Sustainability and energy efficiency
To the editor:
Andrea Murray’s article in the Aug. 1-Aug 14 NHBR was very good (“Integrated design strategies for sustainable buildings”) as far as it went, but was lacking on energy-efficient design needs.
At this time of heating oil being 20 times the cost when most current construction and insulation standards were set, it is about time to revise those old standards. It is relatively easy to improve insulation enough to totally offset the increase in heating costs, while increasing basic wall construction cost only 20 percent. That consists of using double 2×4 stud walls spaced apart to allow needed fiberglass insulation (very similar to the old successful New England ice houses, some still in use). Material cost for two 2×4 stud walls is about the same as for one 2×6 stud wall, but insulation ration can be over 20 to 1.
Natural “stack effect” ventilation is ideal, but should NOT be thru windows — windows should only be for light or view. For those purposes the window is NEVER in correct location for best ventilation. Needed vents can be built with as much insulation as the walls, and used only when needed. Non-opening windows can be cheaply built with insulation equal to fiberglass-filled 2×8 stud walls.
Daylighting may seem like a nice idea, but never works. You NEED good fluorescent lighting for night, overcast days, winter season, and the cost of that electric lighting is almost nothing compared to the cost of heat loss through windows.
With proper wall and window insulation, the need for air conditioning is minimized. In fact, if the base level is made with a crawl space instead of a slab, filtered air can be blown through that space for all the cooling and dehumidifying needed, so air conditioning can be eliminated, saving about half the yearly energy costs, and keeping that base floor warm.
With the above improvements, wall heights can be reduced by about two feet, with no need for air ducts above ceilings. That alone can reduce wall construction cost 20 percent, and heat loss thru walls by 20 percent