4 Trillo Avenue

4 Trillo Avenue is a building featuring white roughcast render and Llanberis slate roofs, with axial and end wall stacks that are stepped in profile. The structure has characteristic unmoulded chamfered angle brackets that support the roof overhang, and the windows are designed with slight swept heads. The entrance is located in the gable end facing the street, with a secondary porch gable offset to the right of the main gable. The doorway has been renewed with an added lean-to porch, and there is a 2-light casement window above the entrance. The main gable has an asymmetrical roofline that sweeps down low to the left side. A 4-light casement window with shutters is present in the main gable, with an offset 2-light upper window.

On the northeast elevation, the roof sweeps down low over a lean-to projection on the ground floor to the right, which has altered openings. There is a 2-light casement window with shutters next to this outshut, along with small paired round-arched openings. The outshut wraps around a long catslide dormer that features 2-light casement windows at either end. Additionally, there are 2-light casement windows on either side of the chimney in the gable wall.

The southwest elevation shows the roof sweeping down over a loggia to the right, where recessed French windows are located. Above this, there is a low catslide dormer. The flush gable is off-centre and has a 3-light casement window with shutters pushed towards the angle, accompanied by a row of four narrow round-arched lights to its left. A 3-light window is also present in the gable.