New green building world: Tour a high-performance home - by Katrina Hill

Katrina Hill, Appraisal Institute

What is a high performance building? Green or high-performance buildings have six key elements: site, water efficiency, energy efficiency, indoor air quality, materials and operations and maintenance. (Source: Residential Green Valuation Tools, Sandra Adomatis).

Continuing education for appraisers comes in many sizes and shapes, and usually involves sitting in a classroom for hours while trying to assimilate all the new regulatory burdens. There is so much to know, even after years as an appraiser. Building codes are evolving; building construction is advancing and the appraiser sees new types of construction materials on a daily basis.

I recently had a continuing education seminar at Unity Homes (founded by Tedd Benson) in Walpole, N.H. to learn about high-performance home construction. A tour of the plant where the wall and roof panels are assembled was an eye-opener for even an experienced appraiser. The wall structure is panelized and appears quite different from conventional on-site stick-built construction. There were laptop computers at every turn, alongside the large milling machines. The plant has remarkably very little waste products in the construction process. We noticed only a few dumpster bins throughout. Much of the waste from milling and fabricating is recycled.

The end product is a small sustainable and affordable energy-efficient structure, very tight, with good soundproofing and requiring low energy costs to operate. The Unity home uses over 60% less energy than a typical IECC-Code home (note: NH uses the 2009 IECC-Code). The home can be brought to net-zero with the addition of rooftop solar panels or other renewable energy source.

These factory built homes are designed to be healthy for the occupant and healthy for the environment. In addition to allowing for natural light with passive solar orientation, I was drawn to the comment that the homes are sound-quieting due to the extra insulation in the walls and roof. The insulation used is dense-packed cellulose insulation because it has greater R-value per inch than fiberglass batting and performs more reliably than foam. Cellulose insulation is a green building product, requiring 10 times less energy to develop the finished product than does fiberglass insulation (when considering transport of the raw materials, manufacturing it and then distributing it to the user).

Framing in these homes is not conventional. The panels are large rectangular boxes filled with cellulose blown in to the cavities. The interior wall has a service chase (pocket for the electrical and plumbing, just inside the insulated wall. The panels are fabricated and then wrapped for shipping and assembled on site with a crane. The walls are thick and R-35 insulated with the ceiling up to R-48.

When touring the model home, it was evident that traffic noise was diminished when inside the structure. The indoor air quality is managed with an air exchanger. Additionally, no VOCs are used in the construction (Volatile Organic Compounds), which are a major health hazard.

National studies have shown that energy efficiency can increase a home’s value from 0%-7% or more. That is, a buyer will pay a premium for these features. The challenge for the real estate appraiser in valuing high-performance homes is to analyze if and how much these features contribute to market value.

Katrina Hill, SRA, is the 2016 president of the New Hampshire Chapter of the Appraisal Institute and a certified general appraiser with R.B. Hill Company, Sunapee, N.H.