Restoration work following a sediment disaster or volcano disaster may be required in extremely dangerous places. Construction operations in such dangerous places can be executed safely if it can be done using construction equipment that can be operated remotely while observing camera images. Construction using such remote control type construction machinery is called "unmanned construction", and it has been carried out at more than 150 sites in disaster prone Japan. It is said that unmanned construction is generally low efficiency construction so a variety of innovations have been introduced on these construction sites. But until now little has been done to quantitatively verify its construction efficiency and the effectiveness of proposed improvements to the method. This study used test model work proposed by past research to verify the construction efficiency of a remote control type hydraulic excavator. And it offers a proposal to improve efficiency and verified its effectiveness in the same way. The wide remote operator viewing system, with the operator using the cab seat operating device, gave the best remote operating efficiency, although this still took 1.6 times longer to complete the test task than for an operator on the machine.