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Energy Efficient
Housing
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Why construct energy
efficient structures?
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Bottom Line !!! Money
It may save up to 60% of the cost
to heat/cool the structure
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Model Energy Code
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A national minimum standard for
energy efficient residential
construction developed by CABO
(Council of American Building
Officials)
Incorporates the use of select
building materials to maximize
energy efficiency
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Basic Considerations:
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Shape of Structure
Structural Features & Materials
Used
Orientation
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Shape of Structure
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Ideal shape is a square
If the structure is long and narrow,
it is less energy efficient
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R –Value as Related to Building
Material Features
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R-Value defined: a numerical
measure of resistance to the flow
of heat; the higher the R-value, the
greater the resistance to heat flow
Specific resistance of any material
is directly related to it’s thickness
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Examples of R- value’s (per one
inch of material):
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Batts or blanket insulation – 3.14
Rigid board insulation – 3.8 to 4.8
Cellulose (loose blown) – 2.8 to 3.7
Extruded polystyrene – 4.0 to 6.0
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Recommended R-values
by regions:
40
35
30
25
South
Mid West
North
20
15
10
5
0
Ceiling
Wall
Floor
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U - Value
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The number of BTU’s (British
Thermal Units) per hour that will
flow through 1 sq. ft. of the
structure when there is a 1 degree
difference in temperature between
the 2 sides.
The higher the U-value; the more
heat will be lost
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Features to consider:
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6 “ exterior walls ( 2”x 6” @ 24”o.c.) R- 19
12” insulation in ceiling R-38 (min. 30)
Extended overhang (30” to 36”)
Insulate slab
Insulate between floor joists (6 “)
Heat ducts inside heated area
Install dehumidifier
Heat pump
Continuous soffit vents
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Features (con’t):
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Continuous ridge vent or thermostatically
controlled roof vents
Mastic under base plate
Insulated doors (R-10 min.)
Insulated windows or storm windows
Insulate water pipes
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Orientation:
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Try to build narrow end of building
running East and West because of
the greater heat gain from the sun
In winter, windows on the South
side of the structure will catch
“free” heat from the sun
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Thermal Envelopes
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Any exit or entry point in the
envelope is a potential place for
heat to enter or escape.
Seal all such locations with the
appropriate materials/methods.
Examples: around doors (weather
stripping)
Can you think of other areas of
concern ?
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