Common Property in a Strata Scheme

A strata scheme generally consists of both lot property and common property. This article will look at what each of these are and what rights and obligations exist in relation to them. There are many ways in which common property rights can be affected but this article will look specifically at exclusive use by-laws.

Who owns and is responsible for what?

Lot property

Lot property is the part of the property comprised within a lot that is owned exclusively by a proprietor or proprietors. A lot is generally defined by its vertical and horizontal boundaries (i.e., its floor, ceiling, and walls) determined by reference to a scheme plan.

A scheme plan is a document lodged upon registration of a strata titles scheme that marks out the boundaries of each lot, including any car spaces, storage areas and other areas owned by the relevant lot.

Though it can be amended by the type of scheme plan and the notations on it, the general position is that the lot property commences from:

  1. the inner surface of the external boundaries;
  2. the upper surface of the floor; and
  3. the undersurface of the ceiling.

As a general rule, this means that everything inside the lot belongs to the relevant proprietor, including light fittings, light switches, power points, blinds, curtains, internal walls (i.e., walls not shown on the strata plan), shower and bath fittings, cupboards, and applications.

Additionally, utility conduits (such as electrical wiring and water pipes) for the exclusive use of one lot will form part of the lot.

The lot owner is generally responsible for the repair and maintenance of the lot property.  

Common property

The common property consists of all the property that is not comprised within a lot and is owned by all the lot owners in proportion to their unit entitlements. Upon registration of a strata scheme, it will be given an aggregate of unit entitlements that will be apportioned on, generally speaking, the value of each lot. This means that each lot will have an allocated amount of unit entitlements that go towards:

  1. the liability it has to contribute towards the strata company’s costs (such as repair and maintenance);
  2. in some cases, the lot owner’s voting rights; and
  3. the interest it ultimately has in the common property.

The interest a lot owner has in the common property, however, is indivisible which effectively only grants them a right to the use and enjoyment of the common property, subject to any by-laws and other lawful restrictions.

The common property will generally consist of common spaces, driveways, structural walls, original flooring, tiles, and a waterproofing membrane under the tiles, along with shared utility conduits such as water pipes and electrical wiring.

The strata company is responsible for the repair and maintenance of the common property.


In Western Australia, there are, broadly speaking, two types of by-laws.

The first is conduct by-laws, which deal with the conduct of occupiers and other people in the strata scheme and the management, control, use, or enjoyment of a lot or common property in the strata scheme.

The second is governance by-laws, which deal with the governance of the scheme and the exclusive use of the common property.

For example, a conduct by-law may prevent smoking on common property, while a governance by-law may detail the process for electing members of the council of owners.

For the purposes of this article, exclusive use by-laws (which are types of governance by-laws) are the most relevant. Exclusive use by-laws provide a lot owner or owners (and, by extension, the occupiers from time to time) exclusive use or special privileges over common property and the terms on which that use is to occur.

Sometimes, the special privileges or exclusive use conferred by the by-law can be obvious, such as the use of a storage area designated as common property. What is less obvious is that these by-laws are extremely important for any work which affects common property. This can include work such as:

  1. the installation of air-conditioning units affixed to common property (i.e. external walls or flooring);
  2. the installation of an aerial antenna affixed to the roof;
  3. the removal of a structural wall; and
  4. the installation of flooring.

It is extremely important to note that, generally, lot property will commence from the inner surface of external boundaries, the upper surface of the floor, and the undersurface of the ceiling.

Most work undertaken will affect common property in some way, including the potential for damage to arise from the removal of any works such as affixing underlay to the original floor.

An exclusive use by-law protects both the strata company and the lot owner because:

  1. it allows a lot owner to prove that he or she was authorised to undertake the work and as the by-law is registered with Landgate, this can be proven by a subsequent owner;
  2. if the work is shown to be authorised, the strata company is not able to compel the owner to remove the work undertaken or to remove the work itself; and
  3. the by-law will specify any terms the lot owner and the strata company agree to, such as who has the repair and maintenance, the obligations of the work, and what happens if damage arises as a result of that work.

It is also important to understand how these by-laws are prepared, voted upon and registered.

If you are a lot owner thinking about undertaking work in your lot or a strata company wanting advice on work proposed by a lot owner, we would be more than happy to assist with any queries.