**4.5 Progression on the working performance of the opaque house**

The results of the research on the opaque house, as NEDO's project, carried out at the main site of the proving test; Ashoro, were described mostly. However, in the parallel activity, at the sub-site; Asahikawa, Hokkaido Forest Product Research Institute (HFPRI), which is a member of our project team, in order to grade up the performance of the opaque house, a patient examination has to be continued for more efficient usage, after the expiry of the national project. A technical advantage was found out for the laminar larch lumber, to produce high quality materials with less moisture distribution and less exude of resin than former (Kanayama, K., et al., Nov., 2010), (Koga, S., et al., Oct. 2008). Moreover, HFPRI is examining now how to dry not only lamina lumber but also large square sectional lumber with high quality as short as possible utilizing solar radiation only, without any auxiliary heat. Good result is expected.
