BPI HHE cheat sheet

A healthy home evaluation is a systematic walkthrough that documents moisture, ventilation, combustion safety, contaminants, pests, and safety hazards room by room before any remediation is recommended.

Standard evaluation sequence: exterior and drainage, roof and attic, basement or crawlspace, mechanical systems, kitchen and baths, living spaces, then occupant interview and records review.

Moisture indicators to record: water staining, efflorescence, bubbling paint, musty odor, rusted fasteners, warped or cupped flooring, and visible mold growth on organic surfaces.

Relative humidity target range for occupied homes is generally 30-50 percent; sustained levels above 60 percent support dust mite and mold amplification.

A moisture meter reading above roughly 16-20 percent wood moisture content indicates elevated moisture; new construction framing is typically targeted below 19 percent.

Combustion safety screening includes backdraft testing of atmospherically vented appliances, spillage checks at the draft hood, and confirmation of a carbon monoxide alarm on each level.

Evaluation documentation should pair each finding with a location, photograph, measurement, and severity rating so that recommendations are traceable and verifiable.

Occupant interview topics: water leaks history, heating fuel type, recent renovations, pesticide use, pets, smoking, and health symptoms with their timing and location patterns.

The four control layers of a building enclosure are water, air, vapor, and thermal; water control has priority because bulk water causes the most damage fastest.

Stack effect: warm indoor air rises and exits high in the building, drawing outdoor air in low; driving pressure increases with height and indoor-outdoor temperature difference.

Air leakage moves far more moisture through assemblies than vapor diffusion; a small hole can transport more water vapor than a large area of permeable material.

The dew point is the temperature at which air reaches saturation; condensation forms on any surface at or below the dew point of adjacent air.

Vapor retarder placement follows climate: in cold climates it goes on the warm-in-winter interior side; in hot-humid climates a vapor retarder on the exterior is generally avoided.

Insulation must be installed in full contact with an air barrier and without gaps; a gap of about 5 percent of an insulated area can reduce effective R-value by roughly half.

Pressure boundaries separate conditioned from unconditioned space; the thermal boundary, air boundary, and pressure boundary should be continuous and aligned.

R-value measures conductive resistance; U-factor is its reciprocal (U = 1/R), and assembly U-factors are summed rather than averaged by area-weighted parallel path methods.

ASHRAE Standard 62.2 sets residential ventilation rates: about 7.5 cfm per occupant plus 0.01 cfm per square foot of conditioned floor area, with a minimum floor value.

Radon is the second leading cause of lung cancer in the United States; the EPA action level is 4 picocuries per liter, and mitigation is recommended at or above that level.

Carbon monoxide alarms should be installed outside sleeping areas and on each level; the EPA 8-hour average ambient limit is 9 ppm and the 1-hour limit is 35 ppm.

PM2.5 refers to particles 2.5 micrometers or smaller, which penetrate deep into the lungs; filtration is rated by MERV, with MERV 13 capturing most fine particles.

Formaldehyde is a common off-gassing VOC from pressed wood products, some foams, and combustion; it is a known human carcinogen and irritant.

Dust mites thrive at relative humidity above 50-60 percent and feed on shed skin; reducing indoor humidity is the primary control measure.

A blower door test measures envelope leakage in cubic feet per minute at 50 pascals; tighter homes require mechanical ventilation to protect indoor air quality.

Environmental tobacco smoke is a mixture of gases and particles; there is no safe level of exposure, and separation by distance or ventilation does not eliminate exposure.

Carbon monoxide binds hemoglobin with roughly 200-250 times the affinity of oxygen, forming carboxyhemoglobin and impairing oxygen delivery to tissues.

Classic CO poisoning symptoms are nonspecific: headache, dizziness, nausea, fatigue, and confusion; symptom relief when leaving the building is a key diagnostic clue.

Fall hazards are addressed with grab bars in baths, stair handrails on both sides, adequate lighting, and removal of trip hazards such as loose rugs and cords.

Scald prevention: set water heater delivery to about 120 degrees Fahrenheit; at 140 degrees a serious scald can occur in seconds.

Lead paint hazards are highest in homes built before 1978; deteriorated paint, friction surfaces, and renovation dust are primary exposure pathways for children.

Asthma triggers in homes include mold, pests and their debris, secondhand smoke, nitrogen dioxide from unvented gas cooking, and fine particulate matter.

Combustion appliances require adequate makeup air; a tightly sealed home with exhaust fans can depressurize and backdraft naturally drafted water heaters and furnaces.

Emergency preparedness for occupants includes working smoke and CO alarms, a posted escape plan, and knowledge of utility shutoff locations.