Wind shielding
Wind shielding measures how much surrounding buildings or vegetation reduce wind loads on a site. Used in AS 4055 to determine the site wind class for housing.
Ask Chalkline about this →Wind shielding is a measure of the degree to which surrounding buildings, vegetation, or other structures reduce the wind loads acting on a housing site. Under AS 4055:2021, wind shielding is one of four factors used to determine the site wind classification. A well-shielded site in an established suburb will attract a lower wind class than a similarly located but exposed site with no surrounding structures.
AS 4055:2021 applies shielding classes from T0 (no shielding) to T3 (full shielding), assessed by counting and sizing the structures within a defined radius of the site. More shielding lowers the classification (and reduces structural costs); less shielding raises it.
Also known as: shielding class, shielding factor.
Category: Compliance & approvals.
Why it matters for builders: a new estate on open land or a single dwelling on a rural block with no surrounding buildings will often be classified T0 (no shielding), which can push the wind class up by one or two levels compared to the same site in an established suburb. This directly impacts the cost of roof tie-downs and structural connections. Building on a semi-rural or greenfield site always warrants confirming the shielding classification before finalising the structural specification.
Related
- AS 4055 wind loads for housing, the standard that includes shielding as one of four site factors in the wind classification process
See also
Last updated: 2026-05-08. Verified: 2026-05-08. Quarterly review for currency.