The external character of the house, and much of its internal plan, is that of a late C17 or early C18 Renaissance farmhouse. However, elements of the structure visible internally seem to be indicative of earlier origins: the scale and quality of carpentry in a ground floor room seems more consistent with a late C16 date. It is perhaps part of an earlier house on the site which was incorporated within a Renaissance rebuild. It also received limited remodelling in the early C19 - from which period the staircase and some other internal joinery appears to date. The farm is thought to have been one of the principal farms of the earls and marquisses of Worcester, growing corn to support the large household at Raglan castle. In the mid C18, the Rev. Henry Burgh, son of John Burgh, who was the chief steward of the Duke of Beaufort, lived at Penrhos.

It is a large Renaissance farmhouse with roughcast walls and a hipped pantile roof. The tall brick end-stacks have stone bases with offsets and C20 brick flues with simply moulded caps. It has a symmetrical two-storey South front. The upper wall is coved below the eaves and the first floor has four two+two pane casement windows, with flat window-heads and painted brick sills.
The centre wall carries the Beaufort crest with coronet and at thet first floor level there is a continuous string course. On the ground floor, there is a central entrance doorway with a gabled hood, slender scrolled consoles, and C19 6-panel door. The ground floor window openings are segmental arched with painted brick sills. All the windows throughout were renewed c2000 with timber casements. The rear elevation has a centre full-height stair wing with a hipped slate roof, flanked by cat-slide continuations of the main roofline (with roof-lights added c2000) which is enclosed at ground floor level by a large C20 lean-to.

Soure:- Cadw listed buildings, NJR 29/09/2008