Summer Issue 2021 - 86

solution file
segments (namely 2, 3, 4, 5, 6, 10,
12, 15, 20, 30, and so on), which are
particularly useful in planning, development,
and construction.
Metric-acre urban blocks could
ease divisibility as well as increase
land use efficiency for both residential
and commercial uses. For
residential subdivision into lots,
60-meter lengths easily subdivide
into multiple, identical, and usable
5-, 6-, 10-, 15-, 20-, or 30-meter increments
(16, 20, 33, 49, 66, or 98 ft).
Conventional block subdivision into
eight single-family detached (SFD)
lots of 15 by 30 meters (49.2 by 98.4
ft equals 4,841 vs. 5,000 sq ft) yields
only a 3 percent difference.
When compared with a full
Metric-acre urban blocks could ease divisibility as well as increase land use
efficiency for both residential and commercial uses. For residential subdivision
into lots, 60-meter lengths easily subdivide into multiple, identical, and usable
5-, 6-, 10-, 15-, 20-, or 30-meter increments (16, 20, 33, 49, 66, or 98 ft).
the allocation of land for the raising
of crops. Now the urban acre is
used mostly to raise buildings. We
do not build in narrow, 660-footlong
strips. We build in compact
blocks. Since the metric system is
nearly universal, the United States
should facilitate its adoption in a
way that is still compatible with
building practices under customary
imperial measurements, but which
is completely accurate in meters.
Therefore, a square metric acre
could be better defined as 60 by 60
meters (196.9 by 196.9 ft), which
is close to the historic American
200-by-200-foot (60.96-by-60.96-m)
urban block. But it fits squarely and
accurately into the metric system.
A 60-by-60 metric acre is precisely
3,600 square meters, 36 percent of
a hectare. That metric acre is also
analogous to-and fits within-the
Jeffersonian U.S. national survey of
six-square-mile townships divided
into 36 one-square-mile (640-acre)
sections. Similarly, the metric acre
contains 36 square dekameters
86
URBAN LAND
(dkm2, 10 by 10 m equals 100 sq m,
which equals 1,076 sq ft).
Divisible Efficiency
Lacking a convenient metric analog
to the size of an acre, the metric
system also lacks an analog to the
foot. However, since 30 centimeters
(300 mm) equal 98.4 percent of
a foot, one could mediate that to
a metric foot, like the metric acre,
metric mile, and metric ton. And
one could harmonize the 10-based
metric system by dividing a 300-millimeter
metric foot into 10 metric
inches of 30 millimeters. (A direct
conversion of 12 inches is 304.8
millimeters.) Smaller dimensions
are often quoted in millimeters to
prevent confusion and to reduce
sizing to two measures-meters and
millimeters. However, the metric foot
aids conceptualization without diversion
from metric accuracy.
The concept of choosing base divisions
of 60 meters as metric analogs
is also based on the large number
of divisors for equal whole-number
SUMMER 20 21
customary acre, however, a
3,600-square-meter metric acre,
versus its 4,047-square-meter direct
conversion, would equate to an 11
percent reduction, or 4,810 square
feet, as large as another lot, increasing
land use efficiency. Planners and
developers could realize increases in
both density and productivity.
It is important to note that the
size reduction does not come at
the expense of productivity or
spaciousness. A 60-meter block
frontage could easily be divided
into six 10-meter-wide (33 ft) townhouse
lots, yielding 12 to the metric
acre. A developer could build fivemeter-wide
townhouses, which-at
16.4 feet wide-yield larger rooms
and are wider than typical 15-footwide
Savannah townhouses. The
lots could be 15 by 30 meters (49
by 98 ft), with a six-meter (20 ft)
cross-easement alley between rows
of them, yielding 24 to the metric
acre (27 per imperial acre).
For commercial uses, envision a
sustainable 12-story, mass timber
structure on a quarter of a metric-acre
(30-by-30-m) lot. It could
house a universal-use building
tower for multifamily, hotel, or
office functions. The post-andbeam
tower divided into nine
one-dekameter segments would
yield eight apartments or condominiums
per floor, half of which
are corner units, around a central
core, times 12 stories, producing
96 units. If a second tower were
built checkerboard fashion on the
opposite quarter-block corner, the
yield would double to 192 units per
metric acre even if the two remaining
quarter blocks were developed
as 900-square-meter (9,688 sq
ft) parks. And no unit's windows
would face another's.
The same building could be
erected as an all-suite hotel with
10-by-10- and 5-by-10-meter units
(33 by 33 and 16.4 by 32.8 ft) at 12
units per floor yielding 144 rooms,
all wider than typical hotel units.
Again, that could be doubled on
the opposite corner, raising density
to 288 units per metric acre.
Developed as an office building,
the same structure would yield 12
full-floor, 900-square-meter (9,688
sq ft) leases, whose 10-by-10-meter
(32.8 ft) bays would be interrupted
by only four internal columns and
would be surrounded by four glass
walls with uninterrupted views.
Offices of that tenant size and configuration
could capture a sweet
spot in the market and drive premium
rents.
Metric Block Patterns
The 60-by-60-meter (196.9-by-196.9-ft)
metric acre is the ideal size to be
the net usable core block within an
80-by-80-meter (262.5-by-262.5foot,
6,400 sq m) gross metric
block, which provides a 20-meter
right-of-way (65.6 ft) surrounding
ring for streets, parking, street trees,
and sidewalks. That gross metric
block mediation is only 1 percent
less than the 80.45-by-80.45-meter
(264-by-264-ft, 6,475 sq m) size of
the Vancouver/Portland blocks plus
rights-of-way.
Some developers have criticized
the net-to-gross efficiency of such
smaller blocks. But those critics
often ignore the fact that such
smaller blocks can yield twice as
many on-street parking spaces as
MACHT & COMPANY
Summer Issue 2021

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