Permaculture Design Process – 4. Identifying functions

By Aranya


This is the stage where we identify what will be the focus of the design. We take what we have learned from the client interview(s) & determine what key functions are required (there may be many, but some will be more a priority than others).

When we visit somewhere new, we often start redesigning that space in our heads, based upon things we have seen in other places, things that we would prefer if it were ours. This redesign usually takes the form of the imaginary placement of objects, be they plants, animals, tools etc. While aspects of this initial assessment may turn out to be good, each new space has its own unique set of circumstances & is best approached as such. Bill Mollison has a saying; ‘Vujà dé’ – the feeling that you have never been in this situation before – & that is the best way to approach each new design.

The process

So we’ll work backwards from our initial ideas & identify why we thought those objects were a good choice. What actually were we aiming to achieve through their inclusion? Was it a need for a degree of food or energy self-sufficiency? Or protection from strong winds? Did we want to attract wildlife? Or just have a beautiful place to relax in? These questions define our design.

For instance if we thought an apple tree would be appropriate, why were we choosing it? Was it because it would feed us? Or stabilise the soil? Or provide an income? Or just look beautiful when it flowers in the spring? Stepping back to identify the functions we want is an important step in choosing the very best systems or elements to perform them.

Confused about the difference between functions, systems & elements? Maybe this will help: Elements are individual things that make up a system when put together. Either elements on their own, or complete systems, perform (one or more) functions. A function is what you want to achieve & the system or element is the means by which you achieve it. Here are some examples:

Function System Elements
Wind protection Hedge Hazel, Elder, Ash, Bramble, etc.
Fence Posts, wire, wooden slats, etc.
Irrigation Rainwater harvesting Gutter, downpipe, butt of tank, pond
Keyline system Dams, sluices, gulleys, trees, etc.
Soil improvement Slope stabilisation Terracing, swales, gabions, trees
Nutrient cycling Composting, green manures, treebog
Mulching Cardboard, bark, compost, straw
Food production Veg garden (plants) Carrots, potatoes, onions, etc.
Veg garden (structure) Raised beds, composting system, tools
Orchard Apples, Plums, Pears, etc.

Note that while Hazel has appeared here as an element in a hedge system to provide wind protection, it could also have been listed as an element fulfilling the functions of soil improvement or food production.

Identifying the key functions

Looking through your notes from the client interview(s), you should be able to identify what their key needs are, along with less important things that your client(s) would like to have too. Of course, your challenge as a designer is to give them everything!

In addition you will have hopefully identified (from both your site survey & client interviews), what the current key limiting factors are. They may be associated with resource leaks, such as soil erosion, water run-off, badly insulated buildings, high maintenance costs, wasted volunteer help etc. Plugging these leaks (soil stabilisation, water harvesting etc.) will also be important functions, as they will produce the greatest change for the least effort.

So what are the key functions in this design?

  • The most important things that your clients want from this?
  • Those needed to remedy the worst energy leaks?

For the purposes of our design practice it is best to select just the three or four most important functions to carry forward to the next stage.

Here are some functions that may be relevant to your design:

Accommodation, shelter, privacy, warmth, leisure, children’s play area, food production, soil conservation, soil improvement, energy production, windbreak, water supply, irrigation, drainage, waste water treatment, fuel supply, wildlife habitat, fodder, education, access, community integration, cash income etc.

And onto the analysis stage…

OK, well done! Once you have determined these key functions, we can move on to consider how best to fulfil them (part 5).


Go to part 5 – Choosing elements & systems