Are Windows Common Property or Lot Property?

A Detailed Guide for NSW Self-Managed Strata Schemes

Windows are one of the most misunderstood components in a strata scheme. When leaks, corrosion, drafts, cracks, or replacement questions arise, committees often struggle to determine who is responsible — the lot owner or the Owners Corporation.

In NSW, the rules are far clearer than most people expect. This guide explains how window ownership works, the legal basis behind it, and the limited exceptions you need to check before assigning responsibility.

1. The Legal Rule: Windows Are Usually Common Property

Under the Strata Schemes Management Act 2015 (NSW) and NSW Land Registry Services boundary rules:

Windows — including frames, sashes, and seals — are common property unless the strata plan specifically says otherwise.

This means the Owners Corporation is responsible for:

• repairing windows
• replacing windows
• addressing leaks and drafts
• fixing corrosion or deterioration
• maintaining waterproofing around frames

Owners are only responsible for internal, non-structural items.

2. Why Windows Are Common Property

Windows sit within boundary walls, not within the lot interior.

In most strata plans:

The lot boundary is the inner surface of walls, floors, and ceilings.

Everything beyond that surface — including window frames and their structure — is common property.

That includes:

• window frames
• sashes
• glazing (glass panels)
• drainage channels
• seals and waterproofing
• external trims

These components affect building waterproofing, façade appearance, and structural integrity, which is why they fall under the Owners Corporation.

3. What the Lot Owner Is Responsible For

Even though windows are common property, owners remain responsible for items that are inside or purely cosmetic:

• flyscreens
• blinds and curtains
• internal repainting
• window cleaning
• cosmetic internal trims
• damage they personally cause

Example:

If an owner accidentally cracks a window during renovation, they pay for the repair — even though the window itself is common property.

4. The Three Exceptions — When Windows May Not Be Common Property

While most windows are common property, there are three legitimate exceptions.

Exception 1 — The Strata Plan Assigns Ownership to the Lot

Rare, but possible in older or unusual plans.

If the plan shows the window inside the lot boundary, the owner is responsible.

Exception 2 — A Registered By-Law Transfers Responsibility

A common property rights by-law can shift responsibility for:

• repair
• replacement
• maintenance

from the Owners Corporation to the lot owner.

The by-law must be:

• passed by special resolution, and
• registered with NSW Land Registry Services.

Exception 3 — The Window Is Completely Inside the Lot

Seen in:

• internal atriums
• enclosed balconies
• windows facing an interior space rather than the external façade

Since these are not boundary structures, they belong to the lot.

These situations are uncommon, but committees should check before making decisions.

5. Who Pays For Common Window Problems?

Windows are critical waterproofing elements, so most defects fall to the Owners Corporation.

6. Insurance and Windows

Strata building insurance generally covers:

• window frames
• glazing
• storm damage
• accidental breakage (not caused by the lot owner)
• structural window components

Owner contents insurance usually does not cover windows, unless they are entirely inside the lot (rare).

Incorrectly classifying windows can lead to insurance rejections — a common problem in self-managed schemes.

7. Window Renovations: What Requires a By-Law?

If an owner wants to modify or replace windows, the committee must follow the correct approval pathway.

Like-for-like replacement

Still affects common property → requires a by-law and special resolution.

Changing appearance

Tinting, different frames, or new style windows → always requires a by-law.

Installing a new opening

Structural changes → by-law + special resolution + engineering.

Committee cannot approve window alterations alone

Windows are structural elements.

They cannot be approved under the minor renovation pathway (Section 110).

8. Why Do Committees Often Get This Wrong?

Common causes include:

• relying on myths from previous committees
• assuming “it faces my unit, so it must be my responsibility”
• misunderstanding lot boundaries
• not checking the strata plan
• not realising waterproofing is involved
• incorrect advice from trades without strata knowledge

But the law has been consistent for decades:

Windows are common property unless the scheme has a by-law or strata plan proving otherwise.

9. How to Confirm Whether Windows Are Common Property

Use this quick process:

Step 1 — Check the Strata Plan

Look for boundaries and annotations.

Step 2 — Apply the Standard Boundary Rule

If the lot boundary is the inner wall surface, the window is common property.

Step 3 — Review By-Laws

Look for exclusive-use or responsibility-transfer by-laws.

Step 4 — Check Building Age

Older buildings rarely assign window responsibility to owners.

Step 5 — When in doubt, treat windows as common property

This avoids insurance and compliance issues.

Final Thoughts

For most NSW strata schemes, windows are without question common property.

This means the Owners Corporation must maintain them — including frames, seals, waterproofing, and structural components.

Clear classification helps avoid disputes, ensures repairs are properly funded, and keeps the building compliant and watertight — especially important for self-managed committees.

Strata On Demand Can Help

Strata On Demand provides professional support for self-managed schemes across NSW, offering 30+ services designed to simplify your workload, reduce risk, and deliver professional documentation without the cost of a full-service strata manager.

No contracts. No full-service strata manager fees.

Pay only for the services you need, when you need them.

For window repairs, window approvals, and common property decisions, the five most relevant services we offer are:

1. Quote Request Coordination

We source multiple quotes for window repairs, replacements, waterproofing issues, and façade works — saving your committee significant time.

2. Work Order Management

Once a contractor is chosen, we coordinate access, issue the work order, follow up progress, and confirm completion.

3. By-Law Drafting, Lodgement & Review

Required for any window alterations, upgrades, or like-for-like replacements. We prepare and lodge the by-law from start to finish.

4. AGM / EGM Agenda Drafting

We prepare compliant motions for window replacement, structural works, or by-law approval, ensuring your meeting notice is legally sound.

5. AGM / EGM Meeting Chairing

If window decisions are sensitive or complex, we chair your meeting professionally to ensure a fair, structured, and compliant process.

If your scheme needs clarity around window responsibility or help managing window repairs or approvals, contact Strata On Demand now.