A sustainability calculator is built into gCADPlus. It provides a mechanism for applying a structured approach to assessing landscape designs’ sustainability and runs in its own window, ‘floating’ on top of the gCADPlus design.
As it runs, the tool poses several questions. Each asks for your assessment of how well a particular ‘sustainable‘ characteristic has been dealt with in the underlying gCADPlus design. Your response to each question is rated with a score ranging between 1 and 10. As a question is answered, a tick appears in a checkbox, the calculator adds the total and calculates a sustainability index. The figure below shows the calculator in action.
The figure below shows the first question. Here you are asked to assess the proportion of the landscape area that is open to the penetration of rainfall, i.e. it wants an estimate of the percentage of permeable surfaces in the design. A site with a high proportion of permeable surfaces will score highly on a scale of 1-10.
The second question is shown below. Here you are asked about the species chosen and their reliance on extra watering. If all species chosen in the planting plan will survive on natural rainfall after the first year, score highly.
More questions follow.
The calculator keeps a running total and presents an overall score at the end of the series of questions. We suggest that if a design scores> 50%, this means that reasonable attention has been paid to ensuring a sustainable landscape design.
Our users report that this tool helps focus on issues of sustainability that are easy to overlook while they may be concentrating on other design issues.
Tip: If the question does not apply to the assessed design, leave it unchecked.
Sustainability – some thoughts from Ross Uebergang – www.rossu.com.au
Sustainability in the landscape is a must. We live in a world of finite resources.
- Reflect: If I want a deck, do you need one this size? How often will I have 80 people on my deck? Could I go without, or could I use a substitute?
- Reduce: Can I set my areas up to use less energy?
- Refuse: If the idea is lousy, say no. You may not need it, or there may be a suitable substitute.
- Reuse: Is this material at the end of its usable life in the rebuild? Can I find another use for it? Can I find someone else who can use it?
- Recycle: Can this material be processed to have a new life? This is the next alternative to reusing. Can I use a recycled product instead?
Tips for gardeners
Mulch and Compost – Go to a local landscape supplies centre and use their courtesy trailer or get it delivered. The mulch will mean less watering, better soil structure, and healthier plants while limiting the number of weeds in your garden and spreading throughout your neighbourhood. Depending on the style of mulch you choose, you could spend as little as $30 per 10 m2 if you use your local council mulch or around $60 for decorative mulches. Compost will create healthy soil that needs many fewer additives.
Choose sustainable materials—If you must install hard surfaces like decking, paving, pergolas, etc., choose materials that have low embodied energies. This is the energy needed to extract, manufacture, transport, and install your product. Not only should the materials you use in the landscape be low in embodied energy, but they should also have reasonable longevity. Local toppings are a fantastic choice for low—to medium-use paths.
Limit the use of hardscapes. How often will you have 80 people in your backyard to fill a massive deck? Consider if the space could be filled with plants instead.
Line your fences with fruit trees. Fruit trees are kept producing with low maintenance. If you don’t have the time to put in vegetables every 12 weeks and maintain a vegetable garden, perhaps fruit trees are for you. They require limited maintenance; you do not have to replant every season. Each year, more dwarf varieties come out that take up less space, which is fantastic for the small garden. Generally, in the Australian garden, fruit trees require sun for most of the day to provide fruit that is plentiful and tastes good. A fence line is a great spot to find the sun.
Can I fix it? Your deck might be looking a little ragged at the moment, but perhaps all it needs is a smarter choice of decking boards. Perhaps it just needs a fresh coat of oil. Maybe a coat of paint on the back fence will revitalise the plantings in front of it.
We love the philosophy adopted by one of our gCADPlus users. Visit sparethoughts landscape design.