Form: The Ecological Pattern with an ecological underlay
design is a hypothetical plan for a real site in Surrey, B.C. The
streets are arranged in a grid configuration that has been modified
to allow for the preservation of existing streams. The larger context
outside the site would include commercial/transit corridors
within a five minute walk of all residents. Within the boundaries
of the case study site there are, on average, 5 metres (16 linear
feet) of paved road surface per dwelling unit.
Density: There are 47.7 dwelling units per hectare
(19.3 dwelling units per acre) in this case study site, with
4,767 dwelling units per square kilometre, or a total population
of 11,918 people per square kilometre (assuming an average of 2.5
people per dwelling unit). After allowing as much as 40% for open
space, ecological infrastructure, and non residential uses throughout
the district, we estimate that this pattern would accommodate 7,557
persons per square kilometre. This density is thirty percent higher
than the Traditional Pattern case study and over three times higher
than that of the Status Quo case study site.
Infrastructure: Of the total site area, 26 percent is paved
road, driveway, garages, parking pad, or sidewalk. This produces
51 square meters (549 square feet) of pavement per dwelling unit
(either on it or directly adjacent to it).
In some cases private walks extend from the street to the
rear unit through the side yard. There are, on average, 10 square
meters (108 square feet) of paved surface per dwelling unit.
As with the Traditional Pattern, private, paved driveways are uncommon..
Cars are stored off gravel lanes located behind dwelling units.
The storm drain system in the Traditional Pattern with an Ecological
Underlay is entirely natural. Street-side swales feed into
retention swales which frame the community gardens. Excess water
slowly re-enters adjacent natural streams which are preserved to
receive water. This slow filtration process helps to cleanse
the water and prevent flooding. Streamways double as bikeways,
walkways, and natural recreation areas.
The utility infrastructure of the Traditional Pattern with the
Ecological Underlay follows roads and lanes. There is, on
average, 3.8 metres (12.5 linear feet) of utility run per dwelling
unit. Gas lines are buried in the lanes while electric, telephone,
and cable television lines are held aloft on poles also located
in the lane. Sanitary and water mains are buried in the street right-of-way.
The surface storm drain system eliminates the need for a sub-surface
storm drain system.
Residential Road |
15m (50’) ROW, 1.25m (4’) sidewalk, 3.0m (10’)
shoulder including swale, street trees and parking, 6.0m (20’)
paved street, 3.0m (10’) boulevard including swale, street trees
and parking, 1.50m (5’) sidewalk. |
Residential Mew |
11m (36’) ROW, 1.5m (5’) sidewalk, 2.25m (7.25’) shoulder
including swale, street trees and parking, 3.5m (11.5’) paved
street, 2.25m (7.25’) boulevard including swale, street trees
and parking, 1.5m (5’) sidewalk |
Lane |
5m (16.5’) ROW |
Coverage and Permeability: On average, 14 percent
of each individual lot is paved sidewalk with a further 36 percent
covered by house, carriage house, storage, garage structures and/or
paved car pads. Fifty percent of the total site is permeable
surface which includes lawn, planting beds, street shoulders and
unpaved lanes.
Recreation Space: Local recreation space is provided
by nearby schools, neighbourhood parks, and riparian strips associated
with preserved natural streams and swales. These provide a mix
of field and court sport areas as well as natural areas. Assuming
a a10 minute walking radius, there are approximately 18 square meters
(194 square feet) per dwelling unit of recreation space located in
the immediate neighbourhood. On average, it would take 1 minute to
walk to the nearest recreation area (assuming a pace of 1 kilometre
per 5 minutes). Virtually 100% of residents are located
within a 5 minute walk to the closest recreational space.
Commercial and Transportation Nodes: Commercial nodes
in the Traditional Pattern with an Ecological Underlay are linear
in form and typically located along commercial roads. Additional
secondary commercial nodes occur regularly throughout residential
neighbourhoods. Shop fronts are usually built to the sidewalk,
and parking is mainly on-street or underground. Public transit is
typically provided by busses, which have routes along commercial
streets. On average it would take 2.5 minutes to walk to the
nearest commercial and transportation node (assuming a pace of 1
kilometre per 5 minutes). Virtually 100% of residents are
located within a 5 minute walk to the closest commercial and transportation
node.
Multi-Modal Transportation: The preserved streamways
in the district also include ike and walkways; thus, virtually every
part of the community is accessible via this system which, in combination
with the gridiron street system, provides complete intra- and inter-community
access.
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