The Government is being urged to bring in tougher safety regulations for what are being dubbed rented "firetraps".
The housing organisation, Threshold, says local authorities need more resources to carry out fire safety inspections.
It says the current rules do not even require landlords to provide smoke detectors, emergency escapes or modern heaters and cookers.
The group say it is particularly worried about the risks posed by older rented properties, which often have barred windows.