English

Implementing the EU-directive 2002/91/EF in Danish legislation led to regulations in the Danish Building Regulations on air tightness in buildings set out by the Danish Enterprise and Construction Authority, a department of the Danish Ministry of Economics and Business Affairs. From 2006 air leakage through the building envelope exceeding 1.5 l/s pr. m heated floor area at 50 Pa was not permitted in new buildings. In addition Local Authorities have obtained legal rights to withdraw the Planning Permission if the building exceeds the limited value.

This paper will present current procedures on the main amendments in the forthcoming Energieeinsparverordnung (German energy-saving ordinance) for 2009, as they stood at the publication deadline of 30 April 2008, along with the main changes to certification procedures in residential and non-residential construction. The new series of standards, DIN V 18599, that were applied only to non-residential constructions in EnEV 2007, has now been proposed as an alternative procedure for residential construction.

Thermography is often used to locate leaks in connection with an airtightness check. In this context it is important to know under what conditions the inspection system can recognise defects to a degree of certainty and reproducibility.Applications of leak location in checking airtightness use the excitation of the building envelope, in that energy is drawn through the building envelope at defective points, cooling the building down. In this respect, applications of active thermography would be appropriate.

The Blower Door procedure has shown itself to be a very effective instrument for analysing and quantifying the various components of the total problem for complex ventilation issues.

In all areas, concern is growing on the rising numbers of mould occurrences in residential buildings. A new survey has provided statistically reliable quantitative German data for the first time, according to which almost every tenth apartment is affected by mould. For 5.8% (around 2.2 million apartments) there was a connection between ventilation and mould. Furthermore, a significant correlation was identified between damp in the apartment and residents susceptibility to illnesses such as asthmatic problems and allergies but also to common colds.

Conventional techniques for the measurement of adventitious leakage of building envelopes are based on steady pressurisation at high pressures (e.g. 50 Pa) that are not normally encountered with natural or mechanical ventilation. It is the leakage at low pressures (e.g. 4 Pa) that is of interest and it is shown that the conventional technique leads to large uncertainty in the low-pressure leakage. Ideally a pressurisation of 4 Pa should be used, but with the conventional technique the uncertainty due to wind effects is unacceptably large.

A thermally conductive building envelope must be constructed to be permanently airtight - this has been compulsory according to German building regulations since 1 Jan. 1995. That 6 Para. 1 of the current Energy Saving Regulations, in force since 1 Oct. 2007, nevertheless requires construction of a airtight building envelope not only according to the current 'state of the technology' but to the 'generally recognised rules of the technology' is barely comprehensible, as rules of technology relevant to airtightness, that could be valid as 'generally recognised', are hardly evident.

Although there have been built about 20 sports halls with passive house standards by now, where the principles of residential houses and first experiences of built sports hall projects were used, but concerning the principles, there are still considerable gaps in the knowledge. In this article, questions concerning ventilation, heating and air tightness of highly efficient sports halls will be discussed. Unlike other types of buildings, sports halls possess a considerable higher ceiling height, which can lead at heat drop in conventional halls to considerable temperature layering.

So far, the ideal-tight typical cross section is usually considered at the evaluation of constructions with the help of hygrothermal simulation. Usually always appearing additional humidification at lightweight construction elements, caused by convection, is not considered so that impermeable constructions seem, contrary to practice, more favourable than those that are more vapour-permeable.