Energy Vanguard Blog

Designed to Earn the ENERGY STAR, Our First Design Project

Posted by EV Staff on Fri, Jun 4, 2010

A few weeks ago, my uncle, John, called me up and asked if I could design the house where he and his future wife would spend the rest of their lives. Like many people, he wants to save money on the construction costs and the energy bills. “No problem,” I said. 

That may seem like a case of John wanting to have his cake and eat it, too, but I'll discuss below how he really can have both.

After explaining the architecture process and establishing a program, I told him about the many ways that we could help him do exactly what he wants. If you're planning to build a house, read on to see how this process might help you as well.

One of John's requests is to save on the initial cost. Perhaps the best way to save on construction costs is by incorporating advanced framing techniques into the design. Not only does it save money by reducing unnecessary lumber, but it also results in a better insulated house.

We also won't specify items like photovoltaic (PV) panels, rain harvesting systems, or composting toilets. While we encourage these systems for conserving our natural resources, they tend to be big ticket items in the construction of a ‘green’ home when selected. (See our 5 Step Plan for Solar Energy for more about that.) 

To meet John's second mandate - low energy bills - we'll apply the principles of building science to ensure that that his home is tight and well-insulated. Since about half of a typical home's energy use is for heating and cooling, this will be the first thing we focus on. Along with a tight, well-insulated building envelope, one of the most important things that we’ll do is perform HVAC load calculations and duct design to help the heating and cooling equipment function as efficiently as possible.

Here, then, are some of the key things we're planning to incorporate in the design for my Uncle John and his bride, Ann, to help them reach their savings goals:

  1. Insulation – Spray foam insulations are rapidly gaining popularity and earning a good reputation for making a tight home but are relatively expensive. If spray foam is outside their budget, we'll specify blown or sprayed cellulose or fiberglass. Batts are difficult to install well and thus function poorly, so we steer clear of them whenever possible.
  2. Windows – The minimum here will be double pane, low-e windows, which are the standard now and required by code in many places. If John and Ann can afford the upgrade to the new type of window that has two panes of glass with a membrane between that acts like a third pane, such as the ones made by Serious Materials, we'll push them in that direction.
  3.  Advanced framing techniquesThese are techniques like ladder T-walls and 2-stud corners, which use less lumber in framing a house and reduce material costs. They also increase the level of insulation as a result.
  4. Air sealing – Identifying key points for air-sealing to prevent infiltration, which increases the heating and cooling systems loads and energy bills.
  5. HVAC load calculations (Manual J) and duct design (Manual D) – Performing these two services results in a ‘right-sized’ heating and cooling system and a duct system that isn't a liability. Good HVAC design is the second most important step after designing a good building envelope.
  6. Ductwork installation specifications – We specify that all ductwork meet the Manual D design, as well as be properly installed and sealed with mastic at all joints.
  7. HERS RatingThe home will be designed to meet a maximum HERS index, and then tested post-construction to ensure compliance.

 

As you can see, none of this work requires the installation of large or expensive equipment. Nor does it require a heavy maintenance regimen once John and Ann move in to the house, which was another requirement for their ‘green’ home.

Finally, what we'll be delivering to John and Ann, is a set of drawings, specifications, HVAC load calculations, and a home energy rating file. The whole package will be Designed to Earn the ENERGY STAR, a new program for homes going through the design process. If built according to these documents, they'll have a home that will be comfortable, beautiful, durable, and energy efficient, as well as qualified for the ENERGY STAR label.

Tags: home energy rating, ENERGY STAR, HVAC, design, insulation