WA: Does a strata company have a say over a granny flat?

Question: Does the strata company have any say over an owner building a granny flat in their private rear garden?

We are a six-unit self-managed strata scheme. Everything to the front of our buildings is designated common property. At the back of each unit, owners have their own private garden, individually fenced with a rear gate opening onto a common pathway.

One owner, who is currently renting his unit, wants to build a granny flat in his rear garden. Council no longer requires building permission, but building codes are still in place. The flat itself will be small and, being at the rear, will have little visible impact.

However, the remaining owners have concerns about parking. We currently have two spaces per unit and three visitor spaces, and worry that if other owners follow suit, parking will overflow onto the street.

Do we have any authority over this under the Strata Titles Act 1985?

Answer: Yes, a granny flat in the rear garden is likely a structural alteration requiring approval.

The Owner is making a structural alteration to their lot. Therefore, under the Strata Titles Act, alterations on lots are regulated under sections 86-90 and Regulation 75 ST(G)R 2019.

Regulation 75 details the requirement of the “Application for approval of structural alteration” and the following information is prescribed (required):

1. plans and specifications for the structural alteration;
2. the additional information prescribed for the type of structural alteration concerned by this regulation:
   1. the plot ratio restrictions and open space requirements in relation to the parcel;
   2. the pro rata entitlements of the lot (calculated as provided for by regulations 7 and 8);
   3. if the application is approved, the area of the structure, including the area of all existing and proposed structures to be taken into account for the purposes of calculating the plot ratio restrictions and open space requirements;
   4. whether or not the carrying out of the proposal will breach the pro rata entitlements of the lot and, if it does, the percentage and area by which the pro rata entitlements of the lot is exceeded;
   5. the location and dimensions of the proposed structure upon its completion in relation to any existing structure on the lot or to the boundaries of the lot;
   6. any contravention of the by-laws of the strata company, whether of a permanent or temporary nature, which is likely to occur during or as a result of the erection, alteration or extension of the structure, and any proposed manner of dealing with that contravention;
   7. any likely interruption to or interference with any statutory easement, short form easement or restrictive covenant or any other easement or restrictive covenant affecting the parcel that is shown on the scheme plan or registered against the parcel, whether of a permanent or temporary nature;
   8. whether the structural alteration of the lot changes the boundaries of the lot and whether the applicant has sought advice from a licensed surveyor about the effect of the structural alteration.

Once the application is provided to the strata company as per the prescribed requirements above, the approval is then to be provided under the requirements of sections 86 to 90 of the Act, which include:

Section 87 & Section 88: Approvals for structural alterations

• Section 87: Outlines the procedure an owner must follow when seeking approval from the strata company to structurally alter their lot. This section notes that the owner of a lot in a strata scheme must not cause or permit the structural alteration of the lot except: (a) with the prior approval, expressed by resolution without dissent, of the strata company or (b) if: (i) the prior written approval to the structural alteration has been given by the owner of each lot in the scheme,
• Section 88: Details the conditions under which the strata company can grant or withhold this permission, ensuring that the structural integrity and aesthetic consistency of the scheme are maintained.

This post appears in the August 2026 edition of The WA Strata Magazine.

Jamie Horner
Empire Estate Agents
E: JHorner@empireestateagents.com
P: (08) 9262 0400