Thermal Control

Providing thermal comfort without excessive HVAC systems is one of the primary goals in green building.  To accomplish this goal, it is important that the builder understand heat transfer, and temperature control through wall and roof assemblies.  A thermally controlled home is an efficient home.  High efficiency not only results in low utility bills, but also a more comfortable indoor environment.


Reduce Thermal Bridging

Thermal bridges (framing material) can reduce the efficiency of the home, and should be kept to a minimum.  Wood can act as a “bridge” drawing heat out of the building in the winter, and drawing heat into the building in the summer. Remember this- where there is wood, there can be no insulation. It is a common habit for framers to “build stout when in doubt,” installing more framing material when unsure. But more wood is not always better. Point loads, shear loads, and headers should be calculated and clearly marked on plans, and excessive framing should always be eliminated. Measures to reduce thermal bridging include:

  1. •Double wall construction

  2. •24” on-center framing

  3. •Header hangers

  4. •Stack framing

  5. •2-stud corner framing

  6. •Raised-heel trusses


Other Thermal Control Measures

  1. •High quality blown-In insulation

  2. •Super-insulated foundations (R-20)

  3. •Super-insulated walls (R-40)

  4. •Super-insulated roofs (R-60)

  5. •Insulated exterior sheathings

  6. •Efficient windows

  7. •Spray foam air sealing

FRAMERS SHOULD THINK STRUCTURALLY AND THERMALLY

BUILDING SCIENCE

Moisture Control

Airflow Control

Thermal Control