owner, tenant, or outsider occupies, obstructs, or builds on shared areas without proper authority. Common examples include enclosing a public corridor to use as a private shoe cabinet area, building an illegal structure (such as a glass house) on a common roof and installing an unauthorised signboard on the building's external wall.
Three overlapping causes of action
Because all owners co‑own the common parts, and because building management is heavily regulated by the Building Management Ordinance, trespass disputes over common parts can give rise to 3 overlapping types of civil claims. The same set of facts is often framed under all three heads:
- Common law trespass;
- Breach of the DMC; and
- Contravention of section 34I of the Building Management Ordinance.
(i) Common law trespass
Trespass to common parts occurs when a person uses, occupies, obstructs or carries out works to those parts without proper authority under the DMC or without the consent of the co‑owners (acting through the Incorporated Owners or building manager). Examples include building an unauthorised structure on a common roof, enclosing a lift lobby as part of a shop, or treating a section of corridor as private storage space without approval.
(ii) Breach of the DMC
Common provisions of the DMC include prohibitions on structural alterations without consent, restrictions on changing the external appearance of the building, and covenants not to encroach upon or obstruct common parts. If an owner or occupier carries out works or uses the common parts in a way that breaches these covenants (for example, by knocking down structural walls, enclosing common lobbies or installing unauthorised signboards or canopies on external walls), the Incorporated Owners or the building manager may bring proceedings for an injunction and damages for breach of the DMC.
(iii) Contravention of section 34I of the Building Management Ordinance
Section 34I supplements the common law of trespass and the DMC by creating a statutory cause of action in respect of unauthorised conversion or unreasonable use of common parts. It explicitly provides that no person may:
- Convert any common part to their own use without the approval of the owners’ committee by resolution; or
- Use common parts in a manner that unreasonably interferes with other owners’/occupiers’ enjoyment, or causes a nuisance or hazard to anyone lawfully in the building.
Who can sue and be sued?
(i) Common law position
As a matter of common law, a co-owner cannot trespass on common parts in the ordinary sense, as each co-owner has a right of access thereto by necessary implication of their co-ownership. Each is entitled to use and enjoy the common parts concurrently with the others.
The one recognised exception arises where there has been an ouster. Where one co-owner physically excludes or expels another from possession of common parts, such as by fencing off parts of a roof or corridor and preventing others from entering, the ousted co-owner may bring a trespass claim and seek an injunction to be restored to possession.
By contrast, a non-co-owner, such as a tenant or a stranger, who uses, occupies, obstructs, or carries out works on common parts without proper authority is a trespasser in the ordinary sense and may be sued accordingly.
Where no Incorporated Owners have been formed, a single co-owner may bring an action against a non-co-owner for trespass to the common parts without the consent of the other co-owners.
(ii) Statutory modification under the Building Management Ordinance
In Hong Kong, the common law position is modified by the Building Management Ordinance. The Incorporated Owners have broad powers to prevent trespass and obstruction in common areas. Under sections 14, 16, and 18 of the Building Management Ordinance, the Incorporated Owners have both the statutory right and the duty to do all things reasonably necessary for the management of common parts and the enforcement of DMC obligations. DMCs typically impose corresponding obligations on the Incorporated Owners or the building manager to manage the common parts, including by preventing obstruction of common areas, removing unauthorised objects that interfere with the common parts, and taking enforcement action, including legal proceedings, against owners or occupiers who encroach upon or misuse the common parts.
Specifically, under section 16 of the Building Management Ordinance, once the Incorporated Owners are formed, the rights and duties of all owners in relation to the common parts are exercised by the Incorporated Owners as the body corporate representing all owners. The Incorporated Owners are accordingly the proper party to bring or defend proceedings concerning the common parts, such as actions in trespass, claims for breach of the DMC, or claims for contravention of section 34I of the Building Management Ordinance. An individual co-owner’s standing to bring proceedings against another co-owner in respect of the common parts is thereby displaced in favour of the Incorporated Owners.
Depending on the facts and the applicable legal basis for the claim, defendants in cases involving alleged trespass or misuse of common parts may include:
- individual flat owners who have enclosed, occupied or altered common parts without proper approval;
- tenants or licensees using common parts in breach of the DMC or section 34I of the Building Management Ordinance;
- landlords, who can be held jointly liable alongside their tenants if they permitted or authorised the tenant to encroach upon or misuse the common parts; and
- Incorporated Owners or building managers that have authorised or tolerated unauthorised uses of common parts contrary to the DMC or the Building Management Ordinance.
