There are several things to consider when designing a green façade for a building, more so if the building is a heritage structure. In addition to heritage conservation laws that restrict changes on these buildings, one will need to factor in key considerations such as availability of building plans, condition of the structure, load bearing capacity, planning permits, safety and even the climate.

Designing a green façade for a heritage building can be a much more complex job than usual. It is highly likely that the building’s drawings are inaccurate or outdated, and may not currently match the actual building on site. A site inspection prior to start of work will reveal the true condition of the building. For instance, older buildings may have walls that are several layers thick, or a brick building could have crumbling mortar.

Key considerations for green facades on heritage buildings:

Load bearing capacity

Though a green façade is lighter than a green wall, it’s important to recognise that old bricks and sandstone, typically found on heritage buildings, may not be able to take a lot of weight. First determine the dead load of the green facade – this is calculated based on the weight of the frame and components as well as that of the plants.

Older buildings are also not designed to have frames and cables pulling on them. The design of the green facade will need to be modified to suit the building.

Planning permits and local laws

Before planning a green façade, it’s important to check with the local council regarding permits and laws governing building modifications. A heritage building site could be affected by a heritage planning overlay, which may apply to design and development, and/ or to neighbourhood character if the building is in a heritage conservation area.

A heritage listed building has historical significance, and any changes may require approval from the local heritage authority.

Access, safety and climate considerations

A green façade installation should also factor in aspects such as vehicular access and pedestrian safety, and also ensure the vegetation does not intrude into a public area.

Local climate conditions will play a role in the design of the green facade, especially its ability to withstand extreme conditions and even in the choice of plants.

Consult with Tensile if you are considering installing a green façade on a heritage building.