Research published by the National Heritage Training Group showed that more people with traditional building crafts such as stonemasons, thatchers, dry stone-wallers and slate roofers were needed to be trained to retain old buildings including Buckingham Palace.
The report said that although the shortage of craft workers has eased in recent years there is still a skills and knowledge gap.
Many people working on the repair and maintenance of older properties did not have the proper skills or materials, it was claimed.
Research showed that many people were finding it hard to find joiners, roofers and carpenters, while levels of satisfaction with repair work have declined "considerably."
There are only 507 fully accredited conservation professionals in the UK from a base of half a million architects, engineers, surveyors and conservation officers, equivalent to one accredited surveyor to every 85,000 old buildings, and one engineer to every 276,000, the study showed.
ConstructionSkills chief executive Peter Lobban said: "We've taken some giant steps to ensure that more people are taking up these traditional building crafts that are so important to preserving the country's heritage buildings.
"But there is more work to do. Many of the people undertaking repair and maintenance work on pre-1919 buildings need upskilling to guarantee that tasks are completed to the highest possible standard and England's iconic and more humble buildings are not spoilt."