[NERATIUS libro sexto membranarum. ] §39.2.47.prQuod conclaue binarum aedium dominus ex aliis aedibus in aliarum usum conuertit, non solum si contignatio, qua id sustinebitur, orietur ex parte earum aedium, in quarum usum conuersum erit, earum fiet, sed etiam si transuersa contignatio tota in aliarum aedium parietibus sedebit.
When the owner of two buildings converts a room from one building to the use of the other, that room becomes the property of the building to whose use it has been converted, not only if the timbering by which it is supported projects from the side of that building to whose use it has been converted, but even if the entire transverse timbering rests upon the walls of the other building.
sed et Labeo in libris posteriorum scribit binarum aedium dominum utrisque porticum superposuisse inque eam aditu ex alteris aedibus dato alteras aedes seruitute oneris porticus seruandae imposita uendidisse: totam porticum earum aedium esse, quas retinuisset, cum per longitudinem utriusque domus extensa esset transuersae contignationi, quae ab utraque parte parietibus domus, quae uenisset, sustineretur.
Moreover, Labeo writes in his posthumous books that the owner of two buildings built a portico over both of them, and, having granted access to it from one of the buildings, sold the other building under the condition of an easement of the burden of maintaining the portico; he states that the entire portico belongs to the building which the owner had retained, since it extended along the length of both houses upon transverse timbering which was supported on both sides by the walls of the house that had been sold.
nec tamen consequens est, ut superior pars aedificii, quae nulli coniuncta sit neque aditum aliunde habeat, alterius sit, quam cuius est id cui superposita est.
Nevertheless, it does not follow that the upper part of a building, which is connected to nothing else and has no access from elsewhere, belongs to anyone other than the person to whom belongs that upon which it has been superposed.