Original station (1874-1909)

On opening, the Port Erin terminus consisted of the mainline, a run-round loop, departure siding, and two further sidings one serving the original locomotive shed and the other for goods. The original station building was almost identical to the one that survives at Castletown, but was constructed of slate rubble.

Until the beginning of the 20th century, the station facilities were all to the west of the pedestrian level crossing that bisects the later Edwardian station. The rather limited facilities reflected both the comparative newness of Port Erin as a seaside resort in the early 1870s, and also the financial difficulties faced by the Isle of Man Railway in completing the South Line. However, after the opening of the railway, Port Erin developed rapidly, overwhelming the original facilities which were systematically replaced from 1902 to 1905, with further extensions in 1912 and 1914.

Replacement station (1909)

The main station building is constructed of Ruabon brick and was constructed in 1909 in the centre of the village, replacing a similar original version that was slightly smaller and made of local stone. This building is something of a focal point in the village and houses a booking office, a waiting room which was once a ladies only facility and a café in the former porters' office. This building was extended in the mid 20th century: the extension is now the mess room for locomotive crews, though it was built as a ticket office for Isle of Man Road Services, a subsidiary of the railway company. This extension, which also provides part of the station toilets, has in the past been home to the local Royal National Lifeboat Institution charity shop among others. It is proposed to remove the former bus office, install a new entrance to the station toilets from the street side of the building, and install a new canopy along the street side of the building. This will allow bus services to be moved from the present shelter on Bridson Road.

Locomotive shed (1907)

There is also a substantial locomotive shed constructed from local stone adjoining an old bus garage which is home to the railway museum, replacing the 1874 version which stood beside it; this shed was constructed at the turn of the century and houses an inspection pit and one set of rails with access at both ends. Between 1982 and 1998 it served as the goods shed and housed two disused locomotives, No. 8 Fenella and No. 9 Douglas, both of which were privately owned but could be viewed from the exhibition hall of the main museum. Throughout this time the goods shed was used for servicing and housing of service locomotives.

Goods shed (1908)

The goods shed was constructed at the turn of century in a similar style to the locomotive shed and also featured one road with doors at either end. Between 1982 and 1998 it was used as the locomotive shed, being fitted with an internal water tank and inspection pit for that reason. At this time is also lost its stone walling at the station end which was spar-dashed.

When the railway museum received a major overhaul beginning in 1998 the shed was converted into the entrance hall and souvenir shop for the museum, regaining a stone gable with the addition of an entrance porch in a similar sympathetic style.

Restoration (1990-1991)

Following extensive refurbishment, the station won an Ian Allan Heritage Railway award^[1] in 1990, but since then only remedial work has been carried out to the station's intricate and distinctively carved wooden fascia boards and other paintwork.

In 1999 the traditional "picket" style wooden fencing was removed from the platform area and replaced with tall metal security fencing (to protect the bus yard in the former platform area) which detracted from the picturesque setting.

Crossing hut (1998-2010)

A small timber-built sentry box also guarded the entrance to the station where it crosses the public highway at Droghadfayle Road and today this is used only for storage by the gatekeeper until the crossing was automated in the winter of 2012–2013. This structure replaced a much older version in 1998, which had previously seen use as an overspill ticket office at Douglas station prior to that point.

Bus depot (1975)

A large spar-dashed building in the middle of the site is the southern bus depot of Bus Vannin, erected in 1975 when the entire site was redeveloped, buses having previously been housed in what is now the railway museum. This structure was erected at the same time as the bay platform and sidings were lifted to create further bus storage.

Carriage shed (1998)

The station has a two-road carriage shed, also constructed in 1999, ensuring for the first time in the line's history that coaching stock stored overnight could be kept under cover; until this time the carriages were stored outdoors overnight on the platform, and latterly remained there in closed season attracting vandals.

Water tower (1998)

The stone-built water tower which serves the locomotive shed today was built in 1998 replacing a much older version which had been removed in 1986 and not replaced at the time. The tower is in a similar style to the original, being of local stone, and houses the station's oil store beneath the tank. It stands on the same site as the original but it slightly larger; a timber-built crew bothy stands behind it, this having been used as a temporary ticket office at Douglas station for the duration of the 2016 season while refurbishment was ongoing.

Regeneration (2016-2018)

Beginning in 2016 the station and its surroundings became part of South West Regeneration Scheme for the village; this has involved the repaving of the adjacent Station Road, removal of the perimeter walling (itself only installed in 1974 when the road was widened), and the removal of a canopy from the northwest gable of the building, this not being original. A replacement canopy in a similar style to that on the platform side of the building was installed and the former bus office (later Quilter's Haltsewing shop) demolished to create a larger paving area, the new canopy continuing round to the roadside of the building. An original feature, the miasma tower, long since removed, was reinstated atop the roof and track realigned onto a curve at the headshunt. A second phase was completed in early 2018 and has seen a sloped area leading to the adjacent railway museum created, effectively making a large new feature wall a central feature when viewed from the road. Foundations were also laid with the possibility of a short platform being added in the future beside the museum and locomotive; to date there are no plans to install this feature.