As only the foundations and the lowest parts of the buildings have been found the rest of the building is an educated guess at the best. The layout of the building is an adaption to the voxel grid of Minetest and as thus is not absolutely true to the archaeological findings.
And indeed all this uncertainty and adaption is the basic idea to this map. In the overview map you can see the plan of the building repeated five times around my reconstruction. You are invited to build your own version based on one of those plans. This could also be used as a multiplayer map with different teams using a plan each. For example as classroom project.
Consider using different materials, different wall types and styles (e.g. the top parts could have been timber framed) or different heights. The three rooms to the left of the main building where oriented towards the inner courtyard in the older reconstructions. More recent versions have interpreted them as open to the street and containing little shops. The gate to the courtyard on the right is probably wrong and a mistake of mine, just as the little office and restroom I put into the building on the right. Rather some toilets may have been located here among other things. I have not rebuilt the hypocaustic heating system as that would have needed an extra mod. Similarly the draining system for the used water has not been reconstructed.
So study some ancient roman architecture and try yourself at the art of reconstructing a long gone building or build your very own fantasy freestyle version of a roman style public bath.
Visit the homepage of the Museum or search for thermenmuseum heerlen to see plans, fotos and other reconstructions.