However, nearly one in five also failed the checks during a month-long UK-wide Health and Safety Executive initiative at thousands of sites.
More than half of the 50 construction workers killed last year were working in the maintenance, repair or refurbishment sectors (Pictured – image courtesy of HSE).
Inspectors visited more than 3,200 sites and saw more than 4,000 contractors.
HSE’s Chief Inspector of Construction Philip White said: “It is encouraging that inspectors found a slight improvement in standards and small construction firms are taking safety seriously when carrying out refurbishment work.
“But this is just a snapshot, and the number of notices served for unsafe work at height is still unacceptable, particularly when the safety measures are well-known and straightforward to implement.
“Too many contractors continue to put their own or other people’s lives at risk and we will not hesitate to take action where standards are not met.”
The HSE says falls from height remain one of the most common causes of deaths and major injury.
It says these falls were responsible for 49% of enforcement notices, but that showed a slight improvement on previous years.
UCATT general secretary Steve Murphy said: “With so many construction sites failing to meet fundamental safety standards, it demonstrates that the HSE needs greater resources in order to ensure workplace safety for construction workers throughout the whole year.”