The Details of the Design
Finally an Affordable, Buildable, Certifiable home built for the way families really live.
By Manny Gonzalez, AIA, LEED AP
Sustainable design has made its way into the building industry over the last decade or so and continues to gain momentum. There have also been several net-zero energy prototypes built around the country, some as demonstration homes by builders and others as an experimental structure by university students. The ABC Green Home goes beyond an experiment — the vision of the “ABC” Green Home design team is to create an Affordable, Buildable, Certifiable home: affordable to the widest range of home buyers possible, buildable anywhere in the country and certifiable by any rating organization.
The design team also took on one more challenge, incorporating Universal Design. The goal was to create a family home with at least three bedrooms and a flex space, yet keep it less than 1,700 square feet to maintain affordability. The decision to make it a single-story home was driven by the desire to make the entire house accessible, and because a home needs to be over 2,000 square feet before a two-story plan becomes more cost effective. The home is designed for an alley-loaded condition, however, as a result of the buildable layout, the living side of the home can be flipped over to create a front-loaded plan with the exact same room features as the alley-loaded version.
With the intent of creating a starter home, the main living area is a great room plan. The kitchen is no longer something to be hidden; it is the hub of the house. The flex room up front could serve any number of functions that a young family could want, from formal living or dining, to a home office that could have a separate entrance on the front, to even a kids’ playroom. However, perhaps the most important feature of this affordable starter home is the storage. Today’s young family doesn’t shop the way they did when the homebuilding industry came out of the last recession some 20 years ago; this generation buys in bulk. They shop at Costco, which is the reason the home features a “Costco Pantry” with substantially more storage than one would usually find in a home of this size, as well as an oversized laundry room with room for all of those 24- packs of dry goods.
The footprint of the home is a very efficient, almost square house plan that allows for the shortest mechanical runs possible. A two-car garage is attached to the home, but unlike most homes, the access isn’t through the laundry room but off the back porch. This keeps the most toxic fumes found in a home, automobile exhaust, out of the living space to allow the residents improved air quality. The overall dimensions are whole feet and, where possible, whole feet measurements are used throughout to allow for modular construction with minimal waste.
Additionally, the interior dimensions have been programmed to minimize construction waste, with measurements in inches of zero, four, six or eight. The exterior walls are constructed of two-by-six boards to provide room for added insulation, yet at the same time, since the studs are stronger than the conventional two-by-four exterior, they can be placed at 24 inches on center, thus using less lumber compared to the way homes are traditionally being built today. These are all simple practices that require just a little more discipline on the part of the architect to incorporate, but as we recover from this recession and the echo boomers begin to enter the home buying market by the millions, the impact could be huge.
There was considerable debate among the design team about plate height and ceilings, however, with the desire to create as tightly insulated a living space as possible, it was decided that all the mechanical ducting would be placed in soffits in the hallway of the home. Wanting the hall ceiling height to be at least eight feet, without creating a volume ceiling in the great room, a nine-foot plate with a flat ceiling was chosen for the home. This also allowed for an easy increase in the attic insulation and the use of blownin material.
While important to the affordable, buildable and certifiable aspects of the home, the homeowner doesn’t see the studs, or insulation or ducting; their concern is the overall look of the home. Most of the experimental and demonstration net-zero energy homes are a contemporary design, and the first concepts for this home were contemporary as well.
Since the first ABC Green House was to be built in Southern California, where singlestory bungalow Craftsman style homes can be found from Oxnard to Ontario, this was the style of architecture chosen for the inaugural home. The front porch, a traditional part of the Craftsman home, not only creates an inviting street scene, it results in a heeled truss at the plate line of the conditioned space allowing for added insulation at this critical area. With a desire to create outdoor living space, a large optional rear porch provides a real space for the family to gather and dine, while also providing protection from weather when exiting the garage.
Production homebuilding has not changed much in its means and methods since the industry began, and the ABC Green Home uses the same means and methods that any of today’s home builders would, it just uses them in a more affordable, buildable and certifiable way. The simple footprint and roof form keep it affordable, yet the simple architectural detailing the design can be quite aesthetically appealing to the broadest buyer market. The modular dimensions make the home quite buildable, so much so that when construction begins, many of the elements will be built off site by students as a part of their education. Simple changes in the way we build, like using two-by-six exterior framing at 24-inch centers to reduce lumber and waste, while at the same time increasing the home’s energy efficiency, make the home easily certifiable.
As we take the ABC Green Home into the reality of the future of home building, I hope you will follow along with us to see how the next generation of home building is taking shape — creating a healthy and sustainable living environment for tomorrow’s homebuyers.
Manny Gonzalez, AIA, LEED AP and CAASH is the senior partner with KTGY Group Inc., Architecture and Planning. He may be contacted at firstname.lastname@example.org.