Installing the additional thermal insulation reqiured for Passive House level of performance. (photo: Schulze Darup). Here, the insulation thickness is 20 cm.

If already insulated, then correctly - also with an old house. Because, properly implemented, the building will not have to be remodeled again until much farther into the future. Adding insulation to the passive house level is economically optimal under the present and future economic conditions. The results of less thermal insulation are already quite expensive - and will only be worse in the future.

Preserving Old substance, while using rennovating to Passive House levels is important as presented byLudwig Rongen at the 10th Annual Passive House Conference in working group V. Also architecture of buildings only in existance a short time so far may not be valued. That is a central topic of interest for the 11. Passive house conference.

Old house reborn- basic rennovation of a terraced house with vacuum insulation to "factor 10" objective by Florian light-blue. Vacuum insulation was a central topic on the 10th Passive house conference.

How does a representative seat for the Suedtiroler national Council for energy develop from a featureless building? Michael tri bus modernized this building in Bozen to the passive house standard.

The measurements below were taken from Nurenberg, Jean-Paul-Platz, one of the first modernizations of old buildings with passive house components. Above is the view of the modernized front.
(Project of Burkhard Schulze Darup)

Results of the consumption measurements from Nurenberg/Jean-Paul-Platz: the heating energy amound determined by PHPP (bar) predicts the energy requirement. The measurements (red squares) verify this: consumption was reduced by nearly a factor 10. (26.9 kWh/(m²a) measured, originally approximately 200 kWh/(m²a)).

A 1960's apartment building became a passive house. André Zaman of the GAG Ludwigshafen presented the experiences in working group 10 of the 10th Passive house conference. The apartment complex under construction was part of the tour during the 9th Passive House conference. The rennovation was finished in 2006. Energy consumption is being systematically monitored in this complex. First results are expected in 2007.

The modernization of the existing building stock is the most important task in the future for the building sector. Presently all of those involved emphasize this, from housing policymakers to builders and building industry. And they are correct, it is important that rennovations be done.

How to do it, however, no-one agrees on. Specifically, the necessary quality level of the long overdue rennovation of the building envelope, windows, and mechanical systems. Still the majority of the owners believe that what is necessary is just to put in a slightly more efficient mechanical system, and maybe stop up some of the leaks in the walls. But even amongst building physicists and HVAC engineers there is an incomprehensible tendency of only encouraging mild rennovations.

• Eberhard Jochem has alread shown, at the 9th Passive house conference, why owners are well advised to correctly compute the economics of efficiency measures. Presently, investments into good energy efficiency are uniquely attractive. Especially, with the very favorable incentives from the KfW Foerderbank.
  
• The often repeated phrase when building new or rennovating is called "if already, because already". Building envelopes are long-lived economic goods; a qualitative improvement omitted today will hurt the owner for many decades. There already several owners, who are annoyed that they spent so much money on their new building or the renovation but only got a moderate increase in energy efficiency.
  
• Mark Zimmermann (EMPA, Duebendorf, Switzerland), showed at the 10th Passive house conference that with energy targets which don't reach the Passive House level, energy sustainablilty will never be attained. Although even the Passive House level is not even good enough, it (and existing Passive House Components) is a good basis for which to build energy sustainability.
  
• Burkhard Schulze Darup discussed the improvements to numerous old buildings in order to meet the objective "factor 10"and contributed important experiences to economics and to strategies for further implementation.

The specialists described above are members of the conference advisal committee. Working groups of the 11th Passive House Conference with the topic of the inventory reorganization will be discussed in detail.

The crucial steps for energy conservation in existing buildings are:

• Very good thermal insulation
• Minimization of Thermal Bridges
• Airtightness
• Balanced Ventilation with heat recovery
• highly efficient Windows
• Innovative mechanical systems

You may notice that these are the exact same elements that worked so effictively with new low energy buildings. In particular the energy-saving components developed for new construction passive houses can be utilized successfully in old buildings - with energy savings of 75% to over 90%.

The energy savings potential of using passive house components is very high: The leftmost graph in the chart above an uninsulated old building with a heating energy consumption around 240 kWh/(m²a). The rightmost graph: When rennovating using only passive house components, heating energy consumption decereases to one tenth of its original value (therefore "factor 10"); this has been proven through implementation. (see the pictures on the left side). If it is only possible to add insulation to the interior, but passive house components are used,it is still possible to reach a 75% reduction in energy conservation. This shows that the best market available Passive House components are viable solutions well into the future.

Here you find to more information for modernization with concrete examples. (German)

Here you find further examples of successful rennovations using passive house components.

Link to the main page of the information about the passive house: Passive house fundamentals.

Link to homepage of the passive house conference:
Passive House Conference.

Go to thepassive house of the institute homepage:

(updated: April 30th 2007 /author Wolfgang Feist Passive House Institute;
unchanged copy permitted - please give reference to the source
thanks to David Stecher for proof reading)