Finished attic

Jamb Detail for New Skylight

Posted on March 06,2015 by Peterbilt in kitchen and bath

Whole-House Fan Air-Sealing Details

Posted on March 06,2015 by Daniel Morrison in Finished attic

How to Build an Insulated Cathedral Ceiling

Posted on March 06,2015 by user-756436 in cathedral

UPDATED on September 12, 2014 Although the GBA website already contains many articles on the topic, we continue to receive frequent questions about the best way to insulate a cathedral ceiling. It’s therefore time to pull together as much information on the topic as possible and publish it in one place, to clarify the building science issues and code requirements governing insulated sloped roofs.

Don't Try This At Home: Armchair Building Science

Posted on March 06,2015 by Peterbilt in air leakage

The homeowners called me after a certified home inspector stated that the attic was underventilated and moisture was building up as a result. The roof assembly had soffit vents at the eaves and two gable-end vents. These vents would not be as effective as ridge-to-soffit ventilation, but were probably close to building code requirements (see Green Basics – Attics).

Green Remodeling is a Process of Discipline and Discovery

Posted on March 06,2015 by TommyStrong in green home

When you're talking about building and remodeling three words should be part of the conversation: Green, smart, and quality. Some parts are up to consumers, some are up to us. We guide the discovery process and use a disciplined construction process to boost value whatever shade of green our clients aim for.**

Heating and cooling the outside

Posted on March 06,2015 by Daniel Morrison in What's wrong with this picture?

What's wrong with this picture? **a)** The air handler and duct work are in the hottest and coldest part of the house. **b)** The wall insulation isn't working. **c)** There's more insulation on the wall than on the ductwork. **d)** All of the above. I wonder if the people who live in this house have young kids. And I wonder if they ever say to those young kids "Close the door, we're not heating (cooling) the outside." I used to hear it from my Mom, and I'm sure most every other person since the cave man days has heard it too.

If you must ventilate during construction, change HVAC filters often.

Posted on March 06,2015 by Peterbilt in Add a floor above

**During construction (renovation or new construction), building air is full of dust and volatile organic compounds (VOCs).**

So, it’s best not to run the HVAC system at this time. Just, seal the openings and leave the system off until work is complete.

Remove organic waste from walls and crawl spaces

Posted on March 06,2015 by Peterbilt in Add a floor above

**Don't leave wood chips or sawdust in wall cavities or crawl spaces.** This organic matter can promote mold growth. Decomposing wood also can attract termites and carpenter ants.

Further Resources

Building Science Corp. [Mold–Causes, Health Effects and Clean-Up](http://www.buildingscience.com/documents/reports/rr-0211-mold2014causes-health-effects-and-clean-up/view?topic=/resources/mold)

Install windows and skylights that lower solar heat gain in hot climates

Posted on March 06,2015 by Peterbilt in Add a floor above

**Keep sunny rooms from overheating by using windows and skylights with low solar heat gain coefficients (SHGC).** These range from 0 to 1. A value of 0 blocks all the sun's energy–lower SHGCs are better for warm climates because they lower air-conditioning costs. A value of 1 means that none of the sun’s energy is blocked by the window. Higher SHGCs are better for homes in cold climates because more solar heat gets through, which reduces heating costs.

Be fussy about flashing and sealing windows and skylights

Posted on March 06,2015 by Peterbilt in Add a floor above

**Leaky windows and skylights cause structural and indoor air quality problems.** Water leaks are expensive to fix and can cause major damage. Air leaks result in heat loss and unwanted moisture-laden air entering the home. Thorough attention to flashing and air-sealing here is important. Follow practices recommended by building scientists. See the articles below.

Design the building envelope to avoid thermal bridging

Posted on March 06,2015 by Peterbilt in Add a floor above

**Avoid thermal bridging through careful insulation detailing.** This reduces energy loss and moisture damage to wall assemblies. Avoid low R-value materials.

Balance air pressure with transfer grilles

Posted on March 06,2015 by Peterbilt in Add a floor above

**Balanced air distribution means a more comfortable house.** HVAC systems that use heating and cooling ducts are susceptible to pressure imbalances that can lower indoor comfort. Transfer grilles are a simple way of equalizing pressure from room to room. When noise transmission is a potential problem, consider grilles with baffles to muffle sound. Dedicated return ducts in each room or jumper ducts are other options. For more information on transfer grilles, see "Return-Air Problems."

Use skylights that lower solar heat gain

Posted on March 06,2015 by Peterbilt in Add a floor above

**Skylights let in natural light, but they also overheat some rooms.**

Because skylights are so popular, appreciating their full impact, both positive and negative, can be a challenge. Counteract overheating with low solar heat gain coefficient (SHGC) glazing. The National Fenestration Rating Council (NFRC link below) has guidelines for optimum performance for both U-Factors and SHGC.

Bring in more light with skylights and clerestory windows

Posted on March 06,2015 by Peterbilt in Add a floor above

**More light makes for a cheerful, healthy interior.** Brightly lit interiors also cut down on the need for electric lights, an energy savings. Skylights are usually less expensive than adding a clerestory, which can require elaborate roof and wall framing. One caution: both skylights and clerestories can increase solar heat gain and glare.

Learn more in the Green Building Encyclopedia

[Sun: Passive Heating and Daylighting](node/11548 "Design Around the Sun to Lower Heating and Lighting Needs")

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