A flexible inside corner trim piece is formed with concave depressions at hinge portions where wings attach to the body. The trim piece can be formed such that wings and a top cap lay flat in plane perpendicular to body or wings and top cap curve at an angle. Hinge portions can be narrow or wide and symmetrical or asymmetrical. The trim piece can be dyed, paintable, or present another decorative surface. The trim piece can include embedded lighting.

A flexible inside corner trim piece is formed with concave depressions at hinge portions where wings attach to the body. The trim piece can be formed such that wings and a top cap lay flat in plane perpendicular to body or wings and top cap curve at an angle. Hinge portions can be narrow or wide and symmetrical or asymmetrical. The trim piece can be dyed, paintable, or present another decorative surface. The trim piece can include embedded lighting.

A decorative moulding assembly for a wall or ceiling in an interior space. The decorative moulding assembly may include a first moulding piece and a second moulding piece each having an ornamental front surface, a rear surface, and a channel in the rear surface and a connector for connecting the first and second moulding pieces together. The connector may include a first portion that nests within the channel of the first moulding piece and a second portion that nests within the channel of the second moulding piece. The first portion of the connector may include a U-shaped body having first and second legs that deflect inwardly towards one another as the first portion of the connector is being inserted into the first channel of the first moulding piece.

A decorative moulding assembly for a wall or ceiling in an interior space. The decorative moulding assembly may include a first moulding piece and a second moulding piece each having an ornamental front surface, a rear surface, and a channel in the rear surface and a connector for connecting the first and second moulding pieces together. The connector may include a first portion that nests within the channel of the first moulding piece and a second portion that nests within the channel of the second moulding piece. The first portion of the connector may include a U-shaped body having first and second legs that deflect inwardly towards one another as the first portion of the connector is being inserted into the first channel of the first moulding piece.

A system comprising a first baseboard element, a second baseboard element, and a spline configured to couple with the first baseboard element and the second baseboard element. Another system comprising a first crown element, a second crown element, and a spline configured to couple with the first crown element and the second crown element. Other embodiments are disclosed herein.

A prefabricated decorative quoin system includes an elongated edge column attachable to an existing wall corner. The elongated edge column may be formed by a plurality of elongated edge members interconnected end-to-end. A plurality of prefabricated quoin panels are attached to the edge column in vertical stacked relation. A lighting array disposed relative to an inner surface of the quoin panels may be used to illuminate the quoin panels.

A construction element is provided for forming a corner of a surface of a building, the surface including wall panels attached to framing studs. The construction element includes: a corner-forming surface that that is shaped to extend, in a cross-sectional view, between two separate wall panels, such that ends of the corner-forming surface, as viewed in the cross-sectional view, substantially match respective corners of the wall panels; and a fastener strip that, in a state in which the corner-forming surface is in its installed position with respect to the framing studs, is substantially parallel to one or more of the framing studs, such that a fastener can attach the fastener strip to one or more of the studs without passing through the wall panel.

A decorative and/or protective sleeve configured to cover a wooden beam includes a textured decorative surface, and an opening through which the beam may be inserted. The sleeve may have a faux wood surface texture to provide a fresh wood appearance and may further protect the beam from damage.

In one embodiment, a system comprises a first baseboard element, a second baseboard element, and a spline configured to couple with the first baseboard element and the second baseboard element. In another embodiment, a system comprises a first crown element, a second crown element, and a spline configured to couple with the first crown element and the second crown element. In another embodiment, a system comprises a crown spline, a baseboard spline, and a wall element configured to be coupled with the crown spline and the baseboard spline. Other embodiments are disclosed herein.

In one embodiment, a system comprises a first baseboard element, a second baseboard element, and a spline configured to couple with the first baseboard element and the second baseboard element. In another embodiment, a system comprises a first crown element, a second crown element, and a spline configured to couple with the first crown element and the second crown element. In another embodiment, a system comprises a crown spline, a baseboard spline, and a wall element configured to be coupled with the crown spline and the baseboard spline. Other embodiments are disclosed herein.