July 17, 2009

Making Your Home Energy Efficent: Modular Homes

by Environmental Building Strategies in Energy, Green Building Tags: energy, Green Building, Modular Homes 1 Comment

I am not sure how many of you read the recent article in the San Francisco Chronicle about a net zero modular multi-tenant townhouse being built by a bay area company. I am very glad that this article made the front page especially on a day when Michelle Obama visited San Francisco. It just goes to show you the importance of green building in the bay area.

This article made it seem that modular homes were an unusual medium for energy efficient building. If you look at the facts, modular homes are just as easy if not easier to make efficient compared to regular construction. The same measures that are devised to make a typical residential home energy efficient are similarly implemented in modular homes. These include, but are not limited to, using high grade insulation, high efficiency appliances, utilization of active and passive solar solutions for heating, energy production, and natural lighting, as well as innovative strategies to employ existing conditions within a house to improve energy efficiency. This last category is where I saw the most unique and creative measure utilized by the company in the article. They implemented a wastewater heat recovery system that preheats shower water.

What makes modular homes a great form for sustainable building is the construction process. Having a standard prefabricated design cuts down on waste and the energy used during construction. It also allows designers to implement the same energy efficient solutions to each house quickly and easily.

The process for making any home energy efficient can seem daunting and complicated but two easy steps can be taken to get you started.

Maybe the most important is energy efficient appliances. When you are constructing a new home make sure you look for ENERGY STAR rated appliances. The initial cost may be slightly higher for these appliances, but they can save you significant energy costs and have substantial rebates attached with them. Considering that kitchen and laundry appliances account for a third of a house’s energy load with central air-conditioning adding another 15 percent, conserving even a small amount of energy with energy efficient appliances can result in huge savings.

Another important aspect to consider is the geometric placement of your house. The sun’s rays penetrate the most from the south. As the sun rises in the east and sets in the west it is seen in the southern part of the sky at high noon. In the summer when cooling loads are very high energy costs are also more expensive. To solve this catch 22 you can do several things.

First, make sure the windows on the southern exposure have low U-value glass. U value is the amount of heat the window transmits; lower U-values mean less heat is transferred. One of the best types of glass that has come out recently is spectrally-selective glass. This glass lets only certain wavelengths of light in cutting down on heat gain while not sacrificing the amount of natural light coming into your building.

Secondly, shade the south facing windows with plants, artificial shading, or for the best results solar panels. Shading windows will cut out, almost entirely, heat gain during the summer, and if done right will still let in sunlight and its heat in when its needed, during the winter.

Solar cells provide shading for windows or help keep roofs cool while also generating electricity for the house. Though expensive, Photovoltaic cells are a key aspect in trying to make your home net zero. PV cells should come farther down the line in the process as energy efficient measures should be implemented first.

With these easy steps, you can be on your way to making your modular home or regular home as energy efficient as possible. This will help you comply with the new mandates and save you a ton of money. Being ahead of the game is very important, especially down the road when the 2020 deadline for making all residential buildings net zero comes along.

This is a green modular home designed by MOD-ECO Architecture.

–The EBS Team–