HomeMy WebLinkAboutCSD - Ithaca NY Randall Arendt Rural by Design 10.01.2026•AICP recognizes that the New York Upstate (NYU)
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Using Conservation Clustering to
Incorporate significant open space
into new subdivisions
Built at Various Densities
Copyright 2026 Randall Arendt
This is a Density-Neutral Approach
that respects property rights
and is fair to landowners
and developers alike,
and
which also costs less to create than
conventional “cookie-cutter”
subdivisions with higher
development costs.•
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Density Bonuses/Incentives
are NOT Needed to “encourage”
this approach in NYS
because state law allows communities to
require it.
However, bonuses could be useful to
encourage higher percentages of open space,
or to provide public access.
Conservation Clustering offers the same flexibility
in lot size and dimensions as does
Fixed Area Ratio Zoning and
Density-Averaging Zoning.
But it is a more complete planning approach
because its central organizing principle
and main design goal is to
maximize the amount of unconstrained land –
not wet, floodprone or steep –
for preservation, in addition to unbuildable areas.
And to create permanent interconnected open
space networks.
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Conventional Zoning
versus
Much Better Alternatives
Mapping:
1) Build-out Scenarios
and
2) Potential Greenspace
Networks
Choosing which Site Features
to protect,
and
which to build on
Acres Saved with Conservation Subdivision Design
Towns and Townships
Westborough, MA 448 acres
Westford, MA 650 acres
Hamburg Twp, MI 750 acres
Hopkinton, MA 875acres
Counties
Cherokee County, GA 1,374 acres
Waukesha County, WI 1,670 acres
Hanover County, VA 5,550 acres
Calvert County, MD 7,765 acres
San Luis Obispo County, CA 9,000 acres
Nationwide Estimate: 100,000 to 180,000 acres
Benefits of Conservation Design
(Economic, Environmental, and Social)
To the Town
(better implements key Comp. Plan policies, shorter street
lengths to maintain in perpetuity)
To Subdivision Residents
(views, trails, social interaction)
To Developers
(lower grading and infrastructure costs,
faster sales, premium lot pricing)
Ways that Conservation Lands
Have Been Used
The central thesis of
Last Child in the Woods
is that today’s children are increasingly
separated from the natural world – a
condition described as a
“Nature-Deficit Disorder.”
The author argues that this deficit harms
their physical, mental, and emotional
health.
As a subdivision site designer,
I have always striven
to think like a nine-year old
who cannot drive to natural areas to
enjoy them, and who must get about
only on foot or on a bicycle.
I recommend that all planners
(and PB members) think the same.
Site Visits:
An Essential First Step
with Applicants (and abutters)
To Gather Information on
Special Site Features
Site Visits should, whenever possible, be
immediately followed by a Planning Board Workshop
Meeting held in a handicap-accessible room,
where design ideas can be suggested and discussed to
improve the initial Sketch Plan layout, while field
observations are still very fresh in everyone’s mind.
Both the Site Visit and the Workshop Meeting should
be publicly advertised for maximum input and
participation.
Designing Around
Natural & Cultural Features:
The First Design Step
•ss
Designing to Protect
Rural Roadside Vistas
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Codes should require neighborhood greens
to provide visual and social community focal
points and to provide opportunities for
casual meetings and conversations,
plus places for informal games (such as
playing catch, tossing frisbees, flying kites).
A good size range is 5,000 – 20,000 SF
Four-Step Design Process
Identify Potential Conservation Areas
Locate House Sites
Connect Homes with Streets
Draw in the Lot -Lines
Compare Two Sketch Plans
(prepared by a LA or Planner)
BEFORE
“Preliminary” Plan is Submitted
Eden NY Town-wide Maps
of
Primary and Secondary
Conservation Areas
Secondary Conservation Areas
can include individual trees or tree groups
to become focal points
in new neighborhood greens.
Hands-on Design Exercise
Permanent Protection
of the Open Space
Through Conservation Easements
held by
Land Trusts
Counties or Municipalities
State or Federal Agencies
Ownership of the Open Space
Homeowner Associations
Land Trusts
Counties or Municipalities
Management
of the Protected Open Space
Performed by the Open Space Owner
According to a Management Plan
Approved by the County or Municipality
Detailing what needs to be done,
how frequently, and by whom
Conservation Subdivision
Examples
with
Individual Wells and Septics
in Rural Areas•c
Fields at Cold Harbor
Hanover County, VA
25 one-acre lots on 120 acres
(nearly 80% open space)
Individual on-lot Wells
and
Individual on-lot Septic Systems
Conservation Subdivision
Examples
with
Individual On-Lot Wells
and
and Shared Septics
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Indian Walk
Buckingham Twp., Bucks County, PA
11 homes on 50 acres,
Including the original farmhouse and barn.
Cluster lots range from 20,000 to 30,000 SF
Nearly 40 acres (90%) of preserved land
Individual Wells and Shared Septic
Conservation Subdivision
Examples
with
Shared Wells and Shared Septics
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Canterbury
Buckingham Twp, Bucks County, PA
Starter Homes in a Conservation Design
16 Quarter-acre lots on 17 acres
(about 75% open space)
Shared Wells
and
Community Septic System
Conservation Subdivision
Examples
on Public Water
– with On-Lot Septic
-- with Off-Lot Individual Septic•c
Public Water
and
On-Lot Septic Systems
Jarvis Farm
Westford, MA
13 half-acre lots on 20 acres,
with 60% conserved
Public Water
and
On-Lot Septic Systems
Public Water
and
Off-Lot Individual Septic
(in the protected open space)
With public water, one-acre houselots
can be reduced to ½-acre in size
with individual septic systems
located
on the best soils
on the property.
(There are no wells on the property to worry
about impacting.)
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Strathmore Farm
Madison, CT
24 homes on 29 acres
Condominiums on EUAs of 10,000 to 12,000 SF
Public Water, with
Off-lot Individual Septic Fields
in the common open space
Public Water
and
Community Septic
(in the protected open space)
Partridgeberry Place
Ipswich, MA
20 lots @ 8,500 SF on 37 acres
(a density of about two acres per dwelling)
Public Water and Community Septic
Weatherstone
West Vincent Twp.
Chester County, PA
273 homes on 250 net buildable acres
(1.1 du/acre)
195 acres of open space (65%)
Land Treatment (Drip Irrigation)
Multiple Shared
Septic Systems
On utility easements in the open space
with Public Water Supply
Long Hill Farm
Guilford, CT
85 dwellings on 50 acres
55 condominium lots of 5,000 each
35 condo units in large barn-like building
Shared septic in open space, Public Water
BOTH
Community Well
and
Community Septic
The Ponds at Woodward
Kennett Township
Chester County, PA
57 homes on 120 acres (Two-acre Density)
About 70% open space
Community Well
and
Community Septic
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The landowner was offered $800K
for this 100-acre farm in 1989 by a
developer who wanted to build a 230-
unit PD.
But after the Township adopted
Conservation Design, another developer
bought the farm for $1.3 million to build
this 57 home community.
Even though the new plan involved only one-quarter of that density, the developers recognized that its infrastructure costs would be much lower and that its units would command much higher sales prices. As a result, the township’s subsidy offer proved to
Even though the new plan involved only one-quarter of that density, the developers
recognized that its infrastructure costs would be much lower and that its units would
command much higher sales prices. As a result, the township’s subsidy offer proved to
be unnecessary.
be unnecessary.
The second developer looked more closely
at the very high infrastructure costs
involved in the 230-unit PD, and
he found that a much simpler plan with far
lower infrastructure, greater sales appeal to
homebuyers, would generate as much NET
PROFIT – and would sell more quickly.
His plan was built and was highly
successful.
BOTH
Public Sewer
and
Public Water
Stratford Hall
Weddington, NC
35 homes on 35 acres
Lots average 1/3-acre each
Roughly 55% open space
Public Water and Public Sewer
Farmview
Lower Makefield Twp., Bucks County, PA
Half-acre lots within a one-acre density
50% open space
Public Water and Public Sewer
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The Park at Wolf Branch Oaks
Mount Dora, FL
116 lots on 116 acres
Lot sizes from 12,000 to 30,000 SF
50% open space preserved
Public Water and Public Sewer
Summerfield
Elverson Borough, Chester County, PA
318 units on 137 acres
(2.3 dwellings/acre)
Public Water and Public Sewee
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Battle Road Farm
Lincoln, MA
5 du/ac gross (120 dwellings on 24 acres)
40% Affordable (48 units)
60% are 1) Senior and 2) Unrestricted
59 % Permanent Open Space
Layout designed like
“a golf course development without the golf course”
Questions
and
Answers
Final Section –
Improving the Design of
Higher-Density Housing:
Poplar Gardens
an affordable single-family neighborhood
in Boulder Colorado
Built at 10 dwellings per acre
This townhouse density of 10 du/acre
is achievable by designing
Single-family Detached homes
at townhouse widths
(typically 20-24 feet wide)
and the neighborhood setting
is vastly improved
by locating the homes facing a central green.
This design approach is known as
“Pocket Neighborhoods”
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These central greens should be at least 30 feet wide,
provided with a sidewalk border,
and planted with shade trees at 30-foot intervals.
Below is Poplar Gardens, seen from above,
showing 20 years of tree growth.
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An excellent way of ensuring that affordable
units blend with market-rate units is to
require that they often share the same two-,
three-, or four-family building.
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In snowy areas, parking next to homes is
far preferable to remote parking lots.
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The “central green” idea
in “Pocket Neighborhoods”
can also be applied to cul-de-sac streets
designed as a one-way loop.
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The central greenspace can be used for
“rain garden” stormwater
by pitching the pavement inward.
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Example of a “looping lane” (or “close”)
with rain garden basins.
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“Detached Townhouses” can also be built
without central greens,
but MUST have rear-access garages.
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Example of a well-planted rear-access lane.
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Detached Townhouses are not a new idea.
The three Victorian examples below
require only 100 feet of street frontage.
Failing to learn from better historic examples,
these front-facing garage doors on narrow homes
seriously dominate the streetscape.
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Alternative example of narrow, affordable
single-family “detached townhouses”
with rear garages, in Davidson, NC
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Rear driveway access makes great sense for
very efficient narrow lots.
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Without rear access, front-facing garages
totally dominate these narrow affordable
homes and diminish the streetscape.
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Solution: Without rear lanes to access garages,
require front-facing garages to be recessed at
least 10 feet behind the main house facade.
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Another design alternative is side-entry garages.
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Garage orientation is a important design issue
because many developers maximize efficiency by
narrowing lot widths, and locating garages in front of their
houses -- instead of to their sides.
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Attaching garages to house fronts (instead of to their sides)
becomes much less of a visual problem when
the garage doors face sideways - and not toward the street.
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Two- and Three-family designs
could fit very well into your town…
or not -- but adopting design guidelines
or standards could certainly help.
Towns could influence duplex designs,
-- or they could just take their chances.
The basic choice is whether to work with
applicants to achieve better duplex design
-- or to simply let things happen.
This classic two-family design contains
one 2-BR unit with 1,164 sf, plus
one 3BR unit with 1,356 sf.
The duplex in the previous slide contains 2,520 sf,
measures 42’ x 30’, and fits well on a 64-ft wide lot
-- meaning only 32 ft of street frontage per dwelling.
The floor plans are shown below.
This built example shows the two main entrances, one for
each unit, the first on the front and the other to the side.
This clever doorway arrangement disguises the fact that
this building contains two dwellings.
Affordable Duplexes
(from Barrington, RI)
Meeting official requirements
for income and rents. State-approved.
Officially Affordable Duplexes
(from Barrington and East Greenwich, RI)
According to the architect of these examples (Don Powers),
the main key to excellent design (which is only marginally
more costly) is to substantially lower each unit’s land cost
by increasing density slightly more than normally required
for building very plain “boxy” affordable designs.
These house designs from Don Powers’
Cottages on Greene project
show that
attractive appearances can be achieved
without much extra trim or cost.
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More officially-affordable Duplexes
in a simple vernacular style
(from Davidson NC)
Duplexes with and Without Garages
(The example on the right
could have garages to the side or rear.)
Three-family design regulations
could also be adopted by your town.
Below is a classic Victorian design, a pair of which
was built facing each other at a street intersection…
(Built by the Davidson NC Housing Coalition -- DHC)
TheThe DHCThe design for the previous three-family
example was based on this largish Victorian
home located several blocks away in Davidson.
Two more Three-family designs
(from Eagle, CO)
Accessory dwellings can be
added onto existing homes (left)
or built as part of new construction (right) --
and can be in either rural or in-town settings.
Three-family affordable dwelling (left)
in a single-family detached neighborhood
at Cottages on Greene (East Greenwich, RI)
Building Scale and MassingThe scale and massing of large buildings
can be reduced
with Right-Angle Wings and
Different Roof Ridgeline Heights –
which should be spelled out in local regulations.
Design Guidelines sketch showing
massing reduction with wings and
varying roofline heights and directions
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Four-Family buildings can be based on the
New England “connected farmhouse” tradition.
(“Big house, Little house, Backhouse, Barn”)
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“Good design and good detailing
do not, on their own, increase cost much at all.”
-- Dave Malushizky, architect and member of Davidson’s
Design Review Board, speaking about the below
four-family affordable (Creekside), containing 3,749 sf
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Dave went on to say that keeping designs simple
and using only as much detailing as needed
is very important.
And it’s also necessary to design the homes so
they blend in very well with their neighbors.
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Four-Family Dwelling Design (left)
Based on “Connected Farmhouse” Tradition
This late 19th c. neighborhood in Brunswick Maine
accommodates 20-25 persons/acre
with many narrow/deep houses,
plus carriagehouses converted to dwellings.
Below is one of the multi-unit homes on Brunswick’s
School Street that helps this end of the neighborhood achieve
an affordable density of 10 dwellings per acre –
equivalent to “Detached Townhouse” density.
Zoning regulations should always contain provisions
for converting
large older homes into smaller living units,
including a healthy mix of
affordables and market-rate dwellings.
Regulate building size directly
(by floorspace area)
and not indirectly (by “unit count”)
For example:
Max. 2,500 sf for standard designs
and, say, up to 4.500 sf
to encourage better designs
with right-angle wings, roofline variation,
façade setbacks, etc.
To avoid “too-large” buildings that are
out of scale with their surroundingsA
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Because units can vary greatly in size,
regulating building size by unit count
doesn’t make a lot of sense.
For example, six units for one- or two-person
households at 750 sf = 4,500 sf.
But six units at 1,200 sf = 7,200 sf,
which could simply be too large
for many communities,
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Six-unit Buildings
often contain about 7,000 sf
and are out of scale in many towns.
But with an upper limit of say 4,500 sf plus design
regulations, new affordable housing
could blend in much better.
Increase permitted units per acre to whatever extent
is needed to make them affordable,
and then add a few more units/acre
to offset the marginally higher costs of making them
more attractive, including building a somewhat
larger number of smaller buildings
that would be more in scale with their surroundings.
Architect Donald Powers, designer of some of the most
attractive affordable housing examples in this presentation,
recommends small supplemental density bonuses
to cover the small additional costs
involved in attaining better-looking homes.
•
He’s also told me that it’s very difficult
to codify design regulations and feels the most
important elements deal with the proportions of
buildings and their windows and roof shapes.
He also added that simple little “workers’ cottages”
without much special architectural trim can
be very attractive when arranged
around a small central green or “close”,
or when their “presentation to the street”
is designed to fit comfortably
with neighboring homes.
These simple facades at Powers’ Cottages on Greene
exemplify the quality design that can be achieved by
paying attention to proportions and roof shapes, and
without any elaborate architectural trim.
These two fairly basic cottages are neighbors to
the Cottages on Greene infill.
The cottages on the Greene Street end were given
slightly fancier porch treatments to create the best
public face to the project.
Ditto for the treatment of the two end buildings at
the Poplar Gardens cottage cluster.
ditto for the end buildings at Poplat Gardens.
… whereas the interior cottages are plainer.
ditto for the end buildings at Poplat Gardens.
Don Powers’ concluding comments to me were that
the best way for towns to increase their affordable
housing stock is to be proactive and take the initiative,
as Lincoln did at Battle Road Farm.
Of course, this is easiest when the town owns suitable
land in suitable locations. But it could buy rural land
zoned for two du/ac, upzone it for affordable housing,
and recoup its costs by selling it to developers wanting
to build at much higher densities.
In doing so, the town would have
far greater control of the site plan and
the building designs, as did Lincoln.
Thank you.
Randall Arendt
rgarendt@comcast.net
www.greenerprospects.com
Copyright Randall Arendt 2026
But may be presented for educational purposes
by Tompkins County towns
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