None of that suits a modern high strength cement mix. Put a hard render over soft old brick and the render wins, which means the brick behind it starts breaking down instead. We mix to suit what is actually behind the wall, and on heritage jobs that usually means going softer and more breathable, not harder.
Rising damp is the Inner West problem
Most terraces around Newtown, Enmore and Petersham were built without a damp proof course, or with a slate one that failed decades ago. Moisture wicks up from the ground through the brick, carries salt with it, and pushes the render off the wall from behind. You see it as bubbling and flaking in a band along the bottom metre of the wall.
Rendering straight over it hides the problem for about a year. We would rather tell you that up front, sort the drainage and the damp course first, then render. It costs more on day one and it is the only version that lasts.
Heritage conservation areas and what you can actually do
Large parts of the Inner West sit inside heritage conservation areas under the Inner West Council LEP. That does not mean you can never render, but it does mean that rendering over a face brick or sandstone street frontage can need approval, and in some streets it will be knocked back.
Rear elevations, side walls, courtyards, garden walls and interiors are usually far more straightforward. We have worked through enough of these to give you a realistic read before you spend money on an application.