To evaluate the performance of Transparent Honeycomb Insulation (THI), a monitoring program was carried out at Saint Helens (UK). The Northwest and Southeast facades of an existing terraced house were clad with honeycomb transparent insulation. Various heating and energy flow variables were monitored within this Transparently Insulated House (TIH) and in an adjoining Non-insulated House (NIH), which was a mirror image of the TIH. A computer program for the acquisition, storage and processing of data was developed. The accuracy of the monitored parameters was affected by the presence of high frequency electromagnetic waves in the area. This problem was reduced to an acceptable level by close monitoring of the instruments. Data measurement was plagued by excessive noise. Remedial techniques were adapted for dealing with these problems. The results show that in cold climates, THI increases the solar gain to the building and reduces the heat loss from envelop of the building. This provides a strong case for the viability of Transparent Honeycomb Insulation as an effective passive solar technology. © 2005 Taylor & Francis Group, LLC.