Nature directs us on best design

Patterns in the sand indicate the direction of prevailing winds.

Holy Wellington, Batman, the winds have wreaked havoc on Whanganui holidaymakers and on our recently groomed local beach.

On theheels of what has been called the windiest October in decades, we've been hit by another blast in late December/early January.

This tumultuousness appears to exhibit what has been observed by climate researchers, such as Jennifer Francis of Rutgers University (US): The hotter the world's climate gets, the more energetic its weather tends to become.

The good news is that eco-design can address this to a certain degree. The bad news is that non-eco-design is likely to fail with greater frequency over time.

One essential part of the eco-design process is looking for patterns in nature.

This can be as simple and predictable as morning and evening sun angles during winter and summer.

For a passive solar building, the aim is to allow winter sunlight to penetrate deep inside the structure while preventing direct summer sunlight from entering. Along with the strategic placement of windows, something as simple as eaves can achieve these aims.

Other patterns in nature are slightly more difficult to observe, but still obvious to those who engage eco-design habits of mind. Part of the permaculture design process is called a sector analysis, which includes identifying the directions of the prevailing winds as well as strong seasonal winds.

There are lots of ways to find out this information: live in a place for a year; do some research on the internet; ask trustworthy locals; look for sub-patterns in nature that reflect wind direction.

In Castlecliff, it is fairly easy to ascertain the direction of prevailing winds. One way is to look at the pattern of trees listing to leeward. On our section, we have a large willow that grows 30 degrees from vertical, leaning away from the northwest as shown in the photo. To quote Paul McCartney (and Wings): "The willow turns its back on inclement weather; if he can do it, we can do it."

Another way is to go to the beach and look at patterns in the sand. The photo shows small ridges that form perpendicular to the wind as well as scour marks that run parallel to the wind and appear to converge at a "vanishing point" in front of Duncan Pavilion.

While part of eco-design is recognising patterns in nature, and part of it is working with nature, another part is protecting human constructions from its destructive power. An easy example of this is the New Zealand Building Code's strict rules on weather-tightness, and earthquake and wind resistance.

Another example is protecting fruit trees and vegetable gardens from coastal winds. We have spent many hundreds of dollars on wind protection on our section. Almost all fruit trees - even those that are marketed as tolerant of sea winds - need a certain level of wind protection to thrive or even survive.

This is clearly evident at one poorly designed community garden in Castlecliff that lacks wind protection, and where roughly half of the fruit trees have died. Planting a tree without adequate site preparation is neither ecologically wise nor thrifty.

It is hoped that the advice in this column will inspire others to engage in eco-design habits of mind that will result in a healthier, happier, more resilient community for us to share. Again, quoting McCartney and Wings, "with a little luck we can make this whole damn thing work out".

Nelson Lebo consults businesses, schools, and home-owners on all aspects of sustainability. Email: theecoschool@gmail.com