In the interiors of the Style Louis XII the embrasured windows were of good size, had either square heads or very flat elliptical arches, and were usually two lights wide, divided in the centre by a substantial vertical stone mullion, intersected by one or more transverse mullions or transomes. The casements were of metal. In the less important rooms oiled linen or oiled paper were used; in the better rooms the casements were glazed with roundels or with small quarries set in lead. Inside shutters were used and, in some cases, the lower lights had also perforated outside shutters. Door heads, like window heads, were square or had flat elliptical arches.

Walls were sometimes panelled, either wholly or in part, with small panels, but were more commonly of stone or plaster, which might be painted or frescoed, but they were more frequently relieved by hangings of painted cloth or canvas or by tapestries and embroideries. Complete schemes of permanent decoration were rather exceptions than otherwise but gradually came more and more into vogue under spreading Italian influence. The motifs used in the panelling, medallions and other carved, sculptured or moulded features of door and window trim or wall decoration were a medley of Gothic and Renaissance details.

Fireplaces, with their surmounting chimney-pieces, afforded an opportunity for rich and imposing struct ture and a wealth of carved detail. Some of the structures left the fire largely exposed at the sides, the hood receding upwards from a bold vertical mantel whose weight was carried on half-piers or corbels; other overmantel structures consisted of an elaborate pilastered and panelled architectural composition carried up vertically part or all of the way to the ceiling and resting on a vigorous vertical mantel which, in turn, was supported on a pillared substructure that left only the front of the fireplace open.

Ceilings were either vaulted, with a more or less complicated system of ribbing, or else of wooden construction with the timbers, as a rule, exposed to view. At times the timbers were concealed by temporary cloth or tapestry testers attached by hooks. In other cases, the ceiling timbers were boarded in the manner of a barrel vault with wooden rib divisions. Panelled wood ceilings, with square, hexagon or octagon-shaped panels, affixed to the under side of joists gradually appeared as a result of Italian influence and were frequently enriched with colour and gilding.

Flooring consisted of stone slabs, of bricks, of encaustic tiles and also, as a direct outcome of Italian teaching, of maiolica tiles and of parquetted wood.