The interim report did not attribute blame for the June blaze in a residential block, which killed 71 people, but said the rules for ensuring fire safety in such high-rise buildings made it too easy to "cut corners".
"The mindset of doing things as cheaply as possible and passing on responsibility for problems and shortcomings to others must stop," wrote author Judith Hackitt, a former health and safety executive.
She said she had been "shocked" at some things she had discovered, concluding: "The current regulatory system for ensuring fire safety in high-rise and complex buildings is not fit for purpose."
A public inquiry is under way into the causes of the Grenfell fire, with questions focused on whether a recent refurbishment -- including the fitting of external cladding -- may have fuelled the blaze.
The fire started in the early hours of June 14 with a faulty refrigerator on the fourth floor of the local authority-owned building, but rapidly spread up the 24-storey tower.
In the wake of the tragedy, hundreds of similar buildings across Britain were subjected to safety checks, and some residents were evacuated as a precaution.
Hackitt stressed that her review, which will be followed by a full report published next year, did not mean that all buildings were unsafe.
But she warned regulations were too complex, there was a lack enforcement mechanisms, and said the building industry must take greater responsibility for safety.
"What is initially designed is not what is being built, and quality assurance of materials and people is seriously lacking," she said.
She also called for changes to ensure residents' concerns were heard.
The local authority with responsibility for Grenfell Tower, Kensington and Chelsea, has been criticised for failing to listen to warnings about fire safety.
As well as the public inquiry, a police investigation is under way to determine whether any criminal charges can be brought against individuals or corporate entities.
Eyewitness? Submit your stories now via social or:
Email: eyewitness@pulse.ng
![The woman was recorded, among others, while bathing [BI]](data:image/svg+xml;charset=utf8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'300'%20height%3D'172'%20data-ring-placeholder%3D'1'%3E%3C%2Fsvg%3E "The woman was recorded, among others, while bathing [BI]")
