Day 2 begins notably colder. After a pleasant but bitter stroll to Frankfurt Messe we sit down to a plenary session on the topic of “The EU Path to 2020”. Since 2002, there has been energy efficiency legislation in place, with current requirements including minimum energy performance of certain building types, Energy Performance Certificates in every EU country for sale of real estate and inspection of the efficiency of heating and cooling plant.

A note of something clarified: nZEB does not refer to net zero energy buildings. Net zero energy buildings are not necessarily efficient buildings, this term simply refers to the offsetting of a building’s energy. The supposition of energy efficiency is not made. However, NEARLY zero energy buildings refers to the building in what we would consider its “raw” state; that is, the building is efficient as is, and is nearly zero energy. The inclusion of renewables would then serve to make the building zero energy. The term ‘net’ makes no reference to efficiency, merely arithmetic. Just something that was clarified for me today and shed light on a previously misunderstood concept. My ‘ahhhhh…’ moment for the day.

One element of the EU Directive that I managed to catch (through a strong Scottish accent) was that by the end of 2018 all new public buildings must be nZEBs. If only we had these targets down under! (Note: it took 15 minutes for me to figure out that the accent was Scottish and not some form of German. I’d like to blame the jetlag, but I’ve been here a week now). For more info on the EU Directive on energy efficiency see

“Failure has a significant role in successful design”

An interesting chat follows, in a typically and distinctly American fashion, from James Scott Brew. Formerly of the Rocky Mountain Institute, Brew begins by noting the readiness of the engineering faculty to discuss our failures. The Passive House community is particularly fond of this, proving and disproving certain concepts and approaches in a readily offhand manner.

Interesting notes follow on the Empire State Building renovations:

  • Most of the basic measures undertaken to improve energy efficiency through fabric upgrades were not considered in the first draft of the upgrade proposal, e.g. windows;
  • Implemented efficiency improvements took just over 2 years to pay back;
  • These measures eliminated the requirement for a massive chiller upgrade, one of the initial “essential” proposals. This chiller upgrade was to cost US$17m. A powerful message on the influence of optimising building fabric!

Applying Passive House in hot and humid climates

Jessica Grove-Smith, of the PassivHaus Institut, outlined the calculation methods pertaining to projects in hot and humid climates using the PHPP. It was quite a relief to see that these methods aligned very closely with our own. Phew! Over 12 months work validated in the short space of one hour. The new PHPP tool, to be released in “summer 2013”, will contain a more accurate calculations methodology for hot and humid climates, taking into account with much more detail both the latent and sensible loads. Extensive theoretical work, coupled with monitoring of actual projects, has led to the validation of the advancement of the PHPP in these climates.

New outputs include the breakdown of latent and sensible loads, rather than a total load, and the identification of the peak loads.

We look forward to the release of PHPP 2013 (version 8), with bated breath. Well, maybe not that much, but it will be a very useful design and validation tool for Passive House projects.

A summary of the highlights of the conference sessions will follow tomorrow!