Prime Minister Theresa May has ordered a full public inquiry into the fire that engulfed a west London block of flats, killing at least 17 people.
The fire service does not expect to find any more survivors in Grenfell Tower, north Kensington, so the final death toll is expected to rise.
Mrs May said she had taken the decision to order an inquiry after talking with fire investigators about the way in which the fire spread.
"So it is right that, in addition to the immediate fire report that will be produced and any potential police investigation, that we do have a full public inquiry to get to the bottom of this," she added.
The Labour leader, Jeremy Corbyn, who also visited the site, said "the truth has to come out".
RIBA President Jane Duncan said: “The fire at Grenfell Tower is an awful tragedy and my thoughts are with the victims, all those affected and the heroes who responded.
“Speculation about the fire’s cause or spread, prior to a thorough investigation, would be inappropriate.
"Fire and people safety are absolutely critical in all buildings, which is why there must be an urgent public inquiry to fully understand how this tragedy occurred.”
The Association for Specialist Fire Protection (ASFP) conveyed its sincere condolences to the families of those who lost their lives in the Grenfell Tower tragedy and paid tribute to the bravery and professionalism of the fire service.
In a preparted statement it said: "The incident highlights a number of concerns regarding fire safety in the built environment and demonstrates how vigilant we must all be when designing, supplying and installing fire protection in buildings.
"Compartmentation and structural fire protection play a vital role in protecting escape routes and slowing the spread of fire and smoke. But there can be tragic consequences which may ensue if such systems are not adequately specified, installed and maintained; or are bypassed by rapid fire spread outside the building as may have happened at Grenfell House.
"Working with stakeholders from across the entire construction industry, the ASFP has been leading an initiative to ensure that fire protection is considered throughout the life of a building from design, through construction and fit-out to the building once in occupation.
"The ASFP is developing an overarching Construction Strategy to encourage collaborative working across the whole design and build process to improve the quality of installed fire protection within the built environment. Key to this is introducing fire protection into the Royal Institute of British Architects (RIBA) Plan of Works to ensure that there is a detailed specification for fire protection in initial building designs, and throughout the construction process. This aims to ensure that fire protection measures are correctly designed, specified, installed and inspected to make buildings safer for everyone."
David Orr, Chief Executive at the National Housing Federation, said: “We have been following developments very closely since the appalling fire at Grenfell Tower in the early hours of Wednesday morning.
"We are deeply saddened by the scale of the devastation and our first thoughts have been and still are with everyone who has been affected by the tragedy. We have also been overwhelmed by the tremendous work and determination of the emergency services and are deeply grateful for everything they have done.
“London-based housing associations have been quick to offer emergency accommodation, supplies and voluntary help from experienced staff.
“We at the Federation have been focused on coordinating these efforts between our members and Kensington & Chelsea Borough Council. We are also collecting information on the action our individual members are taking and working closely with the Department for Communities and Local Government and the Housing Minister.
“Housing associations across the country have been working tirelessly over the past few days to reassure tenants. Many are reviewing their current safety arrangements to ensure they meet the highest possible standards.”
