Synagogues up and down the country are more at risk than ever, according to EH's Jewish Heritage in Englandpublication.
The guidebook - which was drawn up with organisation Jewish Heritage UK - is the quango's first comprehensive survey of Britain's Jewish architecture.
EH said the problems are worsening mainly due to demographics. Britain's Jewish population has shrunk by nearly half nationally since the 1950s, and congregations have moved away from urban centres, leaving some of the country's most spectacular religious architecture in danger.
The full-colour guidebook describes more than 300 Jewish buildings throughout the country. Among those reported to be in trouble is the Grade II*-listed Montefiore Synagogue in Ramsgate, Kent ( pictured). Current redevelopment proposals in the pipeline look set to threaten the site's integrity.
Andy Brown, EH's planning and development director for the South East, said: 'The guidebook Jewish Heritage in Englandplays an important role in showing for the first time the magnificent contribution Jewish architecture has made to the nation's heritage.'