Passive House Considerations

Definition Considerations Cost Appearance How To North American Map

2. What does Passive House consider?

Inevitable future costs

  • Routine/recurring maintenance will be reduced
  • Capital replacement for things that wear out will be reduced
  • Energy use will be dramatically reduced (55 to 65% overall, 80 to 90% for space heating/cooling)
  • Reduction in monthly/annual operating costs will be immediate and permanent and will, at least in part, offset initial cost of improved building features.
  • If cost of improved building features are financed monthly or annually, they are offset each month/year by operating cost reduction for term of financing. At end of financing term, operating cost reduction is retained.

Human motivators

  • Long term financial gain (lowest lifetime cost)
  • Recurring expense reduction (lowest operating cost)
  • Improved health (most healthy/clean/hygenic air environment)
  • Increased comfort (most even/consistent temperatures wall to wall, floor to ceiling, adjacent to glazing)
  • Reduced time maintaining own environment (durable materials and compact systems)
  • Increased time for enjoyment (less maintenance, more fun)
  • Feeling positive about reduced impact on environment and others (global conscience)
  • Future energy use reduction retrofit capital costs are virtually eliminated, leap frog to the future
  • Other resource (i.e. water, peoples time, etc.) needs are reduced

Due to very low energy needs

  • Many options for fuel source when fuel need is small to tiny
  • May produce or harvest all energy on site with small systems – therefore the initial and future replacement capital costs are lower and operation and maintenance costs are lower
  • May well be comfortable/usable with no energy input at all, protecting occupants from utility power outages

Lowest Monthly, Annual and Lifetime costs (in lieu of 1st day purchase cost)

  • Revenue producing potential vs. expense limiting need
  • Routine/recurring maintenance and intensity
  • Systems capital replacement frequency
  • Occupancy/use pattern (density, frequency, duration)
  • Free heat gain (internal [occupants, lighting, equipment] and solar radiation) potential
  • Free cooling and heat prevention (strategic shading, natural ventilation [stack, cross, nighttime])
  • Energy loss (transmission and ventilation) reduction
  • Material durability (minimize hygrothermal related moisture accumulation)
  • Existence and/or length of finance/credit maintenance

Technical concern for hygrothermal activity

  • Heat always moves to less heat until balanced
  • Humidity always moves to a drier environment until balanced
  • Humidity that reaches dew point temperature/pressure will condense into water
  • Air and moisture vapor (humidity) will move through the smallest of openings
  • Water will not move through the smallest of openings, therefore may be trapped
  • Elimination of uncontrolled air leakage will dramatically reduce condensation potential
  • Elimination of uncontrolled air leakage will dramatically reduce undesired weather penetration
  • Elimination of uncontrolled air leakage will dramatically reduce undesired and unnecessary space conditioning energy
  • Undesired humidity can be removed by passing air through an environment below dew point (condensing) temperature or above saturation (evaporation) temperature

Definition | Considerations | Cost | Appearance | How To | North American Map

Passive House Considerations