Architect, planner and tireless battler on behalf of the underdog

The architect and planner Brian Anson, who has died of a heart attack aged 74, was tireless in his battles for the rights of those whose problems others overlooked or thought insurmountable. He was driven by a profound understanding of, and sympathy for, the underdog.

Brian will be remembered for his role in the fight for Covent Garden in the late 1960s. He lost his job at the Greater London council as a result of siding with local residents against the council's plans to tear down the historic buildings and install a monstrous, car-dominated redevelopment after the relocation of the fruit and vegetable market to Nine Elms in south-west London. It was an epic battle between developer and citizen, a pattern then occurring across Europe, but Brian and a group of friends prevailed against the odds. Had they lost, London today would be a less humane and beautiful city.

Small in stature, but wiry, resilient and endowed with talents that grew over time, Brian was a wonderful wordsmith, a considerable artist, a beautiful draughtsman and a true raconteur and revolutionary.

He was born and brought up in Bootle, the docklands area of north Liverpool. It was a tough area in tough times, yet Brian saw how humour and solidarity kept the community together. He was educated at Bootle grammar school and went on to study architecture at Manchester University. He worked as an architect and planner in Liverpool and Dublin in the mid-60s, then arrived at the Greater London council in 1967 as a deputy principal planner for the Covent Garden design team. He later recorded his efforts to save Covent Garden in the book I'll Fight You for It, published in 1981.

I was first introduced to Brian at the Architectural Association School of Architecture (AA), where he was a teacher from 1972 to 1980. Alan Boyarsky, then principal of the AA, asked me to review the work of a couple of their fifth-year students, whose class was being taught by Brian. The students, dubbed "the cabbage patch unit", had been working on a project about planning allotments and the AA was concerned that their work could be seen as inappropriate training for a career designing buildings.

In the end, the students passed, not least thanks to Brian's commitment to their avant-garde approach. Nobody who knew Brian would have been surprised by this. He had always valued forward thinking and activism, and focused his considerable energy on creating an awareness of the difficulties faced by disadvantaged communities.

When Brian was teaching at the AA, he started an architectural unit to deal specifically with derelict areas and their socially excluded inhabitants. His unit at the AA covered a wide variety of projects, including successful campaigns to halt major redevelopment in Ealing, west London, and the village of Bridgtown in Staffordshire. The unit ran a study into the decline of the industry and villages of the Colne valley in West Yorkshire and another in the Afan valley in south Wales, looking at such issues as healthcare and community hospitals, leisure provision, employment and housing.

He became a dynamic force on the Architects Revolutionary Council (ARC), a movement dedicated to community architecture, from 1973, and the Schools of Architecture Council (SAC), a forum for open debate among architecture students, in 1979. His commitment to empowerment was also reflected in his work for Planning Aid in the early 1980s, when he toured Ireland and the UK in the "mobile planning aid unit", a converted VW caravanette, offering consultation and planning assistance.

During this period, he became closely involved in supporting the rights of those living in the Divis Street flats, a grim housing estate in Belfast where the British army had constructed an observation post on the roof and occupied the top two floors. "In all my community struggles, I have never seen anything like it," Brian wrote to me at the time. "The residents asked me to help in their crusade to demolish the place. We found ourselves taking on the British government ... and we beat them after five years."

Ten years ago, the battle to conserve the Hoxton Square area in east London finally got to Brian. He sensed a bitter avarice there – it was not difficult to understand why, when Old Street was all that separated the rundown and depressed area of Hoxton from the richest square mile on the planet.

Semi-retirement in France beckoned, but his sense of justice still drove him on. The socialist element of the French architectural establishment adopted him as one of their own, and he would occasionally give one of his remarkable lectures at their behest. I remember one in particular at the Venice Biennale and another at the Sorbonne.

From 2001, Brian revisited the UK every year to teach at Birmingham University. The module on community involvement that he ran there, with his great friend Mike Beazley, focused on unlocking and sharing the deep understanding that students had about their own communities.

A great friend, leader and teacher, Brian was one of a tiny handful of heroes I have had the good fortune to know. We exchanged letters regularly over the years – he was a marvellous correspondent – about everything from political horrors to daily life, and I shall miss the long conversations over many a beer in dark pubs, discussing the ways of the world and plotting the next revolution. Brian taught me to understand those who suffer indignities at the hands of our society.

At the end of his life, he shared a small cottage in the Dordogne with his wonderful wife, Mary. He talked constantly about what a tower of strength she had been, and about his children, of whom he was very proud.

He is survived by Mary and their sons Conn and Finn. Two daughters, Niamh and Mary, predeceased him.

• Brian Anson, architect, born 26 March 1935; died 22 November 2009