Fulfilling the dream of his mother, Letty Manners - who had grown up amid the restoration of Haddon Hall in Derbyshire - that one of her five sons should become an architect, Jeremy Benson studied at the Architectural Association and then practised privately, founding the partnership of Benson & Benson (later Benson & Bryant) with his wife, Patricia Stewart, in 1954.
He applied his enthusiasm and sensitivity to the repair of many great buildings, including Sezincote, Stanway, Hidcote Manor Garden, Batsford, Nether Lypiatt, in Gloucestershire, Bodiam Castle in Sussex, Honington in Warwickshire and Winslow Hall in Cheshire, and to smaller jewels such as the medieval cottages at Tewkesbury, working for many years as consultant architect to the National Trust, and setting new standards in conservation.
Following the collapse of the Barber Boom in 1973, commissions were few and far between, so he turned his talents to mitigating the effects of the Labour government's proposed Annual Wealth Tax and Capital Transfer Tax, which threatened to strip the owners of thousands of Grade I historic houses of their means of maintenance within a generation.
He had already, in 1972, founded the Joint Committee of National Amenity Societies to influence the proposed redevelopment of Whitehall. He now set up the Joint Committee's Tax Group and, working with Michael Saunders Watson late into the night at Westminster month after month, he persuaded sceptical Labour MPs, long before Thatcherism, that the only practical way to preserve these historic buildings was to leave them in the private sector, and exempting them, their contents and their surrounding land from the new taxes.
This success contributed to the rapid growth of the Historic Houses Association. Benson went on to play a key parliamentary role in the birth in 1983 of English Heritage and, 10 years later, of the National Heritage Lottery Fund. He founded English Heritage's Gardens Committee, urged the creation of the Register of Parks and Gardens, and chaired the committee helping with repair of damage after the 1987 hurricane.
He served on the councils of many conservation organisations, including the Society for the Preservation of Ancient Buildings, the Georgian Group, the Westonbirt Advisory Committee, the Old Chiswick Protection Society, and the Friends of Chiswick House. From 1974 to 1984 he was a member of the Historic Buildings Council, and in 1983 was appointed a Commissioner of English Heritage.
His selfless enthusiasm and industry, and his charm and humour which encouraged colleagues to work in the common cause, were of great service to all these bodies, and many other charities, yet he still found time in private life to apply his kindness, energy and generosity to the benefit of friends and family.
Jeremy Benson was one of the three most effective lobbyists of Parliament I have known, writes Tam Dalyell.
In the 1970s, during the days and nights of the passage of the annual finance bill, at 4.30pm at the start of business, two men with briefcases would arrive in Committee Room 10 on the Committee corridor of the House of Commons, and would remain until the early hours of the following morning, if necessary. They were Commander Michael Saunders Watson, later (1982- 88) President of the Historic Houses Association and Chairman of the British Library Board from 1990 to 1993, and Jeremy Benson.
They would sit patiently through any business pertaining to the heritage, lending expertise to any MP on the committee, who would go to talk to them, or, if necessary, have notes passed from their perch on the visitors' chairs with a pertinent point to friendly members of the committee. Nor was it beneath the dignity of Treasury ministers to ask their officials to go and have a quiet word with Benson and Saunders-Watson, such was the respect in which they were held by ministers as well as MPs.
Of personal benefit to Benson there was no question. He was there from the heritage, for the heritage, and because he cared passionately about the heritage. The more favourable financial regime which the heritage now enjoys is one of Benson's memorials, along with the Cascade at Chiswick House.
Jeremy Henry Benson, architect and conservationist: born London 25 June 1925; Chairman, Georgian Group 1980-85, President 1985- 90; Commissioner, Historic Buildings and Monuments Commission (English Heritage) 1983-88, Chairman, Gardens Committee 1984-92; OBE 1984; Chairman, Society for the Preservation of Ancient Buildings 1989-90; Chairman, Old Chiswick Preservation Society 1993-99; married 1951 Patricia Stewart (two sons, three daughters); died London 1 December 1999.