Dear Steve, We have been in our house for 5 years. Our house is on a farm approximately 29 kms from Cooma NSW. We are at an altitude of 800 metres. We experience snow at least once or twice a year. Our temperature extremes are -12 degrees centigrade in the winter and 38 degrees centigrade in the summer. the exterior of our house is not sealed with a sealer but we did seal the southern side because it faces our most constant wind and rain exposure. There is absolutely no sign of any deterioration of the blocks. The house is generally 10 degrees warmer in the winter and 10 degrees cooler in the summer than the outside temperatures (about 18 to 22 degrees constant).. The house is heated by a free standing combustion wood fire. We have not finished installing insulating Batts in the ceiling but the roof does have the foil insulation inside. The slab is not insulated and the windows are not double glazed. We have regular aluminium windows. On a very cold night we do experience some condensation on the windows but certainly NOT on the blocks. We use no cooling in the summer. We highly recommend the timbercrete blocks to anyone who wants a strong, economical, thermally sound and aesthetically beautiful building material.We would build again using the blocks tomorrow! We had absolutely no queries from our the Cooma- Monaro Council when we sought our building application in 1999.The engineering certificate supplied by Peter Collier more than satisfied the council requirements. We would be happy to supply any more information that might support you in this venture and we wish you well, regards, Colin and Jan Dear Mr Steve Watts Thank you for your email regarding the use of the timbercrete product for residential dwellings in the Blue Mountains City Council area. There have been a number of dwellings constructed using the timbercrete block system in the Blue Mountains Council area. The timbercrete block work has a high standard of finish at the time of the final inspection on the dwelling and there has been no issues relating to the performance of the product in the residential area. The technical details supplied by Timbercrete Australia through tests by the CSIRO have satisfied Council officers that the product is suitable for use in the residential market. I trust the above information addresses your enquiry, however should you require clarification please contact me accordingly. Regards Rodney Bles Senior Environmental Health and Building Surveyor Environmental and Customer Services Group Blue Mountains City Council