On re-reading their brochure they look pretty flakey actually:

"In terms of health; the house also incorporates, “XUND-E”, a unique protective shielding concept, which dramatically reduces the amount of electromagnetic radiation penetrating the home which does not interfere with electronics such as cordless phones and baby monitors. The XUND-E plate, which has been patented by Baufritz, comprises thin layers of carbon with a layer of natural gypsum board, which is then applied to the walls and roofs and then earthed. This layer cuts out up to 99% of all high-frequency radiation and low frequency static emissions cause by alternating currents flowing through high tension cables. Various s...

On re-reading their brochure they look pretty flakey actually:

"In terms of health; the house also incorporates, “XUND-E”, a unique protective shielding concept, which dramatically reduces the amount of electromagnetic radiation penetrating the home which does not interfere with electronics such as cordless phones and baby monitors. The XUND-E plate, which has been patented by Baufritz, comprises thin layers of carbon with a layer of natural gypsum board, which is then applied to the walls and roofs and then earthed. This layer cuts out up to 99% of all high-frequency radiation and low frequency static emissions cause by alternating currents flowing through high tension cables. Various studies throughout Europe and the world prove a definitive relation between the increase of cancer and neurological diseases and high frequency radiation and the protection from this harmful influence can also enhance sleep quality for those living in the house. This innovative product is fitted as standard to all Baufritz homes. This innovative product is fitted as standard to all Baufritz homes. "