Green roofs and walls for nature

Walls, roofs, fences and other structures in our neighbourhoods can become homes for native plants and animals. Greening these structures also keeps us healthier.

A green roof is one with plants growing on it. The roof is partially or completely covered with a waterproof layer or planter-style boxes, soil (or similar) and plants.

There is a huge variety of green wall or ‘vertical garden’ designs. The main types are where plants grow in planter boxes or in a lightweight type of soil attached to a wall.

Our Green Cover in NSW Technical Guidelines include information about how green roofs, walls and street design can cool our streets and create more liveable and resilient communities. You can access the guidelines from Adapt NSW’s Climate change, green cover and open spaces webpage.

Benefits of green roofs and walls

You can create your own green roof or wall and help Sydney Nature, while reaping the benefits of more greenery and a nicer place to live.

Green roofs

Green roofs can:

• provide a place for native animals and plants to live and feed
• provide recreational space
• grow food
• add an interesting architectural feature
• add value to a property
• block out noise
• help cool the air
• insulate a building and help save on energy bills
• capture and filter rain and stormwater and reduce local flooding
• make solar panels more efficient.

Green walls

Green walls, also known as vertical gardens or living walls, can:

• help insulate your house 
• block out noise
• grow food
• add beauty and interest to a home
• provide a restful place to sit
• attract butterflies and bees.

The Royal Institute of Chartered Surveyors has developed a guidance note about what to consider when you install a green roof or wall on existing or new commercial or residential buildings.

Construct a green roof

To add a garden to your roof or build a structure with a green roof on it you’ll first need to decide what type of green roof you want. This will depend on the capacity of your roof, how you want to use and maintain it.

Green roofs can support low growing plants, shrubs and small trees.

• ‘Extensive’ roof gardens are light-weight, basic, and low-cost. They usually require little maintenance after a couple of years and often have the ability to be retrofitted to existing buildings.
• ‘Intensive’ roof gardens are heavier and may require structural design and engineering to support the deeper soil needed for this type of garden.
• A ‘semi-extensive’ roof, or a combination of extensive and intensive on the one roof garden, can work when access is limited or when it’s not possible to develop a roof’s structure to support something more intensive.

Once you’ve decided on the type of green roof you want you’ll need to:

• check your structure is able to support a green roof – it needs to be able to bear the weight of the garden including soil when it is wet
• consult a green roof professional, such as a landscape architect and/or structural engineer
• check with your local council about whether you need to put in a development application.

Once the roof is ready, you can plant a mix of plants, including natives, to attract a variety of insects and birds.

Find out how a green roof bonded a group of St Kilda residents in Melbourne and helped local nature.

Types of green roof

An extensive green roof has a growing medium depth of around 150 millimetres and is usually non-accessible or has limited access.

An intensive green roof has a growing medium of typically more than 150 millimetres deep, is heavier and requires a stronger roof structure than an extensive green roof. Intensive green roofs can sustain larger plants like shrubs and trees, along with recreational areas.

Learn more about how to create your own green roof or wall in the Australian Government’s guide to environmentally sustainable homes.

Examples of green roofs

Construct a green wall

You can build a simple, low-cost green wall using a trellis or plant mesh for climbing plants, or you can make something more elaborate.

You can consult a green wall professional consultant, such as a landscape architect, to help you with your green wall project.

You can create a modular green wall that has sections or pockets of light-weight growing medium, like perlite or vermiculite, instead of soil for plants to grow in. Or you can install a soil-less green wall where plants grow on the surface of built structures – these walls are also called vertical gardens, living walls, green facades, bio walls or vertical vegetation.

Modular green walls are more cost-effective than soil-less green walls.

The first thing to think about is where to create your green wall and how you will water and maintain it. An ideal position is a well-lit or north-facing wall or structure.

You'll need to:

• make sure your wall is strong enough to bear the weight of the plants, soil and water system if you are installing one
• work out how you’ll water your plants - will you need to install gravity drip irrigation, pipe networks or an in-built watering system?
• choose plants with shallow root systems that will suit the light conditions of your wall
• check whether you need to apply a waterproof paint on the wall first
• grow a mix of plants to increase your biodiversity.

Examples of green walls

Developed at Macquarie University, Habitat Stepping Stones is a project that helps you find beautiful food, water and shelter elements to add to your backyard, balcony, school or community centre to create a habitat stepping stone for local wildlife.

If you pledge online to add 3 or more habitat options to your place, Habitat Stepping Stones will send you a plaque for your front fence. It’s easy to support your local wildlife.

Find out more at Habitat Stepping Stones.