Where does NAHB Green rating system fit in the process of building an energy efficient house? I have often compared ENERGY STAR homes built by master builders to the delights of a master chef who prepares meals to “die for.” The experience of a master, the quality of ingredients, the right equipment, and most important the correct plan or recipe produces extraordinary results. It takes all of these things to produce great chocolate chip cookies OR great houses. So where does the NAHB Green rating system fit in? It’s easy. The NAHB is more of a full meal deal, a gourmet meal that is.
National Association of Homes Builders has a proven program that goes beyond an energy efficient house. It is like a complete meal with all the extras. Inside the NGBS, the National Green Building Standard, we find that ENERGY STAR is still the core of the energy section. But there is much more.
- Lot Selection and Construction – gives guidelines for choosing the best possible site and directions to protect your site as you improve it.
- Resource Efficiency – guidance on selecting the correct reproducible path and how to protect what you built from old, wasteful practices.
- Energy Efficiency – based on ENERGY STAR with lots of added prescriptive concepts and guides.
- Water Efficiency – showing step by step techniques proven to save a valuable resource.
- Pollutant Control – aids in the unseen area of good air quality and moisture control.
- Operation and Maintenance – through owner education and a collection of material provided to the owner on how to keep the efficiency of a green home at an optimum level.
Each of these sections is broken down into points, 600+ with minimum requirements in each category. This helps keep the project in balance. It is easy to focus all the attention on one area, like energy, and forget about durability. This is a major issue today. If left out, time and nature can ruin all the extra work on energy. This is so important that ENERGY STAR has recently added durability issues, like water management to its rating system. NGBS has always had it, and provides detailed credits to keep water and moisture out of the places it can do harm. For example, I have seen many damp and wet crawl spaces resulting from lack of attention to certain details during the first day of construction. Issues easily avoided, but often overlooked.
The NGBS Standard (NAHB = National Green Building Standard ICC 700-2008) is the only ANSI approved rating system for residential construction. It is connected to the professional builders of the NAHB and building inspectors with the ICC (International Code Council). But the system is for anyone to use. The rating system is what I call “builder friendly” in that it is written in the way contractors work. This rating system is written by builders for builders, based on the latest building science principles with a local third party verifier who is overseen by the National Research Center in Maryland.
A gourmet meal, like a well-built energy efficient house, is comprised of various components that must work together.
- The ICC700 Standard gives the recipe
- The builder provides the experience
- Third party verifier provides the inspections (without being connected financially to the project).
This is how we determine how green is green, or how efficient is efficient. The result of the rating is a national certification ranging from Bronze, Silver, Gold, to Emerald.
Jim D. Baker, HERS Rater, NHAB Green Verifier, Green Rater and LEED AP for Homes.