by John F Robbins  CEM / CSDP

Below is the evaluation format I use for existing and new homes.  If being designed, I can use analysis software to estimate heating and cooling energy, then interview future occupants to estimate other energy.  For new designs, it's good to know energy use in a prior house so new house performance can be compared.  For existing and new homes, I can also help to track year-to-year energy use.

I. Record & Assess Current Annual Usage & Cost

.....Compile at least 1 calendar year of usage and cost for conventional energies:

.....Natural Gas (Ngas)
.....Liquid Propane (LPG)

.....How does your usage & cost compare with local & regional norms: per-sf of floor area, per-person?

.....How does your energy-related pollution compare?  

.....TO MAKE THIS EASIER, if you live in the Midwest USA (Ohio, KY, Indiana, etc), participate in my no-cost Home Energy Survey!

.....Or use the following tables to estimate energy contents and CO2 emissions for common conventional energies:

Energy Type Btu Content
Electricity 3414 per kilowatt-hour (kWh)
Gasoline 125,260 per gallon
Heating Oil 139,000 per gallon
Kerosene 137,000 per gallon
Liquid Propane 91,600 per gallon
Natural Gas 102,900 per hundred cubic feet (CCF)
Wood 18,750,000 per mini-cord (3/4 of a full cord)

Energy Type CO2 Emissions
Electricity 2.1 pounds per kWh (based on Gtr. Cincinnati generation fuels mix)
Gasoline 22 pounds per gallon
Heating Oil     26.4 pounds per gallon
Kerosene 21.5 pounds per gallon
Liquid Propane 12.5 pounds per gallon
Natural Gas 12.1 pounds per CCF
Wood n/a

.....If your usage or pollution is higher than local norms, you should feel more urgency to lower your usage or seek cleaner energy.

.....If your usage or pollution is average, you should feel less urgency to lower your usage or seek cleaner energy than if you are a guzzler.  But even average users can usually find significantly large cuts.  If your usage or pollution is far below average, then maybe you don't need to cut further.  If you want to know what's currently "best" among local households for energy and pollution performance, check my recommendations at "Outcomes to Aim For", or read my recent survey reports which document how low energy use and CO2 are among leading households.  

II. State Your Reasons, Goals & Commitments Clearly

.....Save how much annual energy or cost?
.....Cut how much capacity or cost for new energy supplies or equipment?
.....Save how much energy or cost in the future?
.....Achieve what payback or return on investment?
.....Reduce or cut need for future additional energy or energy equipment?
.....Manage resources better?
.....Reduce uncertainties?
.....Improve reliability and/or supply adequacies?
.....Improve individual control of this responsibility?

.....Reduce how much pollution?
.....Reduce how much responsibility for pollution?
.....Preservation or restoration?

Health & Safety

Self-reliance & Security

Ethics, Preferences & Politics

Other Reasons & Goals?

The following questions and comments
describe many different opportunities
to lower energy usage, cost and pollution!

III. Optimize Site & Landscape
.....How well does building geometry access winter sun to the southeast, south and southwest?
.....How is the building amply shaded in summer to the east and west?
.....Are vents and least airtight assemblies in living spaces sheltered from winter winds?
.....Do overall design and individual rooms have layouts for good natural ventilation?
.....Are high-moisture room windows and exhaust vents directed downwind?
.....Are there south-facing angled roofs or other surfaces for solar collectors now or in the future?
.....Are perimeter grades, pavements and building surfaces sloped & positioned for natural drainage?
.....Is rainwater collected, stored or used?
.....Are toxics or wastes stored or processed optimally?
.....How Is recycling of common disposables & compostables accomplished?
.....Is a structure being built, remodeled and improved with minimal negative construction impacts?
.....Is a natural site being restored to health, or a healthy ecosystem protected?
.....Is efficient transportation available to most-traveled locations (work, stores, schools, etc.)?
.....Is firewood from local deadwood or waste?
.....Are there limitations on how this site or structure can be modified?
.....Do laws, local associations or programs offer special opportunities or protections for this site or its structures?

IV. Maximize Insulation & Airtightness
(see also "Common Home Energy Specs")

Opaque Assemblies (good general targets)
.....Ceilings (R-38 to 60) and airtight
.....Attic-access doors (R-10 to 30) and weather-stripped
.....Wall & floor edge (R-15 to 30) and airtight
.....Near-grade slab (R-10-20) and airtight
.....Basement wall (R-10 to 20) and airtight at top
.....Basement slabedge (R-5 to 10)
.....Subslab (R-5 to 10)

.....Total unit R - 3 or higher
.....Air leakage no higher than 0.10 cfm/sf @ 25mph
.....Less solar-transmittant glass or shading for summer sun
.....No all-metal frames
.....Full screens w/ dbl-hungs operable top-down
.....Able to be ‘latched’ tight
.....Weather-stripping verified in good shape

.....If glazed, at least double pane w/ low-E
.....If opaque, either solid wood or foam-core
.....Air leakage no higher than 0.10 cfm/sf @ 25mph
.....Weather-stripping verified in good shape
.....Storm Door?

V. Is HVAC system Efficient & Adequate?

Are the systems sized and installed correctly?
.....heating sized to hold 65F when it's the lowest probable temperature outside? more than 20 Btuh/sf should be adequate for well insulated airtight home?
.....combustion supplied with adequate outside air?
.....combustion chambers sealed from living space?
.....airtight ductwork, both supply and return?
.....ducts inside conditioned space or well insulated if outside it?
.....AC system sized conservatively, never oversized?
.....insulated water heater and hot water pipes?

Are heaters most efficient and least polluting?
.....efficient furnace combustion (90% min. AFUE)?
.....heatpump with HSPF 8 minimum?
.....pellet stoves & fireplaces with firebox airtight to living space?
.....most efficient (70% or higher) wood fires with lowest emissions (< 3 grams/hr)?

Are cooling systems most efficient and least environmental impact?
.....SEER 12 or 13 minimum?
.....outside units not located in full afternoon sun?
.....reasonably short refrigerant lines?
.....refrigerant line insulation in good shape?
.....outdoor unit access to plenty of free airflow?
.....non-CFC refrigerant?
.....user-adjustable room fans to increase local air movement as desired to allow higher t-stat setting?

Are heating & cooling systems operated efficiently and appropriately?
.....turned down or off when not needed for long times?
.....timer thermostat?
.....electric water heater timer?
.....use of manual switches?

VI. Take Advantage of Solar

Is there a sunspace or greenhouse attached to the house with south-facing glass?
.....Are there winter vent paths to and from the solar-heated areas of the house?
.....Does it have summer ventilation separate from conditioned spaces?

Do most windows face south (i.e., 8-12% of the conditioned floor area)?

Do interior design and window treatments allow good daylighting?

Are summer sunbeams adequately shaded from entering windows and doors?
.....special building geometry?
.....low solar heat-transmitting glazings to east and west? and shades managed optimally?
.....avoidance of skylights, especially facing east, south or west?
.....trees, shrubs and vines to shade summer sun around common structures and activities?

Active & PV
.....Solar panels to heat water?
.....Solar panels to heat air during winter?
.....Blowers or pumps moving solar heated fluids to remote locations or to thermal storage?
.....Solar panels to produce electricity or charge small batteries?
.....Solar energy used for cooking or food drying?

VII. Improve Indoor Air Quality

Are low pollution materials used in construction and operation? or few exposed particle boards? or few carpeted floors? and low VOC paints and finishes? exposed loose insulation?
.....measures to control and minimize dust & pet dander?

Are paints and finishes applied when windows can be open for maximum ventilation?
.....can living spaces be "baked" before occupancy to permit accelerated offgassing?

Are envelope surfaces typically warmer than dewpoint to prevent condensation when air is humid? indoor concrete directly on the ground?
.....foam exterior wall sheaths over wood or metal framing?
.....high-R windows without metal framing?

Is there ample air exhaust, fresh air supplies, air filtering and dehumidification?
.....exhaust fans?
.....air-to-air heat exchanger?
.....air filters?
.....efficient vacuum cleaning?

Do occupants know to shut windows when outdoor dewpoint exceeds 65-70F?

Are smoking & use of toxics done inside only with maximum ventilation?

VIII. Use Most-Efficient Appliances, Equipment & Devices

Hot water
.....minimized hot water use, water conserving showerheads and faucets?
.....well-insulated pipes and tank with least exterior surface areas?
.....shortest runs from tank to points of most use? assist if electric resistance water heater?

Refrigerators & Freezers
.....smallest acceptable size with least energy-using special features? refrigerator door style, chest-type freezers?
....."most efficient" according to ACEEE "Consumer Guide to Home Energy Savings" (
.....not exposed to direct sun or next to ovens?
.....lids and doors close tightly?

.....front-loading washers (horizontal axis) or other low-water-using type?
.....cold or coolest wash & rinse?
.....outdoor hang-drying when above 50F and not too humid, indoor hang-drying with ventilation?
.....electric dryer only when no other choice?

.....machine used to wash only full loads, cold rinse, air dry without heat?
.....hand-wash small loads, cold rinse, air dry?

.....fluorescent and LED electric lamps?
.....dimmer general lighting, brighter task lights close to light-demanding tasks?
.....outdoor lamps lowest-watt, aimed down, shielded from direct view and kept off during daylight?

Computers & Small Electronics
.....notebooks models instead of desktop models, flat screens instead of tube monitors?
.....computers, TVs, entertainment centers, etc., positively "off" when not in active use for one or more hours? electric as possible for landscape lights, pumps, small battery chargers, calculators, wrist watches?

John F Robbins CEM
3519 Moffett Rd
Morning View, KY USA

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