OPTIMIZE AS A SYSTEM

The following outline details the major design goals and the related issues and elements.

Safety

• Codes  followed.  Exceptions to codes that were allowed by the building department (eg; no poly ground cover in pressurized and heated crawlspace) were carefully reviewed.

• Moisture control measures.
• Vented rain screen.
• Protected walls from exterior moisture sources.
• Prolonged siding life.
• Tight Envelope
• Prevented air transported moisture into walls and attic.
• Unvented attic:
• Enabled by tight envelope and vapor diffusion retarder. Reduces moisture loading in winter.
• Vapor diffusion retarder.
• Used latex paint rated at less than 1 perm by both wet and dry cup test methods.
• Depressurized occupied zone by continuous ventilation system.
•  Provided constant drying of walls in this climate.
• Pressurized "crawlspace"  zone with continuous ventilation system.
• Carefully installed air & vapor retarders protected structural wood.
• Conducted moisture monitoring to verify moisture control.
• Ease of maintenance.
• Very accessible filters
• In HPVAC-80 Heat Pump Heat Recovery Ventilator.
• In Earth Tube Intake Filter Box.
• Separate mechanical room in conditioned space for maintenance access.
• Pressure-difference manometers, fan speed controls

• Warm floors.

 
• Zonal temperature control (heating season only).

 
• High R glazing.

 
• Tight envelope.

 
• Acoustically quiet because of tight envelope, R45 walls, triple glazing, etc.

 
• Conditioned fresh air continuously ducted to most rooms.

 
• Acoustically isolated bedroom and bathrooms.

• Sense of volume, space, connection to outdoors.
• Elevated ceiling and balcony hallway over living room.
• Large windows.
• Standard tempered patio door glazing: inexpensive, replaceable.
• Ganged together & butt glazed to avoid visual obstruction.
• Clean, simple, uncluttered interior: sheetrock and natural wood finishes.

 
• Deep window sills with sheetrock wrap into window recesses.
• Excellent light diffusion: "halo" effect.
• Sills provide very handy shelves for artwork & other artifacts.
• Preference for "real" wood reveal rather than more costly "cosmetic" wood.
• Structural glu-lambs left exposed.
• Glu-lambs sealed with clear finish to enhance natural beauty (rather than "wrapped in oak").
• Recycled vertical grain fir cabinets less expensive and more esthetically pleasing.
• Wrap-around porch.
• No solar penalty since tall spruce trees to south already obscured glazing.
• Covered porch at main floor level for easy access and daily use.

• Owner has allergies.
• Make-up air via earth tubes filtered to remove most pollens and wood smoke particles.
• Make-up via depressurized envelope filtered by insulation (dynamic wall).
• Continuous ventilation capable of adjustment over range of air change rates.
• Owner can adjust particulate removal rate.
• Radon.
• Tight envelope enables mechanically induced pressure-difference control.
• Climate impact on air change is negligible.
• Continuous mechanical ventilation creates required pressure-differences.
• Normal operation of continuous mechanical ventilation system has been adequate.
• "Crawlspace" is really a pressurized exhaust air plenum.
• Plenum has no vents and has airtight separation with respect to occupied zone and outside.
• Plenum is pressurized to prevent soil gas entry.
• Air in plenum is continuously flushed to outside.
• Formaldehyde.
• All structural paneling has phenolic resins.
• Linoleum underlayment is low emitting: HUD rated material.
• Cabinets are mostly fir rather than particleboard.
• No combustion appliances.

 
• No lead-based paints.

 
• Tight envelope isolates garage, solvents, cleansers etc.

 
• Continuous ventilation capable of adjustment over range of air change rates.
• Owners can respond to occupant loads and other occasional pollutant loads.
• Owners can respond to seasonal and other changes in pressure-differences by adjusting fan speed controls.

• Maximized available on-site solar potentials.

 
• Addressed conduction with High R values.

 
• Addressed convection with tight envelope.

 
• Heat pump heat recovery ventilation provided 50% annual heat load.

 
• Zonal electric resistance provided other 50% & allowed zonal "comfort/efficiency tuning."

• Owners' esthetic taste desired simplicity and function, and disliked extravagance.

 
• Owner's provided significant labor.

 
• The building's estimated cost  is between $45 and $50 per square foot.