Heat loss and thermal bridging

As the weather turns cold, we start to see things with thermal imaging cameras that during the summer are not so obvious.  These images show why we use these cameras.  This is a conservatory - oak timber framed, and the eaves detailing is not good enough to prevent cold air from entering under the eaves, and getting into the house.  Clearly, air tightness here is a problem, and the contractor has been brought back to address this, probably by adding more insulation at the eaves, and making sure that joints are caulked with oakum to prevent air leaking round the timber beam joints.