As an architect he is often compared with his friend and English counterpart Augustus Pugin, with the vast majority of his buildings completed in the Gothic Revival architectural style.

[3] In 1843 Wardell made the then conventionally unusual decision to convert from Anglicanism to Roman Catholicism, adopting the motto Inveni Quod Quaesivi ("I have found that which I sought").

[4] Dominating this room was an ancient carved wooden French cross that now belongs to the Melbourne Diocesan Historical Commission, who also own several other mementos of his personal devotion.

He was commissioned by Robert Hope-Scott and his wife, of Abbotsford, Melrose, to build a church for the growing Roman Catholic community in the nearby town of Galashiels, Scotland.

The expected paraphernalia of the more ritualistic Catholic worship is absent; side chapels and numerous secondary altars are conspicuous by their absence.

The only contemporary jarring feature not found in an English country church is the set of late Byzantine style gilt chandeliers.

[14] Other Grade II* listed heritage buildings designed in part or full by Wardell include the Church of St Mary and St Michael in the London Borough of Tower Hamlets;[15] the Roman Catholic Church of St Peter and St Edward in Palace Street, Westminster;[16] the Gate Lodge and Gateway, the Training College, the Priory, the former convent building, and the chapel at the former convent of the Holy Child Jesus on Magdalen Road in Hastings;[17][18][19][20][21][22] Ellingham, a house in Thanet, Kent;[23] the Old Lodge and Chapel of the Sacred Heart of Digby Stuart College;[24] a lodge at Grove House in the London Borough of Wandsworth;[25] the Spode Pottery including buildings around the north west courtyard, including the entrance gate, gate piers and remains of the bottle kiln at Stoke-on-Trent;[26] and a chantry chapel for family burials commissioned by Lord Petre at Thorndon Park, near Brentwood, Essex, his last completed work in England.

Robbery was commonplace, and the poverty caused by the soaring inflation, and streets that were in 1854 described as open sewers ensured that disease was rife.

Within ten years the gold rush had transformed Melbourne from a provincial outpost of the British Empire to a wealthy and rapidly expanding city.

This need for building coupled with available funding drew aspiring young architects from around the world, among them John James Clark, Peter Kerr and in William Wilkinson Wardell.

As the newly arrived and appointed Government Architect, Wardell immediately began work on St Patrick's Cathedral, a task which was to occupy him for much of his life.

In 1867 the Wardell Family moved into a large new house known as Ardoch, at 226 Dandenong Road, St Kilda, at the time one of the smartest and most expensive residential areas of Melbourne.

In Melbourne, Wardell was not only the state-employed Government Architect, but also had a flourishing private practice as well, building houses, shops, and business premises for all who could afford him.

His mission, considered radically left wing at the time, was to redistribute the grazing land of Victoria, and to introduce a bill providing for the payment of members of the Legislative Assembly, which would enable working-class candidates to be elected.

During his time in Melbourne, Wardell designed numerous buildings, including 14 parish churches, in both the private and public sectors.

Bishop James Alipius Goold commissioned the first in 1850, delayed by labour shortages caused by the Gold rush, and in 1858; he then laid the foundation stone for a second, larger, church partly completed by 1858, when he instructed the newly arrived Wardell to design a cathedral, incorporating as much as possible of the partly completed church, and in December 1858 the new plans were accepted and work commenced.

Wardell's design is a fine essay in the mid 19th century Gothic Revival style, drawing inspiration from the mediaeval cathedrals of Europe and England.

The nave is Early English in style, with traceried windows more typical of the later Decorated Gothic, while the apsidal chevet chapels, ambulatory and sanctuary, are based on French models.

Wardell was the chief architect, assisted by J.J. Clark and Peter Kerr; work commenced in 1871 and it was declared open at a ball attended by 1,400 people in 1876.

[34] Government House was designed by Wardell in the Victorian Italianate style; its likely inspiration was Queen Victoria's summer residence Osborne House on the Isle of Wight, England, built between 1845 and 1851, inspired by palazzi of the Italian Renaissance, which has similar detailing, picturesque massing, campanile-style towers, and royal associations.

It consists of three separately articulated blocks housing different functions, each with their own entrance, asymmetrically arranged with a dominant central tall belvedere tower.

The three-storey principal block contains the state rooms for official entertaining, a secondary two-storey wing to the north contains the private apartments of the vice-regal family.

Designed by Wardell in the Pre-Federation Anglo Dutch style for the Australasian Steam Navigation Company and completed in 1885, it had distinctive Flemish gables and a bell tower, which has ensured it has "long been regarded as a significant Sydney landmark".

[35][36] Wardell also designed the New South Wales Club House building at 31 Bligh Street in the Victorian Academic Classical style, completed in 1884; and is currently occupied by the Lowy Institute.

[39] Wardell died at his home, Upton Grange, in Edward Street, North Sydney on 19 November 1899 of heart failure and pleurisy.