Near the northern corner of the fort, archaeologists have uncovered the telltale signature of a small mud-and-stud building. Many buildings in the fort that exhibited this style of architecture have already been found, but this is the first time the trenches dug between the post holes for securing the studs have been clearly visible. In past excavations within the fort, only the posthole patterns from these buildings remained. This was largely due to the loss of soil from plowing and/ or the construction of the Confederate earthwork, Fort Pocahontas. The survival of the trenches with this building can be attributed to its location under the Civil War fort, meaning no soil was stripped away here but rather it was added to this location to build up the fort’s earthwork mounds. Another likely reason the building appears to have survived so well was the presence of a large brick chimney base from a later 17th-century building, which was located in the middle of the mud-and-stud building. The presence of this brickwork appears to have saved the earlier building from heavy plowing as the farmers in the 18th and 19th centuries simply lifted their plow blades to avoid hitting the bricks.
The building is 12 feet wide by at least 20 feet long. The function of the building is not known, but it is located within just a few feet of several archaeological features relating to iron smelting from the first years of James Fort. In addition, it is less than 10 feet from the cellar that served as a blacksmith shop. With the proximity to these features there is speculation that this small structure may have served as a workshop relating to metallurgical activities. At this point another theory is that this building may have served as the fort’s corps de garde. The documents clearly state that somewhere in the interior of the fort was a "corps du guard" or "guardhouse," which would have included arms and armor as well as soldiers at the ready for duty. According to William Strachey, "In the middest [of the fort] is . . . a corps du guard. . . ." Interestingly, when the nearby cellar, that had served as a blacksmith operation and subsequently a bakery, was abandoned, it was filled with dozens of sword parts, a close-helmet, and numerous other pieces of armor. Could this have been discarded armor from the nearby "corps du guard"?