How much does green construction add to the cost of a new home?


How much does green construction add to the cost of a new home?

Asked by Larry Chamblin, Pensacola, FL

My wife and I plan to build a retirement home in western North Carolina we have in mind a three-bedroom house under 2,000 square feet. I want green and healthy construction my wife says we can't afford "bells and whistles." I know there are many factors that go into cost, but all other things being equal, what can we expect green construction to add to the cost of a new home?

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Polly Osborne, FAIA, LEED AP's picture

I think I can make an argument that building green will turn out to be cheaper for you in the long run. First, let's discuss what green building involves: resource efficiency, energy efficiency, and indoor air quality.

Resource efficiency is the worth of a product in the big picture. How many natural resources does a material use? Can it be reused or recycled? Can that recycled use be the same quality or better than the original? How long will the material last?

Energy efficiency includes the embodied energy to make a product and how much energy it takes to use it.

Indoor air quality must also be taken into account. For some people and some climates, this aspect of green building takes on more importance. Now let's look at some cost-saving ideas for each of these categories.

Resource efficiency

The best way to be efficient with materials is to build no more than you need. Next, consider the quality of the materials you use. Although Forest Stewardship Council (FSC) certified lumber costs about 10 percent more than other stocks, in my experience the lumber is of higher quality. Also, the FSC is a third-party nonprofit review agency that certifies sustainably grown lumber. It is worth insisting on this certification, as there are others that are basically voluntary systems that fall under the category of "greenwashing" (looking green without really being so).

Engineered lumber is also an option. It's slightly more expensive, but it's straighter and truer than natural lumber, which results in a higher-quality building. Also, workers spend less time fighting crooked walls and uneven surfaces, so using engineered lumber saves on labor costs.

When we start a project, we get to know what resources are locally available. Is there someone who salvages wood from old barns? Perhaps there is a great metalworker nearby. (Steel is a 100-percent recyclable product.) Also determine if there is a green network in the design and building trades of people already committed to the project. You can save money by using professionals who are familiar with the resources used. Contractors have a healthy suspicion of things they haven't tried before and that can result in a higher bid. But the greatest cost savings is having a well-informed and diligent owner.

Energy efficiency

Passive solar design is free and not only saves energy, but also results in an immensely comfortable home. My advice is to do a serious site study on any lot you find. Bring a compass and wind meter along with you (or at least wet your finger and see which way the wind blows). Natural heating and cooling will both be important in North Carolina. These are design issues that involve local research. Wind chimneys or earth heat exchangers can cool a house, but you need a design team that understands these options. A simple low-cost method for reducing cooling loads is to include a whole-house fan in your design. When you buy the elements of electrical systems, plumbing and appliances you will find energy efficiency ratings well established for many products by the Energy Star system.

Indoor air quality

In paint, you can usually buy a company's environmental products for the same cost as their other lines. Construction quality is key, however. A house with poor flashing, leaky windows or improper material separations can quickly develop a mold problem. In most cases this is a matter of knowledge and experience on the part of your design and building professionals. It isn't an initial cost issue so much as a very expensive retrofit.

In conclusion, there are lots of wonderful opportunities to buy beautiful green products, from lovely salvaged wood full of character to sparkly recycled glass tile, all of which may or may not be more expensive than an equivalent standard product.

First, though, you must make some very basic choices about where to build and how to maximize the site and building to create beauty and harmony, heat and cool the house naturally and save on resources.

Contractors accustomed to green building generally tell people to estimate 10 to 15 percent more expense when doing green building.

This extra money is due largely to the higher cost of certified lumber, the higher labor costs involved in using recycled products, and better quality manufacturing to achieve efficiency and durability.

For more information:

Click here to download a PDF version of a cost analysis developed recently for one of my own projects. This PDF compares green materials and systems with their conventional counterparts, additional cost/savings, and payback period.

You can learn more about your new "eco-address" -- meaning the ecology of your new neighborhood -- at North Carolina's Office of Environmental Education website.

Consult North Carolina's Division of Waste Management website for information on recycling and safe disposal of construction waste.

For more information about sustainably harvested lumber, visit the website of the Forest Stewardship Council.