.

Fig. 1: This mini-building with vacuum insulation integrated within the sandwich structure shows the possible gain in space: if conventional insulation materials were to be used to provide the same level of thermal insulation for this building volume of just 75 m², only 17 m² instead of 25 m² would be usable.
© Dipl.-Ing. Manuela Skorka, Neuried

Fig. 2: Development of heating energy requirements and thermal insulation thicknesses over time.
© RUBIN / Ruhr-Universität Bochum
2 / 17

Improving thermal insulation

A well-insulated building ensures comfortable living conditions and low energy costs. If, however, increasing thermal insulation demands lead to increasingly thick wall structures, not every building developer is amenable to this. This is understandable given that the space required for this is generally very costly. However, the new, high performance vacuum insulation panels offer new prospects.

Since the first German Thermal Insulation Ordinance (WSVO) was introduced in 1977 in response to the oil crisis, the insulation requirements for building envelopes have increased continually. Whereas the 8-cm-thick insulation required for facades by the 1995 amendment to the WSVO was still something unusual for architects and builders, today insulation systems twice as thick are now almost a matter of course in new buildings. And the bar is being raised even further. With the European Union’s aim of introducing an almost zero energy standard for new buildings by 2020, the requirements for thermal insulation are growing with the thickness for the necessary insulation. If such a standard is to be met with conventional thermal insulation materials made of mineral fibre, polystyrene, polyurethane, foam glass or cellulose, this could require thicknesses of up to 40 cm. That in turn requires space, which is usually expensive and is not even always available for refurbishments.

This means that the thermal insulation values required for energy-based reasons are not always so easy to realise in practice. Particularly with the refurbishment of old buildings, retrofitted insulation often leads to geometric problems or unattractive design consequences. For example, the existing roof overhang may not be sufficient for the planned additional thickness or the insulation layer creates deep window openings with unfavourable incident light and unsuitable fields of view – the so-called loophole effect. If the facade directly abuts on the pavement, the retrofitted insulation is usually not allowed to protrude to any great extent. And in the case of internal thermal insulation, the amount of living space lost ought to be kept to a minimum.

High performance insulation materials and components offer space-saving solutions in this respect, which in turn offer new technical and design possibilities. One approach is to provide the insulation with vacuum insulation panels. These flat, evacuated panels were developed in the 1970s for use in cooling and refrigeration equipment and have now been adapted to meet the requirements of the construction industry. With correct planning and careful deployment, they provide very good thermal insulation values with a slim construction.

notepad

BINE subscription

Subscribe to publication

More from BINE

New window frame
BINE Projektinfo 09/2009

Building refurbishment - highly insulative large elements
BINE Projektinfo 04/2008

Vacuum glazing
BINE Projektinfo 01/2008

Vacuum-insulated prefabricated elements
BINE Projektinfo 09/2007

Building refurbishment – Children's day care centre
BINE Projektinfo 10/2006