Wind Post Requirements for Walls Adjacent to Neighbouring Properties

Whether a wall alongside a neighbour’s property needs a wind post is a common point of confusion. The key question is: does the wall have an external face exposed to wind?

True Party Walls: No Wind Post Required

A true structural party wall shared between two dwellings has no exposed external face. It is enclosed on both sides — your interior on one side, your neighbour’s interior on the other. No external wind pressure acts on the wall at all. In this case, no wind post is required.

Walls Adjacent to a Neighbour’s Extension

Where your wall runs alongside your neighbour’s extension but is not structurally shared with it — for example, your original external wall is now abutting but not bonded into their separately built rear extension — the situation differs.

If there is a gap between the two structures (even a small one, e.g. at expansion joints or construction tolerances), wind can still reach the external face of your wall. If the gap is negligible and the walls are effectively abutting in close contact, the wind exposure may be small — but it is not zero unless the walls are structurally bonded.

The answer depends on the wall’s slenderness and the degree of lateral support it receives from perpendicular walls. A short wall well-supported by returns on both ends is unlikely to need a wind post. A long, tall, slender wall with openings may require one.

When a Wind Post Is Likely Needed

Even with a neighbour’s property alongside, a wind post may be required if:

– The wall panel is long and unbraced — no perpendicular walls or piers along its length
– Two full-height openings exist side by side with only a narrow masonry pier between them — the pier is too slender to be treated as a buttress
– The wall is tall relative to its thickness beyond the slenderness limits of Part A

When a Wind Post Is Unlikely Needed

A wind post is generally not required for walls alongside neighbouring properties where:

– The wall is short (say, under 4–5 m)
– It has substantial masonry returns or piers providing lateral support
– There are no large openings that isolate slender sections

Confirming the Requirement

If you are unsure whether your wall needs a wind post, raise a Change Request with PorthouseDean. We will check the wall geometry against the slenderness limits and loading conditions and give you a definitive answer.

Contact us or raise a Change Request to confirm whether a wind post is needed for your project.