Elmside including boundary wall and gate

Elmside is a two-storey house with attic storey, designed by E.S. Prior and built in 1885, with a single-storey addition to the south added around 1900. The building is constructed of red brick laid in English bond with sections of red hung tiles and plain tiled roofs.

The house faces east onto Grange Road and is roughly rectangular in plan, with a single-storey rectangular projection to the north elevation and a single-storey rectangular extension to the south elevation built around 1900. It was designed in the Arts and Crafts style, with sections varying in height from single-storey to two storeys and attic storey. The northern section of the main house features a mansard roof, while the southern section combines multi-faceted hipped, pitched and flat roofs with one dormer window on its east slope. The single-storey projection to the north is hipped, and the extension to the south is half-hipped and gabled to the west with a central rectangular hipped lantern. Five red brick chimneystacks rise from the multiple roof slopes.

The front elevation to Grange Road is composed of four parts: a rectangular single-storey block to the north; a tall north block with an attic storey over a doorway; a south block of two storeys with a dormer window; and a rectangular south block of one window bay built around 1900. The east elevation is composed of red brick laid in English bond with red plain tiles hung to the first and attic storeys over the front door. The main entrance is a timber door at the centre of the east elevation, with two raised and fielded panels under a plain overlight of three panes. It is framed under a flat canopy supported on two square timber piloti, which may have been added at a later date. Above the door at first floor level is a three-light casement window to the first floor and a two-light casement window to the attic storey, all framed by hung tiles. To the right of the door is a three-light casement window, and to the left but set back from the door, a five-light casement window illuminates the interior stair hall. To the left of this is an elaborate Venetian style window, having a segmental-headed casement window with a fluted keystone set within a fixed-paned window and surmounted by a small pediment. This window style is characteristic of Prior's work, as a similar example exists at his addition to the Red House at Harrow (1883-4). On the first floor above the Venetian window is a three-light casement window, and an attic dormer with two casement windows above.

The garden or west elevation is also composed of red brick with red clay tiles hung to the first floor of the southern section, splaying over the ground floor windows and supported by carved brackets with pendant ball finials. The second floor gable of the garden elevation is half-timbered. The ground floor is nearly continuously glazed over a red brick plinth with original Venetian style windows comprising segmental-headed casement windows with fluted keystones set within multi-paned fixed windows. The first floor features four bays of three-light casement windows and one two-light casement window, with a two-light casement window in the apex of the attic gable. A half-glazed door leads from the kitchen to the garden and stands under a roofed canopy supported by two square-plan timber piloti.

The north elevation to Herschel Road has a casement window to the service stairs, a two-light casement window at first floor level, and two two-light casement windows to the attic storey of the mansard roof.

The single-storey extension added to the south around 1900 has an oculus window and four four-pane windows, one of which is infilled, to the west gable. The extension has a three-light casement window to both the east and south elevations, featuring hand-painted glass to the upper panels. Another single-storey extension was added to the south in the late twentieth century; this is not included in the listing as it does not contribute to the special interest of the principal building.

The interior of Elmside was adapted for use as student accommodation around 1970 and consequently does not retain many interior features. Within the entrance hall the original stairs survive, curving elegantly to meet the first floor landing and well lit by windows on the east elevation. The newel post is extended to ceiling height and doubles as a pier of an arch, displaying finely carved fluting. To the south of the entrance hall, a bedroom contains original bookshelves and cupboards and may have originally been in use as a library. To the west of the entrance hall, partitions have been inserted to create dormitory rooms, and as a result two fireplaces, which would have served the grandest rooms, are now located on the east walls of a narrow late twentieth-century corridor. One fireplace is of plain carved limestone, and the other is a painted carved fireplace with fluted brackets and pilasters. On the first floor, the landing opens to a corridor with bedrooms to the west and north. The first floor corridor contains some arched openings, one with an oval borrowed light, and timber cupboards, alluding to former interior decoration. The service stairs in the north block have been replaced in the late twentieth century and allow access from the ground floor to the first and attic storeys. The attic storey accommodates a self-contained apartment with a lobby, double bedroom, kitchen, bathroom and living room.

The single-storey extension to the south of the house, built around 1900, has recently been adapted for use as a reading room forming part of the Ashby Library. Colloquially known as the 'Magic Room', it reflects Rouse Ball's interest in magic and mathematics, which can clearly be observed in the painted windows depicting mathematical puzzles, coats of arms and symbols of the occult.

To the east of Grange Road are attractively carved timber gates and gate posts. A red brick screen wall bounds the site to the north to Herschel Road and features a segmental-headed gate opening and timber-battened door. The screen wall continues around the corner of Grange Road to meet the house and contains a raised segmental-headed opening, which would have given access to the service areas of the house in the late nineteenth century. The remainder of the site is bounded by modern timber boarding.