Energy Efficient HousingWhy construct energy efficient structures?Model Energy CodeBasic Considerations:Shape of StructureR –Value as Related to Building Material FeaturesExamples of R- value’s (per one inch of material):Recommended R-values by regions:U - ValueFeatures to consider:Features (con’t):Orientation:Thermal Envelopes1Energy Efficient Housing2Why construct energy efficient structures?Bottom Line !!! MoneyIt may save up to 60% of the cost to heat/cool the structure3Model Energy Code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 efficiency4Basic Considerations:Shape of StructureStructural Features & Materials UsedOrientation5Shape of StructureIdeal shape is a squareIf the structure is long and narrow, it is less energy efficient6R –Value as Related to Building Material Features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 thickness7Examples of R- value’s (per one inch of material):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 6.08Recommended R-values by regions:0510152025303540Ceiling Wall FloorSouthMid WestNorth9U - Value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 lost10Features to consider: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 vents11Features (con’t):Continuous ridge vent or thermostatically controlled roof ventsMastic under base plateInsulated doors (R-10 min.)Insulated windows or storm windowsInsulate water pipes12Orientation: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 sun13Thermal Envelopes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