Building Technology Options

You have much to consider when designing and building a new sustainable energy-efficient house, and it can be a challenge. However, recent improvements in building elements and construction techniques allow most modern energy saving ideas to be seamlessly integrated into house designs while improving comfort, health, and aesthetics. Even though some energy-efficient features are expensive, there are others that many home owners can afford. While design costs, options, and styles vary, most energy-efficient homes have some basic elements in common; a well-constructed and tightly sealed thermal envelope; controlled ventilation; properly sized, high-efficiency heating and cooling systems; and energy-efficient doors, windows, and appliances.

For new homes, there is no single best design or technique for achieving optimal energy efficiency. Builders now have a vast array of materials, components, appliances and techniques. Quality work and good materials have always been hallmarks of a well-built home but an understanding of how a house operates as a system is essential in building an energy efficient home. Knowing how to properly integrate all of the building components and understanding that they all interact is necessary in order to produce a high performance home.

Build an ENERGY STAR Qualified Home for more comfort and savings. An ENERGY STAR home is built to be more efficient than the current International Energy Conservation Code (IECC) and is backed by the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). To qualify, the home must be evaluated by a nationally-accredited Home Energy Rating Systems rater. For more information on ENERGY STAR homes please view: www.energystar.gov, and to find Raters view http://www.neo.ne.gov/hers/hers.htm.

Building Components Checklist

This cut-away house show a home’s thermal shell and building components — the “Systems Approach” to building a new home. Optimum efficiency cannot be achieved by selecting only a few quality components. The overall plan must be considered.

For more specific information on building science, use the Home Energy Suite Tool. Then go to the “Home Energy Library.”

Each building component is classified as “minimum”, “better”, and “best”. The “better” and “best” construction indicated may qualify towards an ENERGY STAR home.

Minimum: Meets the minimum requirement of the Nebraska State Energy Code, IECC 2009.

Better: Each component is upgraded to higher R-Values, better construction techniques and/or higher heating and air conditioning equipment efficiencies.

Best: The latest building science principles and products are used in all components to achieve the highest possible R-Values with advanced air sealing applied to the thermal enclosure, highest heating and air conditioning equipment efficiencies, moisture control, and mechanical ventilation.

buildingtechnology

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Introduction

Basement Floor

Minimum:  4-inch concrete floor
Better:  4-inch concrete floor with drain tile and sump pit, min 6-mil poly with taped seams
BEST:  4-inch concrete floor, exterior / interior drain tile sealed radon mitigation sump pit system, 4-6 inches of aggregate, min R-10 XPS (Under-Slab) insulation on all edges and beneath entire floor area, 6-mil high-density  poly with taped seams

Slab on grade including walkout basements

Minimum:  4-inch concrete floor, R-10 insulation from slab edge two foot vertical or insulate slab edge and two feet horizontal – on all sides
Better:  4-inch concrete floor, R-10 insulation on all slab edges and beneath entire floor area, min. 6-mil poly with taped seams
BEST:  4-inch concrete floor, 4-6 inches of aggregate, min. R-10 XPS   (Under-Slab) insulation on all edges and beneath entire floor  area, 6-mil high-density poly with taped seams  

Floors over unconditioned space including cantilevered floors

Minimum:  R-30 cavity insulation with subfloor contact or full cavity insulation minimum R-19
Better:  R-30 cavity blown insulation with contact on all six sides and R-5 insulating sheathing
BEST:  R-30 cavity blown insulation with contact on all six sides, R-10 insulating sheathing, and  airtight sealing

Basement Concrete Walls

Minimum:  8-inch concrete walls with R-10 continuous or R-13 cavity with standard below grade waterproofing system
Better:  8-inch concrete walls with R-13 insulation and minimum R-5 continuous interior or exterior foam insulation with water proofing membrane
BEST:  8-inch concrete walls with R-13 insulation and minimum R-10 continuous interior or exterior foam insulation with hydroscopic water proofing system

Sill-box — Band Joist Area

Minimum:  R-20 cavity insulation or R-13 cavity with R-5 continuous insulation
Better:  R-20 cavity insulation or R-13 cavity with R-5 continuous insulation and airtight sealing (gaskets,caulking, or foams)
BEST:  R-20 spray foam

Stud Walls

Minimum:  2 X 6 Walls with R-20 cavity insulation or 2 X 4 wall with R-13 cavity with R-5 continuous insulation
Better:  2 X 6 Walls with R-20 cavity blown insulation and R-5 insulating sheathing
BEST:  2 X 6 Walls with R-20 cavity blown insulation and R-10 insulating sheathing, with OVE framing, 24” oc, insulated headers, ladder blocking, 2 stud corners

Windows & Glass Doors

Minimum:  U-Factor .35 or less, with proper flashing and slope drainage
Better:  U-Factor .30 or less, Low “E” coating, gas filled, with proper flashing, and slope drainage
BEST:  Triple-pane glass, Low “E” coating, gas filled, with proper flashing, and slope drainage

Ceiling Areas

Minimum:  R-38 blown insulation, with insulation contact – air tight (IC-AT) recessed can lights, sealing all penetrations
Better:  R-45 blown insulation, with insulation contact – air tight (IC-AT) recessed can lights, use of energy trusses, advanced sealing all penetrations from living space into unconditioned areas
BEST:  R-60 blown insulation, with insulation contact – air tight (IC-AT) recessed can lights, use of energy trusses, advanced sealing all penetrations from living space into unconditioned areas

Lighting

Minimum:  High efficiency lighting in at least 50% of the permanently installed light fixtures, CFLs or LEDs
Better:  High efficiency lighting in at least 75% of the permanently installed light fixtures, CFLs or LEDs
BEST:  High efficiency lighting in at least 75% of the permanently installed light fixtures, CFLs or LEDs plus motion sensing CFLs, LEDs, an advanced sealing of any penetrations in envelope used for lighting

HVAC

Minimum:  Furnace with minimum 13 SEER central air conditioner or 8 HSPF heat pump
Better:  16 SEER, 9 HSPF air source heat pump with variable speed air handler or 90% AFUE sealed combustion fossil  furnace with variable speed blower
BEST:  Variable capacity geothermal heat pump
Note: Proper sizing required, Manual J or  equivalent in all  applications.

Ductwork

Minimum:  All ducts, air handlers, filter boxes, and building cavities  used as ducts shall be sealed and if any duct work is outside   of conditioned space, insulated R-8 supply, R-6 for all others, and duct leakage test
Better:  Combination of mastic and UL181 foil tape. Supply and return duct systems should be within the confines of conditioned  space with little or no flex duct
BEST:  All duct work, supply and return hard ducted and sealed. Supply and return duct systems should be within the confines of conditioned space with little or no flex duct, air leakage  tested, sized correctly, and balanced
Note: Proper fabrication/sizing according to Manual D or equivalent in all applications.

Ventilation

Minimum:  Bath fans that meet ASHRAE 62.2
Better:  Exhaust or Supply only ventilation low sone (sound) rating and that meet performance criteria of the bathroom’s required exhaust
BEST:  Source point whole house ventilation with a Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV)
Note: All ventilation must meet ASHRAE 62.2

Water Heaters

Minimum:  Standard storage electric or fossil fuel water heater
Better:  Heat pump or high efficient fossil fuel sealed combustion water heater
BEST:  Desuperheater water heater with geothermal heat pump applications.

Fireplaces

Fireplaces are not recommended but if used consider fireplaces with airtight glass doors and outdoor combustion air or electric fireplace.

Roof / Attic Ventilation

Attic ventilation is required for moisture removal during the winter months and heat removal during the summer months.Proper ventilation sizing requires 1/150th of the square footage of attic area, one-half in high roof and one-half in soffits.

Electrical & Plumbing

Electrical, plumbing, and utility penetrations in exterior walls or through the ceiling should be sealed with airtight construction practices. Recessed lighting fixtures that extend into unconditioned areas include airtight enclosures. Electrical outlets and switches on exterior walls and ceiling light fixtures should be airtight.

Air Tight Testing & Results

Conclusion — Owner/Builder Conversation

 

Save money with energy efficient equipment, appliances and lighting

appliancesHeating and cooling a home accounts for the biggest portion of the typical utility bill. Energy efficient heating and cooling equipment uses less energy to operate and can be more quiet, reduce indoor humidity, and improve the overall comfort of the home. Typically, energy efficient equipment is also more durable and requires less maintenance than standard models.

You can save even more on your monthly utility bill with energy efficient water heaters and ENERGY STAR qualified products such as lighting fixtures, compact fluorescent bulbs or LEDs, ventilation fans and appliances, (such as refrigerators, dishwashers and washing machines). For example, refrigerators may have the same capacity and features, but you could save 10-50 percent on monthly operating costs by purchasing an ENERGY STAR model.

Compare your costs and savings

To compare the operating costs for heating and air conditioning systems, water heating and lighting, use the Home Energy Suite Tool. Select “Save Energy For Your Home,” click “Home Energy Suite” then choose the tool and input your equipment specifications.

To perform a complete home analysis for yourself choose the “Home Energy Calculator” to pinpoint possible energy savings.

Why NPPD supports energy conservation

Energy efficient home construction reduces peak demand for electricity, as well as year-round electricity use. This efficiency delays the need for NPPD to build more power plants, keeping rates low for NPPD customers.