Fernside is a generous and luxurious five-bedroom white-weatherboard slate-roofed American Colonial Revival style house with an L-shape plan.

Set by the Tauherenikau River on the plain below the junction of the Tararua and Rimutaka ranges Fernside was built in 1924 to replace a house destroyed by fire.

The current building is the work of the educated tastes of client, Ella, Mrs Charles Elgar and her 29-year-old architect, Heathcote Helmore.

The house is near Featherston down a tree-lined mile-long (1.6 kilometres) drive from State Highway 2 and surrounded by 12 acres of expertly maintained and landscaped gardens.

This location let not-quite-absentee owners of remote coastal sheep stations live with easy access to the railway, main roads system and later, at the local Tauherenikau Racecourse, an airfield.

Though built of timber —in view of the 1942 Wairarapa earthquakes, fortunately — it was conceived as a brick building and the working drawings were made on that assumption.

In 1876 it was bought by Richard John Barton (1846–1879) of White Rock Station[notes 1] and his wife, Pihautea-born[2] Catherine Carne Bidwill.

The Evening Post reported: “A large sum of money has been spent on the grounds" and how H. R. Bunny, in his speech thanking host and hostess on behalf of the club's committee, "remarked that a wilderness of fern and manuka had been transformed into a veritable paradise”[15] The Elgar's homestead [notes 3] of 20 rooms [16] and its contents were totally destroyed by fire in November 1923.

[17] Being heavily insured the Elgars appointed Heathcote Helmore to design a new one and promptly departed overseas to buy antiques and furnishings for their new home.

They travelled to England in July 1920 on the ship S.S. Ionic with the retiring Governor-General and when they docked in Newport News took up his offer to take them in Liverpool's car to Yorktown where the young men took a deep interest in the colonial architecture of Virginia.

At the suggestion of the same son-in-law Sir Edwin Lutyens invited Helmore to work, sometimes directly with him, on the detailing of the interior of Queen Mary's Dolls' House.

[18] Charles Elgar died suddenly in the luncheon interval of the Easter Saturday 1930 race meeting at the neighbouring Tauherenikau Racecourse.

With his brother Martin, he competed with other woolgrowers to create the ideal breed for New Zealand conditions, their contribution was to Border Leicesters.

New Zealand's first ambassador from the United States, Robert M. Scotten, appointed in late 1947, arranged his government's purchase of 38 Fitzherbert Terrace (built 1926 to the American Colonial Revival designs of the same firm, Helmore & Cotterill,[18] demolished for the motorway) in Thorndon, Wellington in July 1948 as an official residence.

[29] To cultivate people in government and of wider community influence with considerable style, and well away from Wellington, Scotten and his wife also occupied 70 kilometres distant Fernside as their country residence.

They have restored the house and its contents to the fine 1920s style and high standards of Mrs Elgar and make a continuing major investment in its surrounding gardens which are sometimes opened to the public.