The views expressed on this page are those of the author and are expressed from a “westerners” perspective when developing communities and subdivisions to International Standards and should be used as information only. They statements and ideas are not meant to influence or change the methodology used on a local level.
However, every effort has been made to include some alternative ideas that may be beneficial to the city planner; the designer and developer of Subdivisions.
We offer technologies to improve the disciplines and outcomes by utilizing Altus Positioning Systems and Carlson Civil Suite software in the survey and design processes.
The concepts discussed are traditional with a few exceptions. For instance, the Carlson Civil Suite software package provides extended automation capacity to design the subdivision using configuration files.
It is cost effective to include topography, cut and fill, road design, Lot layout and storm water drainage collectively in the project. By integrating and linking all the disciplines conflicts between lots, road ways and pipe work are eliminated. In most situations the design features are optimized producing a more compact subdivision; maximizing the land use while producing a superior design.
All aspects of the (concept) design can be modified dynamically and provides the capacity to update the design or sections of the whole design automatically whenever a measurement of design feature is modified or changed.
Comparing the options
Comparing Autodesk Civil 3D with Carlson Civil Suite is like comparing “Chalk with Cheese”. While Autodesk Civil 3D provides some Civil design tools, Carlson Civil Suite provides the Survey, Civil, Hydrology and GIS design tools for a Total Solution for every aspect of a design; at a fraction of the price (less than 50%). The export functions allow the Carlson design to be exported perfectly to Civil 3D. As a consequence the drawings can be shared producing *.dwg files compatible with Industry Standard CAD software. With each Carlson Desktop software license, includes IntelliCAD CAD software at no extra CAD required, upgrades to Carlson software are provided for 10% of the initial cost. Unlike AutoCAD which incurs an annual upgrade cost on top of the Civil 3D license. Total Cost of Ownership (TCO) is very low by comparison.
The major challenge for local “traditional” subdivision designs and the International Standards are those of accessibility and drainage.
In the western world the design of subdivisions has become an art form, developing subdivisions as communities rather than rows of dwelling/houses. A subdivision should be designed to cater for the changes we are aware of, over a the next 20-30 years. This protects the land owners investment and caters for both sociological and climate changes.
Affordability of cars and increased disposable income will impact severely on existing subdivisions; a disaster in the waiting. Grid lock in a disaster will cost lives, access for emergency services is all but a non-event. In existing subdivisions, it is near impossible for two cars to pass making accessibility near impossible in an emergency; they are designed for motorcycle traffic. The roadways are too narrow, open drainage channels are too close to the roadway, they are a particular hazard.
These are issues that must be considered as we design new subdivisions for the 21st century.
The use of GNSS survey equipment provides the surveyor with the capacity to collect a mass of accurate 3D data quickly and efficiently. With a live link between the surveyor’s Carlson SurvCE software and the Desktop Designer using Carlson Civil Suite; the two disciplines are now interdependent and dynamic.
A typical survey includes establishing the legal boundary encompassing the proposed subdivision plus natural features and hazards, the survey should include a detailed topographical (natural surface) survey of the properties and roadways on all sides of the proposed area encompassing over one hundred meters in all directions. Including the depth and size of drains, channels and effluent mains (offsite sewerage treatment), existing roadways and accessibility. This provides a seamless integrated approach preventing road and drainage conflicts for future developments.
For the Developer the questions are complex:
- What is the break even point for sizing lots?
- Is the area large enough to cover the cost?
- Where will the storm water go?
- What if there is a major storm in 1 year, 5 years or 10 years?
- Should we provide an area for children to play?
- Where is the best location for Security?
- Are there safe vehicle routes in an emergency?
- Where are the closest Shopping Centers?
- How do we cater for Public Transport?
- What is the distance to the nearest Schools?
…these are some important questions developers must consider while managing the collection of detail to design the proposed site to build a new state of the art community.
The engineer and designer should consider Carlson Civil Suite to produce a dynamic (concept to finish) subdivision design. Designing a community is a dynamic process; at any time during the design; lot size, road width, drainage size, surface model shape can be modified and upgraded automatically.
Utilizing the LotNet feature, all aspects of the design are interlinked; dynamically updated within the configuration constraints and changes can be saved as designs for comparisons. The tools to modify lot size by a small percentage to provide the developer with added potential to cover unforeseen costs without incurring an imposition on the design process is a great feature. All Annotation and reporting is automatically updated as the Process button is selected. Reports and spreadsheets are produced automatically.
The survey data file is the database for the design, typically as the design develops or changes the changes are automatically added to the survey file so the deeds, roads and drainage can be staked out as designed efficiently by copying the design back to the field computer.
Drainage and Catchment
As the climate changes, the designer must consider the need to manage the additional load of flash flooding. This means making provisions for parks or grassed areas designed as holding basins to hold a percentage of flood waters onsite releasing it slowly, this allows existing drainage to cope without flooding; the extra water released over a time span accommodating city drainage capacity.
These tools are included in Carlson Survey and Hydrology to integrate drains, pipework and catchment basins into the design model. As the designer changes the surface model, so does the drainage design update. Any conflicts or anomalies are reported in real time.
The roads within a subdivision should be designed to provide safe passage for standard width cars and SUV’s. Morning and evening rush hour traffic demands, plus access for emergency vehicles must be considered, including roundabouts and cul de sacs for faster, safer access and exits…eliminating bottlenecks.
Developers and designers have a responsibility to produce a safe environment. The commercial return for the developer is important, however community responsibility for investment longevity for the deed/home buyer is equally important. Professional developers have done this well in many areas. When developing low cost subdivisions, developers have a moral obligation to design for public safety and changing social needs..
As the value of land increases, the pressure to reduce lot size is the compromise. The minimum size of lots should not fall below one hundred and fifty square meters. Lots below this standard should only be developed in temporary accommodation housing developments. In doing so, there should also be provision for communal parking areas to prevent obstruction of roadways; safe parking should be placed a maximum of one hundred meters from an owners lot.
Carlson Survey provides the automation to develop a complete subdivision solution (LotNet) including automated lot design with configurable size and orientation, roadways,parking, kerbs, storm water drainage systems all linked to the topographic model. Configuration files allow the designer to change settings to achieve different scenarios at any time until the final design is approved.
A road verge can be included as part of the roadway to allow cars to be parked adjacent to housing. Development should include 7-10% of the total subdivision area as parkland and community walking trails and open space play areas; building safe happy and active communities….NOT ghettos.
The New Community
Space and the Natural Environment are two most important features attracting people to a subdivision. This should be both perceptive and real. Strategic positioning of large and small trees and grassed areas produces the concept of space and friendliness. The higher the density of housing the greater the risk to security and the value of the housing within the subdivision maintaining value and acceptance.
As we approach design for the 21st century every effort should be made to avoid over population. Too many people in close proximity; humans by there very nature demand space. If they are denied their own space, people will encroach on that of others….this leads to security, law and order issues and increased cost to communities.
I hope we can contribute in some small way to help design better communities in the Philippines…We are here to help in anyway we can to make life and your work as Developers and Designers easier and more successful.
Call us and we will assist in selecting software and hardware…or just a helping hand!