Despite being one of Dublin's most prolific builders, Mr Liam Carroll maintains a low public profile.

The Dundalk-born mechanical engineer, who became the main engine of urban renewal in Dublin, has never given a formal press interview.

He values his privacy and eschews the badges of success, such as expensive cars and tailored suits. He drives an ordinary car and maintains the image of an average construction worker, dressed in shirt, pullover, anorak, jeans and wellingtons.

But the extent of his building projects is far from ordinary. Since the early 1980s, Zoe Developments has built around 60 apartment schemes in Dublin, ranging in size from an early 60-unit complex in Sandymount to the controversial 330-unit scheme at Bachelors Walk.

Low pricing has been the key to the company's success. Its developments have tended to be in unfashionable, often tax-designated areas such as the north inner-city. The company has also been notable for its ability to develop several sites simultaneously.

Mr Carroll did not employ a single qualified architect to design any of his earlier schemes; instead, he designed them himself and had a team of technicians "work up" the drawings. He once claimed that architects were "only interested in designing penthouses for fellows with Mercs".

Critics say Zoe's lack of architectural advice and Mr Carroll's own devotion to meeting minimum standards are reflected in the quality of many of his schemes, particularly the earlier ones. Purchasers got small single-bedroom apartments laid out on long, narrow, artificially lit corridors. Balconies, where they were provided, were of the clip-on variety with just about enough room for a few pot plants. Storage space was non-existent and the "landscaped courtyards" were merely car-parks with trees.

It was only in the second half of the 1990s that Mr Carroll engaged architectural advice; first from a Malaysian architect, who designed Zoe's scheme at Gardiner Street and Parnell Street, and later the firm of O'Mahony Pike, which is responsible for Charlotte Quay, which includes a 16-storey tower.

Zoe has also had problems with health and safety controls at a number of its sites, which resulted in a High Court case against the company in 1997.

During the case Zoe Developments was denounced by the High Court judge as a "recidivist criminal" for breaching safety standards on its building sites and Mr Carroll was described as "a disgrace to the construction industry". After prompting from the judge, Mr Carroll offered to pay £100,000 (€127,000) to charity to demonstrate his "contrition" for consistent breaches of health and safety regulations.

Mr Carroll buys all the sites personally rather than at arm's length through estate agents. One of the secrets of his success is his prowess at site assembly, and he is reputed to go back again and again to reluctant vendors until he clinches a deal. He has also rarely had to contend with a refusal from Dublin Corporation's planners.

Mr Carroll now lives in Mount Merrion, Co Dublin. His wife, Roisin, is also a director of Zoe Developments.