3. Will a Passive House have a higher cost?
- If all the features, size and accoutrements of a building are the same, its lifetime cost will be lower
- Fixed monthly/annual cost of borrowed capital for improved building features are typically immediately more than offset by the reduction in monthly/annual operating cost (and this improves as purchased energy operating costs inevitably rise)
- The availability of easily distributed energy (in any form) is nearly guaranteed to become more difficult and therefore the cost will inevitably rise
- Replacement and retrofit costs will be reduced by investing a small increment at the initial construction
- Lifetime of a building is notably longer than other products we use
- Through a buildings lifetime, it will not likely have comprehensive renovations more frequently than every several decades – if features of the building envelope has leapfrogged to the future, the renovations may be limited to features other than the building envelope
Building type, Lifetime, (Duration between major renovations)
- Wood frame residential, 40 to 100 years, (30 years)
- Mass (concrete/ICF/masonry/log) frame residential, 80 to 200 years, (30 years)
- Retail/commercial, 20 to 150 years, (10 years)
- Industrial, 15 to 50 years, (25 years)
- Public (transportation, government services, schools, museums, etc), 60 to 250 years, (30 years)
Operations and recurring cost
- More airtight, more compact and smaller systems reduce operating and maintenance cost
- Smaller systems reduce inevitable future capital replacement cost
- Low energy demand permanently reduces purchased energy cost
- Low energy demand make size of optional on site energy harvesting systems smaller (and therefore initial, maintenance and future replacement costs lower)
- Intentional filtered, energy recovering, 100% outdoor, balanced, correct volume ventilation preserve building envelope integrity, reduce occupant health concerns and minimize energy loss due to unintentional/random/varying volume ventilation through a leaky building envelope – better a building breath through its nose than its skin
- Durable building assemblies reduce maintenance time commitment and cost
First day cost
- More than 80% of costs associated with a building construction are not affected. The relative increase in first day costs are primarily for increased insulation, building envelope air tightness measures and high performance (low air leakage, low transmission loss, high or low solar radiation gain glazing) windows and doors. Unlike larger or more complex mechanical systems, these are one-time purchases with virtually no operation, maintenance or replacement cost. High performance windows and doors due to their details of construction are more durable, thus a longer life and therefore can have a lower lifetime cost of ownership.
- Some insulation, doors and windows, and some level of building envelope air tightness is required regardless. Choose wisely in the beginning and the need for replacement later is reduced.
- Mechanical systems are both different and smaller – ventilation and heating/cooling are often separated. Space heating load/demand can become so small that the already required and paid for domestic water heating system can easily satisfy the load/demand. If heating load/demand is small enough, space heating/cooling can be provided through the low volume, but constant 100% outdoor air ventilation system. Because of an airtight and very well insulated building envelope, air temperature is near even/constant wall to wall, floor to ceiling – this may allow point source heating/cooling equipment to perform without the need for space using and initial cost or air duct distribution systems and enclosures.
Even if an air duct distribution system is provided, it will be smaller and thus will require less space for both equipment and distribution.
- Because energy demand is low, if on site renewable energy harvesting systems are considered immediately or in the future, they will be significantly smaller and therefore lower in initial, maintenance and inevitable replacement cost
A quote by a now departed colleague
“I am too poor to buy cheap things”