Week 10
Pre-Session Reflection:

Individual reflections on the article "Passive House Standards Make Net-Zero Easier" by Steve Hansen

Passive House will aims to reduce a building’s energy consumption by up to 90% where the rest of the energy required is to be provided by renewable energy sources, thereby effectively resulting in a zero-carbon building.

Recently, in 2015 Passive House launched two new certification standards, namely Passive House Plus and Passive House Premium. These new standards have higher performance benchmarks with lower energy consumption and energy generation (on site and off-site).

Typical Passive House strategies that reduce energy consumption include:

• high level of insulation
• triple glazing
• airtight envelope with minimal thermal bridging
• heat recovery ventilation system
• solar generation through PV system (energy surplus fed into grid)
• ground source heat pump for hot water and heating demands

Post Session Reflections:

Personal Reflections on "Passivhaus - Unravelling the Numbers" by Clare Parry 

The author points out that there are several misconceptions surrounding the Passive House System. The include:

• Passive House is only concerned with energy savings. This is untrue as the standard also covers thermal comfort and considers the comfort of occupants.
• Recently introduced Passivhaus certifications – Plus and Premium – projects now need to get the regional primary energy factor approved before certification. Thus, calculations are more accurate, making the standard locally relevant. Furthermore, the standard aims to achieve decarbonisation of the local electricity grid.
• Passive House considers the balance between increased capital investments vs. real energy savings (e.g. HVAC systems, etc. that are required for meeting certain criteria). It is an as-built standard.
• another misconception is that Passive House cost more to build. Data from Europe indicates Passivhaus can be achieved for 3-8% more than conventional buildings. However, it can be cost neutral and sometimes less expensive you can reduce the size of HVAC systems and potentially also give plant space back as occupiable area. Long-term there will be economic savings through reduced energy usage that will offset any additional construction costs compared to conventional buildings. Passive House also have a certain value and prestige that may appeal to tenants and results in lower vacancy rates and potentially higher rents due to more desirable space.
• passive house is also up to date and following market trends. There is now a sketchup plugin available for the passive house analysis. Additionally, the standard also progressed to better suit retrofit projects with EnerPHit. Passivhaus Plus and Premium certifications were recently introduced to account for on-site energy production and net positive energy buildings. Overall, passive house covers a wide typology of building types.
• passive house is also suitable for warmer climates that are different from those in Germany. This is because the passive house was developed in the basis of building physics and the fundamentals of heat transfer which are universal regardless of climate.