[3] The main line was sextuplicated in 1927 in association with electrification works; with these changes, a new pedestrian subway was built in 1926 and the Up Suburban platform demolished.

[3] Up until the 1980s, a few morning peak services from the North Shore line called at platform 1 for the benefit of Newington College students.

[3] The integrity of Stanmore Railway Station as a whole is considered to be high based on the fact that the platform buildings, the subway, and the parcels office are rarely seen so intact on the one site.

[3] The "second class station" building is flanked by attached wing structures with a combination of hipped and gable roof forms.

There are transverse gables, which face north and south, and feature decorative barge boards, finials and ridges.

[3] Air-conditioning units and modern services and conduits have been fixed to the brickwork and in front of windows on the northern elevation of this building.

The awning structure consists of timber beams with stop chamfers, and purlins with beaded edge detail, supported by original cast iron columns (which have NSWGR insignia) with new corrugated metal roof sheeting.

The store room adjacent to the Station Manager's office has (possibly original) floorboards and timber ceiling lining.

There is a pair of double leaf panelled doors and original windows, with timber architrave and sill boards, all in sound condition.

The waiting room, adjacent to the ladies toilet, has an original ceiling rose, door, windows and architraves and has a dado rail and skirting which is in keeping with the age of the building.

[3] The building was reported to be in good condition at the time of heritage listing, although a few surface cracks had developed in the brickwork.

The brick wall to Trafalgar Road has been extended to both the east, to full height adjacent to the former ticket window, and to the west to provide toilet facilities.

The waiting area to the central section has timber lining boards to the ceiling, with a beaded profile and a scotia moulding.

[3] The original door, windows and architraves remain with dado rail, skirting and wall vents which are in keeping with the age of the building.

Unsympathetic repairs, to the roof in particular, graffiti and adhesive marks on the brickwork do somewhat reduce the integrity of this buildingbut can be remedied.

The covered stair to Platform 1-2 is a painted timber-framed structure with lining boards over rafters, which is in good condition.

The timber elements are all fairly plain except at the entrance to the platform where there are stop chamfered posts and mouldings to rafters.

[3] The subway has been changed but it also retains original fabric namely the brick walls, the steel girder and concrete ceiling.

[3] Stanmore railway station was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.

The 1880s platform buildings, the 1910s former parcels and booking office and the 1920s subway collectively represent key historic phases of suburban railway development.

[3] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

The former parcels and booking office is an example of the Federation style architecture prevalent in late 19th and early 20th century suburban railway stations.