Coving: The Future in Single Family Design
Adrienne CarrigerEditor's Note: This is the last article in a four-part series on "coving," a new technique in subdivision design developed by Richard Harrison.
This article will describe a street layout method called "windings" that should be used with meandering coved lots described in the November/December 1997 issue. Winding of streets can be used without coving to save linear feet of street and utilities. However, it can create spectacular neighborhoods if combined with coving.
The winding street layout reduces the number of streets within a development, minimizing the possibility of "getting lost" in a subdivision. The neighborhood also becomes safer as the number of intersections is reduced. Because little street (if any) is used for side yards it can reduce or eliminate viewing home rears when driving along streets.
To understand how windings work, look at a standard subdivision (Figure 1). This 44-acre development has 200 60- by 100-foot lots (6,000 square feet). The minimum allowed width is 50 feet at the front setback. This standard development contains 8,400 linear feet of street, of which 3,050 linear feet is constructed along lot side yards. Allowing for a 50-foot-wide right-of-way (ROW), 1.75 acres of land are wasted for side frontage that could have been used in lot size. The site features nine streets, 14 intersections and two cul-de-sacs. Each cul-de-sac is the equivalent of 170 linear feet in extra pavement. The worst part of the standard design is the featureless way the homes are aligned along the street (Figure 2).
Now look at the same site with a winding street pattern along with coved lots (Figure 3). In this case the street stretches, providing a greater "frontage" area with little exposure on the street for side yards.
Cost Savings with the Winding Technique
The winding technique saves more than 2,400 linear feet of street compared with the conventional layout. The 50-foot-wide ROW causes a gain of 2.75 acres in lot area, which by combining winding with coving is added to the front yard space.
Supposing that roadway cost is $150.00 per linear foot (including sewer), this development could cost $360,000 less to construct with the combined winding and coving techniques. Virtually all new street is used for lot frontage, making each construction dollar work for density. This development is also much easier to navigate, with a total of five intersections and three streets, and is also safer with the curves and the lack of four-way intersections. Drainage run-off problems are also reduced. As for density, this layout gained two lots in relation to the conventional development.
This layout uses 50 feet as the minimum width at the setback, and the common park was eliminated because the 13 acres of front yard space make the street itself a "park-like" environment. Because homes are either not parallel or staggered when they are parallel (Figure 4), the actual or perceived distance between homes is greater. The average lot size on this layout is almost 2,000 square feet greater than the 6,000-square-foot minimum.
The winding technique can be used without coving. Coved lots, with their varied setbacks, are deeper, so the streets do not have to "hug" outer boundaries, further reducing linear feet of street compared with conventional lots. Coving stretches the available frontage regardless of street design. If this same site used the winding street pattern with conventional 60-foot-wide lots, there would be a reduction of about 10 lots (at 50 feet wide) with a reduction of 2,000 linear feet in streets. The developer would still be ahead financially.
When presenting a coved subdivision, the developer should avoid showing a "plat". Although coved plats are prettier than normal subdivisions, a standard plat does not show the full effect of coving. The most effective way to show the development is to show the improvements on the site such as homes and driveways as in Figure 4. Highlighting the front lawn space in green and showing a comparison to conventional plans can also help.
The developer should avoid complex terms when presenting the subdivision. The main focus should always be that coving brings value to everyone. Increased lot sizes and home settings improve views within the development, creating a park-like setting for all homes.
Anyone who has the time and resources can assemble HO scale homes from model railroad stores and plot sample streetscapes at 1"=8'. This is an extremely effective way to get approvals. An easier and more affordable effective method is to buy several Monopoly sets, which will provide an abundance of homes that can be placed on color renderings of the plans.
Those who have a spatial software package that can easily compute and fill areas such as driveways, lawns and so forth, can fill and color areas that are visual. Spatial software allows different aspects of the development to be emphasized easily.
The experience of Rick Harrison Site Design has been that coved developments presented properly get very quick approval. Why not? They are superior to standard subdivision design.
This is the last article in the four-part series on the coving method of design. When land is subdivided it sets the environment for centuries, so it is an awesome responsibility to assume. The surveyor can make the environment marvelous or mundane, and coving will leave a legacy for several generations to enjoy.
Adrienne Carriger is the marketing advisor for Rick Harrison Site Design in St. Louis, Minnesota and can be reached at email@example.com