Enhanced Environmental and Energy Performance Luxury Home
SUMMARY:
This details the nature and costs/benefits to homeowners of added environmental performance enhancements, including indoor air quality and comfort items, and energy and resource efficient features for a luxury home. The home has a total of approximately 6200 square feet of finished, temperature-controlled space on three levels.
Final cost of the home, including all transactions with the builder, owners' vendors, and county and state taxes and fees was $604,487. As detailed below, the initial investment of $20,765 for energy and environmental performance enhancements is expected to be recouped in about 59 - 63 months and produce a 20 year net return in the range of $101,155 - $136,650.
ENVIRONMENTAL PERFORMANCE ITEMS ADDED OR UPGRADED TO HOME:
| ITEMS ADDED OR UPGRADE: | Item Cost |
| Added Energy Efficient Lighting: Ceiling Mounted (8) (Fixtures and Compact Fluorescent Bulbs) | $240 |
| Added Energy Efficient Lighting: Outdoor, Floor Lamps, and Desk Lamps (14) (Compact Fluorescent Bulbs Only) | $280 |
| Upgraded to Energy Efficient "Low-Emissivity" Windows (74) | $3130 |
| Upgraded and Added Exterior and Interior Batt (R-11 to R-15) Wall Insulation | $1600 |
| Upgraded and Added Attic Blown-In (R-30 to R-38) Insulation | $200 |
| Added Tyvek Housewrap and Tyvek Tape | $300 |
| Upgraded to High Efficiency 75 gallon Gas Hot Water Heater | $1200 |
| Added Time- and Temperature-controlled Recirculating Hot Water System | $300 |
| Added Commercial-grade Insulation (R-7) for All Hot Water System Pipes | $150 |
| Upgraded to High Efficiency (10 SEER to 16 SEER) Electric Air Conditioners (2) | $4780 |
| Upgraded to High Efficiency (80% to 96.6% AFUE) Condensing Natural Gas Furnaces (2) | $3980 |
| Added Two Programmable Digital Thermostats (one for each zone)(2) | $530 |
| Added High Efficiency Electronic Air Cleaners (2) | $1720 |
| Upgraded to 25 cu.ft. High Efficiency Top Freezer Refrigerator | $555 |
| Upgraded to High Efficiency Dish Washer | $520 |
| Added High Efficiency Clothes Washer and Dryer | $1195 |
| Added Ceiling Fans with Remote Controls and Built-in Dimmer Lights (4) (Including Pre-wire and Installation) | $1535 |
| Added Energy Efficiency Enhancing Landscaping | $700 |
| Grand total: | $22,915 |
| Rebates from utility companies and manufacturers for high efficiency equipment and lighting: | (-)$2,150 |
| Total net first cost of performance enhancement items (owner's net investment): | $20,765 |
| Total net first cost of performance enhancement items as a percentage of total cost of home: | 3.44% |
| Conservative estimate of average monthly cost savings on utilities (electric, gas, sewer, water) due to performance enhancements (savings based upon cost comparisons with 6 neighbors in the "standard" home model and computer models): | $250 |
| Payback on owner's net investment: | |
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DESCRIPTION OF HOME:
The Home has an approximate 40' x 60' overall footprint size, and is comprised of three levels with an attached garage. During the heating season, the performance enhanced home is maintained at 68o F when occupied in the morning and evening hours, 62o F during sleeping hours, and 55o F when unoccupied. (The house is divided into two separate heating, ventilating, and air conditioning (HVAC) system zones.) Circulating hot water temperature is maintained at 120o F during use hours. Hot water temperature is boosted, only as needed, by the high efficiency dishwasher and clothes dryer to 140o - 180o F in order to meet hygienic requirements. The home includes the following finished, temperature controlled spaces, which - unless otherwise noted - have a ceiling height of 9':
- First floor level: center entry foyer with 19' ceiling height and coat closet; formal living room; formal dining room; study/library; gourmet kitchen with cooking island, breakfast nook, and pantry; open family room with 11' ceiling height and natural stone fireplace; powder room; storage closet; mud room; [unfinished 3-car garage]
- Second floor level: master bedroom suite with 13' peaked ceiling height and separate sitting room with 15' peaked ceiling height, vanity area, three walk-in closets, and full bath with 11' peaked ceiling height and his/her lavatories, stall shower and 6' Jacuzzi; two Jack 'n Jill bedrooms each with walk-in closets and a full bathroom with dual lavatories between; guest bedroom with full bath and walk-in closet; [unfinished attic above]
- Ground floor/walk-out basement level: recreation and game room; aupair/in-law suite with walk- in closet and full bath; storage closet. [unfinished furnace room and hot water heater room, with contiguous large storage areas]
PERFORMANCE AS MEASURED BY UTILITY COSTS:
The average utility costs over a three month period, from November 1, 1997 (when the owners first moved in) through January 31, 1998 were:
- electric service - $1.46 per day or $43.80 per month
- natural gas service (winter rates in effect) - $4.56 per day or $136.80 per month
- water/sewer cost - $0.54 per day or $16.34 per month.
The combined average utility cost per day was $6.56, and the combined average cost per month was $181.13. Based upon the amount of finished square footage (approximately 6200), the combined average utility costs per square foot per month can be calculated:
Electric: $0.0070645 + Gas: $0.0220645 + Water/Sewer: $0.000087 = Combined total: $0.029216
Applying the results to similar homes, assuming that all other factors were equal during the same winter time period, the combined average monthly utility costs for a comparable resource efficient, high performance home with:
1800 square feet of finished space would have been about: $53
2400 square feet of finished space would have been about: $70
3000 square feet of finished space would have been about: $88
3600 square feet of finished space would have been about: $105
4200 square feet of finished space would have been about: $123
4800 square feet of finished space would have been about: $140
5400 square feet of finished space would have been about: $158
6000 square feet of finished space would have been about: $175
(The actual average monthly utility costs for 6200 square feet of finished space was: $181.13)
6600 square feet of finished space would have been about: $193
7200 square feet of finished space would have been about: $210
The operating costs per square foot the resource efficient, high performance home are estimated to be approximately 30% to 40% of the costs experienced by neighboring families with standard features and options. The actual utility costs for any similarly performing home would be expected to vary over time with seasonal temperatures, changes in the rates for utility services, the number and ages of occupants, and the occupants' resource consumption patterns, among other factors.