The Passive House in Practice

Status

finished

Summary

The development of passive houses has shown that buildings with an energy consumption below 15 kWh/m².a can already be built today economically. Besides energetic and economic criteria building-ecological criteria find increasing consideration. Thus the ecological passive house currently represents the most consistent concept of sustainable building. The spreading of the passive house brings an enormous increase in quality of planning and workmanship as well as the housing comfort with itself and is seen by participants as a new dimension within the domain of building houses. In order to reach a substantial energy-saving building method, it is obvious to further pursue the passive house building concept and lead it also over into the fields of multi- family housing and retrofit building. Watching the statistics of built passive houses in Austria a clear west east downward gradient is noticeable. This is mainly caused by the different basic conditions for low-energy and passive house building, which are given in individual Austrian federal states. Before this background also special obstacles were analyzed in the context of this project. If one refrains from isolated initiatives, then so far a cross-linking of a constantly growing number of activists, comparable with the west of Austria, was missing at the start of the project.

The most important objectives in the project:

• The project aimed to take up the dissemination process of the passive house at this time and to seize and interlace its participants
• to recognize critical moments and obstacles and following to form strategies for further spreading thrust toward eastern Austria
• to create Acceptance for the building concept passive house in the east of Austria
• to develop strategies for the recovery of learning- and diffusion-deficits with the realization of passive houses in the east of Austria.
• to reach a widespread covering of built examples

Results

The passive house represents one of the most consistent concept of sustainable building and brings with consideration of ecologically harmless materials and the use of renewable energy sources an enormous increase of quality in planning and workmanship as well as the housing comfort with itself.

At present a tendency to an all-electrical power supply in the passive house (also for the supply of space heating and warm water) is to notice. In the case of an advancement of the passive house should be worked against this tendency by integration of renewable energy sources. A further option is the advancement of zero-energy concepts. Zero-energy houses actually are cost-intensive solutions, since the focus was on the energy-technical side. On basis of passive houses the cost/use/resources relationship for such solutions improves crucially.

In reference to the comfort ventilation in the passive house, investigations resulted in the fact that a relevant part of the conditions for an optimal function of the ventilation system is based on system planning and its integration into the building concept and not only on the individual technical components. Great importance must be attached also to the clearing-up around prejudices like: "in passive house may not be opened the windows". Opening windows in summer is the most effective method of cooling the building. That applies also to the passive house. The motive to open the windows in order to transport fresh air into the building, steps in the passive house by an automatic dwelling comfort ventilation clearly into the background.

User information for the passive house supports the efficiency of the system, may however be no fundamental condition for the efficiency of the passive house. particularly if this concept should be successfully transfered to the multi-family housing. Therefore in future an appropriate quality assurance will be needed to guarantee, that customers can make sure that one only sells as passive house, which actually corresponds to the quality requirements. The union of activists inside in the interest community IG PASSIV HAUS, which was already founded in Vorarlberg and Upper Austria and is at present in establishment for eastern Austria in the context of this project, set itself the primary goal to create this quality assurance.

The project could offer a platform for about over 50 participants from the ranges building expert, advisor and decision maker, planning, architecture, build-implementing trades, building services, meeting at two workshops, in order to initiate the working group for the passive house in the east of Austria and introduce a common strategy formation.

The term passive house is a technical term, which unfortunately expresses only insufficiently the associated high living quality. It should be described in publications and media by generally understandable and self-describing sub-titles more near, in order to place the qualitative meaning into the foreground.

Also in east Austria a broad target audience can already now be interested in the topic passive house. Over the total duration of the project altogether 1000 persons predominantly from the east and the south of Austria participated in conferences and 350 persons visited in contexts of excursions several passive houses.

Public financial promotions in combination with consulting offers as well as the default of technical minimum standard in the civil engineering regulation are estimated as substantial supporting instruments for the spreading of the passive house. In the meantime the office of the Lower Austrian federal state government decided a new housing promotion, which particularly promotes passive houses. Prescribing an emergency fire-place in the Lower Austrian civil engineering regulation was in the meantime weakened clearly, on proposal it can be done without. The builder-competition for passive house buildings, which was launched in Vienna this year, will cause clear acceleration in demand for the concepts of building passive houses in the next years also in the multi-family housing.

The Experience of living inside a passive house is attached importance for the spreading speed of this innovation. Ideas like e.g. documentation of built examples, collection of destinations for excursions, dwelling on trial in the passive house, internet platforms for the exchange of experience between passive house-residents and interested future users etc. were collected in the project and supplied a further processing. In the context of a present work for a passive house-data base so far about 50 built and/or in planned passive houses in the east of Austria were seized statistically.

The elaboration of examined building details for the planning trade, so that in future in planning and execution time-saving standard solutions can be used, is an urgent task of the next time.

The required high quality of workmanship (large insulation strength, minimized thermal bridges, airtightness of the building) represents a large challenge to the building trade, which must be solved by industry-internal and industry-spreading training course and measures for further education. In this context also the establishment of a educational workmanship center "passive house" and the execution of building company-related measures (training on the job) became lively.

With the realization of multi-family houses in passive house quality at present the risk in the production of the building quality, not yet calculable for the builders, presents itself as special obstacle. Empirical values are present in west Austria already, in east Austria are however still large needs for information for builders, as well as the necessity, legal basic conditions regarding civil engineering regulation, etc. to be created. Concerning the marketing of these dwellings, at present powerful terms and motives, which could induce user inside to prefer straight these dwellings, are missing. For marketing could be used the general trend to wellness and health, high living quality and modernity. Extra costs with the establishment passive houses could be financed by Contracting. A further marketing argument for dwelling companies could be the good building quality - and thus avoiding the occurrence of mould damage and resulting complaints completely. A promoted demo project within the city area as descriptive passive house in the multi-family housing could contribute substantially to the introduction on the market.

Conclusions and recommendations

From view of the project passive house quality is not static but a dynamic concept. High quality of planning and workmanship brings housing comfort primarily up-to-date and durable products to the building user with lowest current energy costs. The solution of technical requirements behind it and the creation of a good price-performance ratio is task of the product manufacturers of passive houses. In this sense demands for the advancement of concepts, components and of passive house architecture are to be made.

Research and development need appear within the following ranges:

Building services and heating systems:

• Standardisation of access openings with air circulations within the building cover, standardisation of sound damming measures in the air pipeline and to the dwelling ventilation equipment.
• Technical measures and recommendations regarding the adherence to a minimum air humidity in winter.
• Development of very low-priced methods to the heat emission over construction units or other radiators. in order to be able to manage a part of the heat emission beyond the heating of supply air.
• Development of concepts to the heat supply of passive house settlements

Architecture, building concepts, building details:

• Development of social and financially adapted zero-energy-houses.
• Development of passive house architecture modules for further lowering of the manufacturing costs.
• Development of ecologically optimized, prefabricated building-insulation facades for the massive construction.
• Solution of thermal bridge- and building details with building-biologically more favorable products (tapes, foils, PU foam...).
• Advancement of the characteristic numbers formation (building ecology, lastingness...) and the simulation instruments.

No other building concept released such dynamics of a total development at the building sector and during the component development in the last decades, like the passive house concept. As particularly salient example is here mentioned the dynamic market for passive-house-suited windows: In few years the loss of energy over window areas was practically halved. Five years ago still only one window product was certified by Passivhausinstitut Darmstadt, at present there are forty certified products. If this trend continues at the building sector, the passive house concept in future will represent a salient size in housing retrofit building. Thus it will substantially affect the building culture and building practice of the next decades.

Contact

Gertraud Grabler-Bauer
AEE Arbeitsgemeinschaft ERNEUERBARE ENERGIE NÖ-Wien
Schönbrunner Straße 253/10, A-1120 Wien
Tel.: +43 (1) 7107523
Fax: +43 (1) 7107523 - 18
E-Mail: arge-ee-noe@magnet.at