Ysgol Rhos Helyg was built in 1953 by William Griffiths, the County Architect. It is a Modernist single-storey brick school with a flat roof concealed by a concrete cornice. The plan comprises of a main NW-SE block incorporating the assembly hall, kitchen, offices and toilets, a central corridor, and on the East side a classroom block with seven classrooms all set diagonally to the main axis, giving a sawtooth type plan to the NE elevation.
The interior is planned around the central corridor running the length of the building. Because the classrooms are placed at an angle, outside each classroom is a small open triangular space in the corridor intended for use as cloak rooms. The corridor is top lit by means of round lantern lights with frosted glass. The classrooms are higher than the corridor and have replaced windows above the level of the corridor roof. The stage has a foundation tablet set into the front, while the proscenium has a disc frieze and is carried on pilasters with horizontal fluting. The hall has two concealed ceiling beams on wall shafts with similar fluting.

It is listed as an exceptional and unaltered example of the modernist style favoured in post-war school architecture, used here, rarely, for a small village primary school.

Source:- Cadw listed buildings, NJR 18/11/2009