After spending more than two years and some £41 million (€52m) on its purchase and refurbishment, the Government will officially open Farmleigh on Saturday. Not everyone will be impressed by the results. Running to 40,000 sq ft, the Victorian property possesses a certain tawdry splendour but little real beauty.

And while some of the money has been spent on necessary but invisible work such as upgrading the plumbing and attending to the roof, part of the budget went on the installation of a swimming-pool and gym in Farmleigh's basement.

Above all, it has to be asked whether the State should have spent so much money on an architecturally insignificant house at a time when far finer buildings throughout the country continue to suffer from seemingly wilful neglect.

Set in 79 acres of grounds at the north-west corner of Dublin's Phoenix Park, for more than a century the house was the residence of the Earls of Iveagh, the senior branch of the Guinness family.

It will now provide accommodation and facilities for visiting dignitaries and act as a venue for important Government meetings. The State purchased Farmleigh from the Iveagh Trustees for £23 million in June 1999 and has since spent a further £18 million (€22m) upgrading the property.

Clad in Portland stone, Farmleigh's external appearance dates from the final decades of the 19th century, following its purchase by Edward Guinness, first Earl of Iveagh. Internally, the house reflects late-Victorian taste at its most brash and eclectic with no one style predominating.

Two architects - James Franklyn Fuller and William Young, neither notable for the originality of his work - were originally responsible for Farmleigh's design and their indiscriminate plundering of historical styles is confirmed by every space in the building: an oak-panelled diningroom which owes a debt to the late 17th century; a morningroom which contains an Adamesque stucco ceiling, possibly original, but more likely dating from the fin-de-siΦcle Adam revival; and a ballroom in which the delicacy of French 18th century decorative plasterwork has been applied on an elephantine scale.

The overall impression is one of robust blowziness. Among the more successful elements is a substantial conservatory dating from the early 1900s; this has been impeccably restored and restocked. Less successful, however, is the insertion of a large and spectacularly ugly metal fire escape protruding from the rear of the house and leading to the first floor.

While the bedrooms on this floor retain their original features in which quantity of scale was given precedence over quality of detail, those above have permitted a degree of imagination to the Office of Public Works, the organisation responsible for Farmleigh's restoration.

Although almost all the workmanship is Irish, inspiration for the second floor's decoration seems to have come from inter-war French design, evident in such details as the doors of the main "de Valera Suite" which are inlaid with ebony on one side and sheeted in gold leaf on the other.

Almost all the top-floor furniture, designed by the likes of Duff Tisdall and Michael Bell, is superior to that found on the lower storeys where a mixture of antiques and reproduction items have been used. Unhappily typical in this respect are the chairs and sofas in the study, a jumble of pieces united only by the use of brocade on the upholstery and cheap gold paint on the frames.

This might not matter were it not for two important considerations, the first being that given the enormous amount of money spent on Farmleigh every last detail should have been of the highest quality, definitely not the case at present. Secondly, and more importantly, Farmleigh itself is a building of no historical or architectural merit; for the Cabinet which approved its purchase, presumably the house's principal attraction was convenience of location close to the city centre.

Successive Irish Governments have not been generous towards a diminishing stock of important houses here: in Co Kildare, Carton was offered for sale to the State on more than one occasion and refused and Castletown, which was given free to the State in 1994, has so far received only in the region of £5 million (€6.35m) from the Government.

That so much more was provided for Farmleigh is difficult to justify, especially since the house's decoration remains unsatisfactory.