Understanding the Invisible Boundary That Determines Ownership and Maintenance Responsibility

One of the most misunderstood concepts in South African sectional title law is the median line. Trustees, managing agents, and owners often find themselves debating who is responsible for repairing walls, windows, doors, ceilings, balconies, and other building components. In most cases, the answer lies in understanding where the median line is situated.

This blog explains what the median line is, how it is determined, and why it is important in the management of sectional title schemes.

What Is the Median Line?
The median line forms the invisible but inherent boundary that separates a section from common property or from another section.

In terms of Section 5(4) of the Sectional Titles Act 95 of 1986, the common boundary between a section and another section or common property is the median line of the dividing wall, floor, windows, doors including garage doors or ceiling.

Simply put, the median line generally runs through the middle of:

• Boundary walls
• Floors between units
• External doors, windows and garage doors
• Ceilings between units
• Structural divisions that separate sections and common property 

Everything inside the median line forms part of the owner's section, while everything outside the median line forms part of the common property.

Why Is the Median Line Important?
The median line determines:

a)     Ownership
It establishes what forms part of the owner's section and what forms part of the common property.

b)     Maintenance Responsibilities

It helps determine whether:

• The owner is responsible for maintenance and repairs; or
• The body corporate is responsible for maintenance and repairs.

How Is the Median Line Determined?

1. Walls
For a wall separating a section from common property or another section, the median line generally runs through the centre of the wall. However, the surveyor general plans should be checked to ensure this principle was used by the surveyor as there are exceptions to the rule.

2. Floors and Ceilings
In multi-storey buildings, the median line generally runs through the centre of the floor slab separating the units.

3. Doors and Windows
Historically, there was uncertainty regarding whether windows and doors belonged to the owner or the body corporate.

The Sectional Titles Amendment Act of 2010 clarified the position by providing that any window, door, or other structure dividing a section from common property is considered part of the dividing wall, floor, or ceiling.

As a result:

a)     The median line runs through the centre of the window or door.
b)     The inner half forms part of the section.
c)      The outer half forms part of the common property.

This often results in shared responsibility between the owner and the body corporate depending on the circumstances and scheme rules.

What About Balconies, Stoeps and Patios?
These areas frequently create confusion. The boundaries of projections such as:

a)     Balconies
b)     Stoeps
c)      Porches
d)     Atriums

may be specifically defined on the sectional plan and are not always determined solely by a median line.

Trustees should therefore consult:

• The registered sectional plan;
• Any approved amendments to the sectional plan; and
• The scheme's management and conduct rules.

How Can Trustees Determine the Median Line?

Step 1: Examine the Sectional Plan
The registered sectional plan is the primary source for determining boundaries and usually the surveyor will utilise the median line ruling.

Step 2: Identify the Relevant Structure
Determine whether the issue relates to:

a)     A wall
b)     A floor
c)     A ceiling
d)     A window
e)     A door; or
f)      Another boundary structure.

Step 3: Determine Which Side of the Median Line Is Affected

Question to ask:

Is the defect or maintenance item situated inside the section, outside the section, or does it affect both sides of the median line?

Common Mistakes Made by Trustees

Assuming Everything Inside a Unit Is the Owner's Responsibility

Structural components often remain common property even though they are physically located within a section.

Ignoring the Sectional Plan
Many disputes arise because trustees rely on visual inspections rather than the registered sectional plan.

Applying a Blanket Rule to Windows and Doors
The 2010 amendments clarified that windows and doors straddle the median line and therefore it was noted that the median line wavers, so the outside is common property while the inside is private property.

PRV Valves & Hot Water Installations
As per PMR 31 (1), the responsibility lies with the owner to maintain their hot water installation, with the installation normally falling under the body corporate building insurance. Where the installation is on common property, the owner must also maintain the Pressure Reducing Valve (PRV), however, where the installation falls within the owner’s section, then the body corporate must maintain the PRV if it falls on the common property.

31. (1) Notwithstanding that a water-heating installation forms part of the common property and is insured by the body corporate, a member must maintain, repair and, when necessary, replace such an installation which serves that members section or exclusive use area; provided that where such an installation serves sections owned or exclusive use areas held by more than one member, the members concerned must share the maintenance, repair and replacement costs on a pro-rata basis.

Therefore, if the hot water installation is installed on common property the owner is responsible for maintenance to the PRV, while if the hot water installation is installed in the owner’s section and PRV on common property then the body corporate would be responsible. You would also need to check the insurance cover to establish what cover is in place for this fixture.

Conclusion
The median line is one of the most important concepts in sectional title governance. Although it is invisible, it determines ownership boundaries, maintenance obligations, and often the outcome of disputes between owners and the body corporate.

When uncertainty arises, trustees should:

• Consult the registered sectional plan.
• Consider the location of the median line.
• Review the scheme's rules.
• Obtain professional advice from a sectional title specialist, architect, surveyor, or attorney where necessary.

A proper understanding of the median line can prevent disputes, ensure fair allocation of maintenance costs, and assist trustees in fulfilling their statutory obligations effectively.

If you have any questions regarding this, please reach out to us to assist!