Early history of the site
The former Auckland Electric Power Board (AEPB) Substation lies near the western slopes of One Tree Hill (Maungakiekie), the site of a large pa occupied for several centuries prior to colonial arrival. According to one perspective, a community was established on the hill at some time between the fifteenth and seventeenth centuries by Ngati Awa chief Titahi and his people, who had migrated to the area from Northland. By the early eighteenth century Maungakiekie was the domain of Te Waiohua, whose leader Kiwi Tamaki increased its defensive capabilities. The Auckland isthmus was subsequently conquered by Ngati Whatua in 1741, after which Te Taou chief Tuperiri is said to have built a new pa on the site which he renamed Hikurangi. Tuperiri is stated to have still been in residence in the 1790s.
Subdivided into farms as early as 1842, the wider Epsom area became renowned for its large country homes and later as a prestigious suburb. The site on which the AEPB substation was later erected straddled the boundary of two 1842 Crown Grants (Allotments 29 and 30). The land parcels, two of several settler farms in the area, lay near a windmill constructed in circa 1843 for William Mason (1810-1897) New Zealand’s first Superintendent of Public Works. John Bycroft, who bought the mill in partnership with another, owned Allotment 30 from 1847 but sold in 1861 after which the land was frequently subdivided.
Residential development in the southern part of Epsom accelerated in the early 1900s as the suburban location became increasingly accessible due to electric tram services and the private motor car. The future substation site, created in 1914 as part of the extension of a residential development promoted as the Town of Tui, changed hands a number of times prior to its purchase in May 1929 by the AEPB. An existing house was removed to enable construction of an electricity substation to serve the recently reticulated Epsom area.
Electricity supply in Auckland and the reticulation of Epsom (1900-30)
Construction of the Epsom electricity substation occurred in 1930 and was part of the broader development of a publicly owned, unified electricity transmission system to connect diverse isolated facilities in the North Island. The proposed Epsom utility was linked to the widening use of hydro-electric power and efforts throughout the 1920s to create mass consumption through ‘load building’ to provide the economies of scale associated with the development of power stations on Mangahao, Arapuni and Waikaremona. Domestic electricity use, mostly limited to lighting and ironing in the 1920s, expanded after 1925 the year Dunedin-based Shacklocks began to manufacture electric stoves.
Electricity was first used in New Zealand in 1861, but it was not until the State Supply of Electrical Energy Act 1917 and the Electric Power Board Act 1918 that supply was statutorily acknowledged as an essential part of the country’s infrastructure. Under the new regime the state assumed primary responsibility for construction and operation of generation projects and the supply of electricity at wholesale rates to specially elected local authorities via government substations. Supply authorities retailed the energy through their own secondary transmission systems, in which electricity substations converted current from the grid network to a suitable voltage for local consumer supply.
The AEPB was established in 1922, and was the first of the three power boards in place in the Auckland region by 1924. Charged with distributing electricity to New Zealand’s largest commercial centre, the AEPB administered a supply area taking in the Eden and Manukau Counties. The new body took over the assets of the Auckland City Council Electricity Department founded in 1908. In 1922 a coal-powered thermal station constructed at Kings Wharf in 1913 was the main source of electricity supply.
Electricity mains had been laid in Epsom as far as Owens Road by mid 1915. Growing electricity demand had overtaken planned supply from an ‘Epsom Substation’ opened in Gillies Avenue in 1917. Reticulation of the wider Epsom locality was well underway by 1923.
To popularise electricity use in the home in anticipation of supply from the Arapuni hydro-electricity project then under construction on the Waikato River, the AEPB introduced a domestic tariff in late 1924 to reduce the cost of power to potential residential consumers. By 1926, the government had interconnected existing electricity generation plants in the Auckland and Waikato regions. Electric ranges were increasingly being installed in homes by the late 1920s, along with storage water heating and other appliances, the cost of which was dramatically dropping. ‘The “all electric” home, it was said, would relieve women from domestic drudgery and replace the domestic with the “electric servant”’. Although electricity generation commenced at Arapuni in June 1929, geotechnical problems extended Auckland’s reliance on the Kings Wharf source until April 1932.
Construction of the Epsom substation (1930)
The Epsom substation was built in 1930, the year the AEPB celebrated the opening of its eight-storey Art Deco headquarters on Queen Street.
Extending an earlier Auckland City electricity framework that included existing substations at Gillies Avenue and Ponsonby, the Epsom facility was one of three new substations under construction in 1930 as part of an expanding distribution network. The two others erected in1930 were located in Minto Road, Remuera and Great North Road, Point Chevalier. All three were built in residential neighbourhoods, within a block of local shopping centres and major arterial roads.
Early New Zealand substation buildings were traditionally designed with high roofs to enable power lines to be brought to the structure while maintaining adequate safety clearance. By incorporating cable trenching in the sub-floor of the Epsom structure, an architecturally traditional tripartite classical design with a flat roof was possible.
Reflecting AEPB’s municipal origins, the Epsom substation building was of Stripped Classical design with Art Deco influences, a modern interpretation of the classical style favoured for public buildings on account of associations with grandeur and stability. The design expressing strong lines invited public confidence in the safety, worth and long term viability of electricity as a new energy form.
The façade and the south elevation of the tall, brick structure were divided into rectangular bays by pilasters. Metal-frame windows and cement plaster dressings expressed modernity. The incised lettering ‘AEPB 1930’ matched the clean lines of plasterwork elsewhere on the structure, and a stylised flower-like symbol and strigulation possibly represented hydro-electric power generation. Aspects of the form of the building were influenced by its function. Sizeable doors enabled the positioning or removal of plant with minimal risk and loss of time. Louvre doors and a roof vent induced natural ventilation, assisting temperature control for the transformers.
Internally, a mezzanine extended along the centre of the building and adjoined the transformer bays. A gantry crane, an internal fixture, enabled heavy machinery to be lifted into place. Pairs of windows (one upper, one lower) in the front bay, and the bays along the south elevation provided natural light to the interior. A low brick wall ran along the front boundary.
The identity of the designers of the AEPB substations of the era is not known. The lack of a name or accreditation to an architectural or engineering practice perhaps suggests that the plans were prepared by the AEPB. Revisions made just days before the building permit was issued could indicate the hand of an Auckland-based draughtsman. It has also been suggested that A.M. Bartley and H.G. Wade, the architects the AEPB’s Queen Street headquarters opened at this time, might have played some role.
The construction contract was won by builder Bert Grinter (1882-1974) who had worked as a builder on his own account in the South Island for over a decade before relocating to Auckland in 1922. In 1925-6 Grinter had won the contract for construction of Stoneways, the Epsom residence of eminent Auckland architect William Gummer.
Subsequent use (1931 to present)
Epsom was fully reticulated for electricity by the early 1930s. Local residents to benefit from the new service would have included AEPB secretary-treasurer Norman McLeod Speer (1894-1963) and the general manager Howard Bartley (1886-1959) formerly AEPB chief engineer. By 1939 most of the North and South Island were internally interconnected, and electricity was being supplied to 92 per cent of the population.
Increasing electricity demand resulted in cuts of 20 per cent being imposed on the electrical supply authorities between March and August in 1946 and 1947. The AEPB responded by disconnecting residential areas in rotation for 30 minute periods. Concerned that the measure was insufficient, the use of domestic water heaters was prohibited during prescribed hours. Those caught taking a hot bath outside the permitted times faced a £200 fine or twelve months in prison.
The following year, in 1948, a two-bay concrete addition was made to the rear of the Epsom substation to accommodate two, more efficient transformers. The window in the rear wall was bricked up and a lavatory cubicle may have been constructed in the corner of the building at this time.
In 1951, the original transformers were removed from the four rear bays of the substation. The associated north-facing louvre openings were bricked in and plastered, enabling use of the internal space for equipment storage. At this time also, the remaining three 1930-era transformers were replaced by more efficient models similar to the 1948 equipment.
Construction of a high capacity inter-suburban traffic route to link Balmoral to Green Lane and the Auckland-Hamilton motorway in the 1970s increased the visual prominence of the Epsom substation. The adjoining residential properties in the vicinity were acquired and demolished to facilitate construction of the new route, leaving the 1930 substation located at a busy intersection. Public views of the facility were no longer confined to the west elevation facing The Drive.
In 1972 the AEPB expanded the size of its holding by acquiring the remaining residential property between the substation and Green Lane West, and constructed a freestanding concrete block transformer structure of four bays. Unlike the earlier building, the design of the new structure was primarily utilitarian, although at least one wall incorporated bands of decorative breeze-blocks. The three surviving (1951) transformers were removed from the original substation, freeing up the structure for control gear, a seven-panel 22 kV switchboard and the storage of equipment.
National electricity shortages in the 1970s, at times the result of abnormally dry conditions affecting storage lakes, brought a reduction in television broadcasting hours, cuts in hot water, and some daily blackouts over several months in the winter of 1973.
The primary voltage of the Epsom substation was upgraded from 22 kV to 33 kV in 1977, the year an adjoining residential property to the south was purchased. Following use as a temporary AEPB depot, the recently acquired property was subdivided and returned to residential use in 1991. The 1972 structure located to the northeast of the original substation was altered in circa 2000 with the addition of a roof over what was formerly the open half of the building.
In 1986 economic reform of the state electricity sector saw the creation of the Electricity Corporation of New Zealand. Following subsequent reform of electrical supply authorities, the AEPB was corporatised in 1994 and became Mercury Energy Limited, a company owned by the Auckland Energy Consumer Trust. To comply with a later series of reforms, Mercury sold its electricity retail business in 1999 along with its interest in electricity generation; and changed its name to Vector Limited.
In 2002, the year Vector became New Zealand’s largest multi-utility company, the 1948 addition to the Epsom substation was demolished and the 1930 structure was refurbished. A door was added in the rear wall. Maintenance work was undertaken on the interior, which accommodated a switch room, storage areas, a mezzanine, toilets and passage. The building’s historic gantry crane was retained.
In the grounds, rail tracks between the 1930 substation and the 1972 structure were removed, the concreted access between the two buildings was re-laid and new planting was undertaken. Security lighting was installed, highlighting the west façade.
The place remains in use as a public utility and continues to serve the broad purpose of local electricity distribution.
