Permaculture Design Principle 4
Energy Efficient Planning - Zoning & Sectors
The key to energy efficient planing is relative location
or the careful placement of elements within a system (zoning and sectors).
Elements are placed not in isolation, but in relation to the dynamics
of the total site. Energy efficient planning is achieved when an element
or a practice is designed to interact efficiently with all of the influencing
elements, including local climate, location including special sites such
as flood plain or rocky hillside, access, local factors of market, etc.
To do this, permaculture designers use simple physics and biology, as
well as specific observation skills.
ZONING
Zone planning is achieved by placing elements in a zone
according to how much we use them or how often we need to service them,
starting with the center of activity, the home or a village, and working
out in concentric circles.
ZONE 0... The house, or home center. Here permaculture
principles would be applied in terms of aiming to reduce energy and water
needs, harnessing natural resources such as sunlight, and generally creating
a harmonious, sustainable environment in which to live, work and relax.
ZONE 1... Is the zone nearest to the house, the
location for those elements in the system that require frequent attention,
or that need to be visited often, e.g., salad crops, herb plants, soft
fruit like strawberries or raspberries, greenhouse and cold frames, propagation
area, worm compost bin for kitchen waste, etc. Zone 1 should include design
elements that discourage fire moving in, a home needs to have some fire
break on all sides. This could include a chicken run, a roadway, a pond,
garden space or short-cropped grass.
ZONE 2... This area is used for siting perennial
plants that require less frequent maintenance, such as occasional weed
control (preferably through natural methods such as spot-mulching) or
pruning, including currant bushes and orchards. This would also be a good
place for bee hives, larger scale compost bins, etc.
ZONE 3... Is the area where main crops are grown,
both for domestic use and for trade purposes. After establishment, care
and maintenance required is fairly minimal provided mulches, etc. are
used, e.g., watering or weed control once a week or so.
ZONE 4... Is semi-wild. This zone is mainly used
for forage and collecting wild food as well as timber production. An example
might be coppice managed woodland.
ZONE 5... The wilderness. There is no human intervention
in zone 5 apart from the observation of natural ecosystems and cycles.
Here is where we learn the most important lessons of the first permaculture
principle of working with nature, not against.
Zoning is abstract however, and in practice
zone edges will blur together. Landform and site access may deem that
the least used zone (Zone V) may be next to the most used zone (Zone I)
for example when a steep forested hill is directly behind the house.
For more complex, or community sites more
carefully worked out linkages between centers and roads, pipes, windbreaks,
etc., for servicing are needed or as David Holmgren calls it "network
analysis".
SECTORS...
are a way of considering the external energies that
move through a system such as prevailing wind direction, site orientation
and aspect (north, south, east, west, etc.), winter/summer sun paths,
underlying geological make up (bed rock causing clay or sandy soil types,
etc.), frost pockets and so on; and how we might best take steps to either
utilize or counter such factors.
When planning for efficiency develop the nearest area
first, get it under control, and then expand to the edges. As distance
increases away from the center, factors change for planning. In Zone I
the factor or strategy for planning for the main design is house climate
and domestic sufficiency. One of the ways of planning for house climate
efficiency is landscaping for energy efficiency.
Landscaping for Energy Efficiency
The permaculture designer treats the built environment
and the natural environment as a whole. Houses are designed not only for
optimum solar advantage but are carefully sited away from sensitive areas.
Prime agricultural land and wildlands are protected. Precautions are taken
for the predictable threats of fire, flood, wind, and cold air drainage.
One of the primary objectives in permaculture is for
designers to develop simple biological alternatives to reduce the need
for the expensive and resource consuming demands of high technology. Proper
shading through landscaping alone has reduced cooling costs by up
to 25%.
Here in Reno, we wish to capture
sun's heat in the winter and block the chilling wind. In the summer we
want to funnel cooling breezes and block the hot sun.
|
To accomplish these goals plant low density, low
crowned trees to the east and northeast of your home. These trees
will filter the sun without blocking the light. High crowned, tall
deciduous trees (trees that lose their leaves during the winter)
along the southern face of your home create shade in the summer,
when the sun crosses high overhead, without obstructing the lower
warming sun in the winter. These tall trees also allow breezes to
pass under their canopy in the summer.
Western exposures overheat in the summer because
of the hot late afternoon sun that blasts that side of the home.
In the winter, the glare can be excessive, especially in snow country.
Short coniferous and deciduous trees an shrubs planted along the
western and northwestern faces will alleviate these problems. These
trees will also serve as a windbreak in the winter.
|
Additional Reading: Landscape Design that Saves Energy, A. S. Moffat
and M. Schiler, William Morrow and Company, Inc., 1981.
|
| Shrubs, vines and ground
covers planted around the home will reduce reflection, draw heat away
from buildings and provide summer shade and winter insulation. Strategically
planted hedges can channel summer breezes to outdoor living areas. |
| A final tip to help reduce
energy needs is to shape pavement, rock gardens, and dark surfaces
in the summer with deciduous trees and shrubs. During the winter,
when these plants are leafless, these surfaces can serve as heat sinks. |
Urban and Community Strategies
Planned Suburban Areas
New suburban subdivisions can be planned for food production and
energy self-reliance. These developments could contain the following
features:
- Solar orientation: orient the houses to the sun and incorporate
passive or active solar space and water heating designs.
- Water drainage: all water run-off is led to swales, which provide
a natural drainage system to replenish groundwater supplies. Trees
and shrubs are planted beside swales to take advantage of moist
soils.
- Greenbelts and common areas: community-owned greenbelts where
the group of homeowners have the say over common areas and can
decide on how the area is used, i.e., orchards, mini-parks, bike
paths, etc.
- Shared resources and food production: lands set aside for meeting
houses, playing fields, recycling areas, and also community gardens,
orchards.
|
- Relative Location
- Where stuff in the right place
- Each Element Performs Multiple
Functions - Multitasking
- Multiple Sources for Each
Need - Redundancy planning to reduce failure
- Energy Efficient Planning
- Zoning & sectors
- Using Local Biological Resources
- "Think globally, Act Locally"
- Cycling of Energy - Reconnecting
movement of energy
- Optimum
Sizing & Stacking - Intensive systems under control
- Accelerating Plant Succession
and Evolution- Working with Nature, not against Her
- Polyculture
and Diversity of Species - Resilience and resistance to pest attacks
- Increasing "Edge"
Within a System - Increasing productivity through edge effects and
natural patterns
Back to Developing Sustainable Landscapes Utilizing
Permaculture Design
|
|
|
|