Shown in the Video @ 0:52 Achievement "Construction Complete" for 5 GS
When you first establish your home base your will be prompted to build an Infirmary. This is a very important facility and should be build right away! You can build various facilities at your home base at availabel building pads. Building pads are market by a red square. As you stand atop the building pad you will have to press
on your gamepad and select the facility you would like to build.
The achievement will unlock AFTER the construction is completed. The construction times vary depending on the facility but it will definitely take a few minutes to complete.