Green Re-modeling

The following is a summary of a talk I gave at the Charlotte NC "Clean And Green" Earth Day event. It tackles a subject that could easily be a week-long course, or a book, so much is left out, but feel free to contact me to discuss or comments.

If you own a home that wasn’t built to be green or energy efficient in the first place, then there are probably a lot of valuable improvements that can be made that can dramatically reduce energy bills and increase the comfort of your home.

The first step is to determine your appetite for remodeling and how much you want to do yourself.  Are you the kind of person who’s handy and wants to do everything on your own, or do you prefer to hire professionals to do the dirty work?  Either way it pays to know a bit about what you’re getting into and get involved in the decisions.

It’s also worth defining for yourself what aspects of “green” are most meaningful to you. I define green as having three components or facets, which are:
-    Energy efficiency
-    Health, particularly indoor air quality
-    Environmental stewardship

Energy is by far the most clear and immediate payoff. However health is a real and rapidly growing concern, especially for the increasing numbers of people with sensitivities to chemicals.

So the two most valuable renovation tasks you can undertake are sealing and insulating. Together this will save a huge amount of energy, and by taking better control of the air in your home you can improve the health of its occupants.

But also remember that the number one enemy of a house and your health at home is moisture. Moisture and warmth together with a foods source like wood or paper will encourage mold growth. And mold can be very damaging to your health, particularly your respiratory system.

Mold can be prevented by elliminating unwanted moisture and controlling air flow effectively. Hence, sealing and insulating will not only save you money on energy bills but, done right, can also prevent health hazards such as mold, mildew and pollen.

Sealing
Most older homes were build fairly loosely and this served them well to keep cool. But with the introduction of air conditioning builders have tried to tighten up the homes a bit more. However most homes still suffer from fairly sloppy construction and have numerous undesirable penetrations in the shell that allow outdoor air to leak in.

My priority is to start at the top and seal the attic floor to separate it from the living space below.  Sweep aside any loose insulation or lift up batts to inspect the places where light fittings are mounted below in the living space and seal any openings with caulk, or if the opening is larger than ½ inch wide, you can use a canned spray foam. Also inspect around any pipes or other penetrations of the living area ceiling and seal them in the same way. Then try to locate where the interior walls meet the ceiling and look for openings there. Often there are cavities or chases that allow air to circulate freely through the interior walls. This can allow hot attic air into your living space. If the openings are larger use rigid foam insulating board together with caulk to seal them.

Here are a couple documents that may come in handy if you're preparing to do this yourself:

Air Sealing Details

SystemVision Air Sealing Pictorial

SystemVision Duct Sealing Pictorial

DOE Duct Sealing Brochure

Insulating
The most cost effective insulation is fiberglass. If it’s properly installed (though so often it is not) it can be very effective.  You can now get formaldehyde-free fiberglass insulation, which is preferable. 

Another choice is cellulose insulation made from recycled newspaper. It us blown into place and often used on attic floors. It’s a better choice from a health perspective, though about equal to fiberglass in effectiveness. Remember that with blown in attic insulation it’s the air that provides insulation so if it’s compressed it will do much less good.

My prefered choice for insulation is spray foam, such as icynene, though it is up to three times more expensive than fiberglass. Its key advantage is that it seals while it insulates, and it lasts indefinitely. If your budget can stretch to it, using this in attics for renovations is a great investment. Alternatively, make sure which ever other insulation you chose is properly installed.

This document shows how fiberglass batt insulation should be installed.

Indoor Air Quality
The contributors to most indoor air quality problems can be addressed through proper sealing and insulating. But you should also be mindful of the contribution from cabinetry, flooring and furniture to volatile organic compounds (VOCs) in your air. Inspect closely the make up of any of these items you select, paying special attention to avoid formaldehyde, which is sometimes found in the adhesives that bind materials like particle board together.  One builder I know controls VOCs effectively by sealing the raw edges of  kitchen cabinet components to prevent the particle board from off-gassing. This can be a less expensive compromise.

Remodeling Priorities and checklist
Below is a summary of many of the projects we discussed and it shows my approach to priorities working from the simplest and cheapest projects to the most complex and costly. So choose how far to work down the list according to your budget, appetite for renovation and your determination to create a high-performance green home.

Small Easy Projects for Energy and Water Savings

• Programmable Thermostat
• Compact Fluorescent lights
• 1.6 GPM Showerheads
• Rain Barrels
• Fix leaks
• Seal Duct leaks (Duct Mastic)
• Seal Attic floor penetrations (Caulk & Spray Foam)
• Seal other leaks (gaskets and caulk)
• Water Filter – mine is a Multi Pure but there are some other good brands

Medium investments and projects

• Low flush 1.6 gallon toilets, or better yet, dual flush toilets
• Energy Star water efficient Dish Washer (save 25%)
• Window Film from 3M that cuts heat gain
• Insulation (Attic, Crawlspace)
• Tankless (or On-Demand) water heater
• Deciduous trees to shade Southern exposures
• Tubular Skylights to bring in natural light
• Grey Water Recycling – Brac Systems
• Replace carpeting with hard flooring or non-toxic carpets
• Composite or FSC Teak Decking

Larger investments and projects

• Windows - Low E
• Energy Star Washer
• Energy Star Refrigerator
• Light colored or metal roof
• Radiant floor heating
• Solar Hot water
• Water Cistern
• Solar Photo Voltaic  (electric)

Key Behaviors

• Clean or replace HVAC Return Filters regularly – monthly
• Use ceiling fans when in the room (turn off when not in the room)
• Turn off lights when not in the room
• Unplug wall warts – UCB Lawrence Labs estimate 10% of home use
• Using kitchen and bath extractor fans to remove moisture
• Heat Pumps – avoid sharp degree increases (3 deg max)
• Compost vegetable trimmings

Online Information Resources

• Energy Star – www.energystar.gov
• Advanced Energy – www.advancedenergy.org
• Energy Efficiency & Renewable Energy (DOE) www.eere.energy.gov/consumer/
• Joe’s Top 10: www.buildingscience.com/bsc/topten/south.htm
• Green Home Guide (USGBC) www.greenhomeguide.org/index.html
• (look for green remodeling and green renovation checklist)
• The Green Guide (National Geographic) www.thegreenguide.com
• Green And Save (ROI tables for renovation) - www.greenandsave.com
• Practical Eco (NC Green Building Blog and products) – www.practicaleco.com