This　paper　presents　a　study　of　the　heat　transfer　characteristics　of　new　construction　-　brick　masonry　with　fly　ash　blocks.　Four　forms　of　wall　samples　were　tested　to　evaluate　their　heat　transfer　performance.　Based　on　the　mechanism　of　the　thermal　conductivity　of　clay　bricks,　RCB　(recycled　concrete　bricks)　and　fly　ash　blocks,　an　actual　value　calculation　method　for　determining　the　heat　transfer　coefficient　suitable　for　engineering　design　was　proposed.　By　analyzing　and　comparing　the　experimental　values　with　the　theoretical　and　actual　values　of　the　test　samples,　the　proposed　method　was　proved　to　be　reasonably　correct;　it　used　RCB　instead　of　ordinary　clay　bricks　and　a　composite　wall　with　fly　ash　blocks　showed　an　enhanced　insulation　effect.　New　construction　of　brick　masonry　with　fly　ash　blocks　not　only　is　good　for　the　environment,　but　also　provides　good　thermal　insulation.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.