Tidd's departure, at the end of last month, comes after Churchfield's decision to postpone plans to enter the new-build market in London. One of the main reasons for appointing Tidd was to introduce Churchfield to new-build.
The former Laing Construction southern regional director joined with a brief to increase Churchfield's £70m turnover by 20% in each of the next five years.
Tidd is the second former Laing director to leave the firm this year – Brian Richardson left in the summer. Tidd and Richardson worked together on a number of projects at Laing, including the £70m Grosvenor Place building for Grosvenor Estates.
Group finance director Edwin Kirker has taken over Tidd's position temporarily, but the firm is looking at a long-term replacement. Tidd's next move is as yet unknown.
Group deputy chairman Eric Smith said he was disappointed that Tidd had left but noted that he had expressed a desire to return to the new-build market in the summer.
Smith said: "Very early into his tenure Martin found coming to Churchfield quite a culture shock. Coming from a builder as big as Laing to a small entity such as Churchfield was difficult for him. He really felt his heart was in main construction."
Smith said that the firm's focus was now on IT work such as internet switch houses, rather than new-build construction. He said: "Long term we are still looking at the new-build market. But in the short term, we are involved in IT."
Smith said the firm was working on £20m worth of IT-related work, including a project in Frankfurt.
Smith added that the recent departures were not a serious concern. He said: "That happens in life. We have lost some good people, but two more good people joined us yesterday."
Smith said that Richardson was not a long-term appointment. He said: "He came in as non-executive chairman for one day a week. It was felt by both sides that he was not getting much out of it."
Richardson is now concentrating on his role as a property adviser to the Jockey Club.
When Tidd joined Churchfield he said he was looking at acquiring public and private companies with the possible intention of floating or selling the company in five years.
Tidd said then: "It could be a high-quality refurbishment contractor or a contractor that has a track record in new-build."