Window. Safety and thermal insulation - does that work?

In many buildings, both the burglary protection at the windows and the heat protection play an equally important role. Whether both properties can be combined, and where there are limitations, you can read in this post.

Selection of the optimal window

From an energetic point of view, windows should have a U-value of 1.1 W / (m²K) or less. By law, values ​​below 1.3 W / (m²K) according to the new EnEV 2014 are required. When selecting windows, you should already have calculated what value makes sense.

If you equip a low-energy house, you may also have to resort to higher-quality, lower-U windows. In general, passive house windows and low-energy windows assume that the U-value should always be less than 0.8 W / (m²K).

Selection of the optimal safety class

For the resistance classes according to DIN EN 1627, you should in any case analyze your threat profile. For households, class RC 2 is generally recommended on the ground floor, and RC 3 is recommended in special situations.

In the upper floor, if there is no climbing aid and no stand space for the offender, which he can use, you can also limit yourself to windows of safety class RC 2 N or even class RC 1.

Combination of thermal protection and safety

These values ​​can always be combined with plastic windows. If you want higher levels of security or lower U-values, you will probably have to cut corners in some areas. The selection is then not so big.

Increase heat protection and safety even further

By using special window films, you can gain additional protection. The following areas can be covered:

  • Reduction of solar radiation (heating of rooms) by up to 90% through sun protection films and reflective coated films
  • Reduction of U-value by up to 30% due to cold protection foils
  • Upgrading the glass up to safety level P3A (penetration resistance), plus fire retardation and blast resistance

The prices per square meter for films are around 30 - 50 EUR per m², so they can be calculated. Depending on which special function you want in your windows, you can even enhance the performance of the glazing with foils.

For sun protection films, keep in mind that the heat of the sun on the south-facing windows can also be beneficial. It can help you to save considerably on heating costs in the south-facing rooms in winter when the rooms warm up due to the sun's rays. If you are using sunscreen, exclude this effect.

Slides that are used to break-in security are usually already provided with a very effective UV protection. This should also prevent the fading of the film itself. In this case, you should consider which concern you prefer, as you can not glue two sheets on top of each other.

Video Board: How To Insulate Drafty Windows for Winter - Save Hundreds on Heating