Exterior Trim near you

Three different instruments can catch external trim, and they are worth telling apart. A state heritage listing is the strongest and rarest. A local heritage listing sits with the council: in Brisbane, changes to a local heritage place require a development application unless exempt under a heritage exemption certificate or a general exemption certificate. A character or traditional building character overlay is the broadest and catches ordinary houses that nobody thinks of as heritage.

Inside a character overlay the test is about appearance and streetscape rather than performance. Brisbane's overlay applies to some areas and streets of older suburbs that have a distinct identity based on building character, materials, layouts and setbacks. Demolition of features such as windows, doors, balustrades, window hoods and fretwork forming part of a building constructed in or before 1946 is dealt with under the overlay codes, and some minor demolition in the overlay does not need planning approval, including removing a post-1946 alteration to reveal the original design, or reconstruction with the original form and materials.

The practical rule is therefore simple. Like-for-like repair or reinstatement of an original detail is usually the safe path, and substitution is where the risk sits. Before you replace a profiled timber detail with a plain modern one, or a timber balustrade with metal, ask the council whether the overlay applies to your address and what it expects. A written answer costs nothing and settles it.

Record before you remove. Photograph the detail in place, measure the profile, and note how it returns at corners and terminations. On a character house this is the difference between reinstatement and approximation, and it is the only record that will exist once the old moulding is in the skip.

Then look at what is behind it. Trim at a window or door head, at a corner, or at the junction between two materials is almost always covering a flashing, and if the trim has rotted the flashing is the first suspect. Part 7.5 of the Housing Provisions requires openings in external wall cladding exposed to the weather to be flashed with materials complying with AS/NZS 2904, with the flashing extending beyond the reveals and lapping in the direction of flow. Replacing the moulding without correcting the flashing means doing it again.

Then the new work: material chosen for the exposure and the termite risk, end grain and cut ends sealed before fixing, fixings appropriate to the environment, and the profile matched where a character or heritage control applies. Prime and paint all faces including the back before fixing where the manufacturer allows, because the face that never gets painted is the one that fails.

External trim is general building work almost everywhere, and the notable thing about it is how often a trim job sits below the value thresholds that trigger licensing and a written contract at all. A run of architraves or a few metres of barge board is small money. That is convenient, and it is also why trim is where unlicensed operators concentrate, and why the protections that come with a written contract are missing on precisely the jobs that alter the face of a character house.

Where the trim is part of a roof or eaves assembly the licensing can shift. Queensland's roof and wall cladding class covers designing, fabricating and installing external flashings, metal ceilings and associated soffits and fascias, and the metal fascias and gutters class covers fabricating and installing external flashings and associated soffits, fascias and gutters. In New South Wales, roof flashings sit inside roof plumbing. So barge capping and fascia trim can be a different licence class from a window architrave on the same house.

Approvals sit separately again and are decided locally. On a house in a character or traditional building character overlay, or on a local or state heritage item, the trim question may be a planning question before it is a building one. Ask the council which applies to your address before you commit to a design.