James Corden has joked that Buckingham Palace "doesn't look too shabby" despite the Queen maybe having to move out to allow the historic building to be refurbished.
The TV funnyman was in the Palace collecting his OBE from the Princess Royal for services to drama - which he said was "overwhelming" - when he made the remark.
Corden, 36, has cracked America and now lives in Los Angeles where he presents The Late Late Show on CBS, and says the architecture is what he misses most about home.
Asked if he thinks the Queen should consider a temporary relocation to LA if she does have to move out, he joked: "Oh I don't know. I think she's got some other properties.
"I mean, I'll be honest, the bits I've seen - it doesn't look too shabby.
"It looks alright to me. I mean, it's an amazing ... it's an incredible building."
It was revealed this week that Buckingham Palace needs a total overhaul and the monarch vacating the building while the work is carried out is one option being considered by Palace officials. The initial estimated cost for the refurbishment is £150 million.
Meanwhile, Corden - whose chat show has a regular feature called Carpool Karaoke in which he drives around with celebrities chatting and singing - said he would be happy for any member of the royal family to join him, but he might opt for Prince Harry if he had to pick one.
"It's got to be Harry hasn't it? He's welcome to do a Carpool.
"In fact, I can absolutely say that any member of the royal family, should they wish to, the invitation will always be there to do a Carpool Karaoke.
"I don't imagine they'll take me up on it, but should they ever wish they are all welcome, yes," he said.
Corden has participated in Carpool Karaoke with stars including Justin Bieber and Mariah Carey for his talk show.
The comic and actor said that to receive an OBE is "wonderful", adding: "It's overwhelming to come back from Los Angeles and then be stood in Buckingham Palace receiving such a thing.
"I feel very undeserved but grateful nonetheless."
Corden said he has felt lucky his whole life to have loving, supportive parents and wonderful sisters.
He said he is "very proud" of how his career has gone and how it is going, and hopes he can carry on and "keep trying to get better".
Corden said he is really enjoying life in LA but it reminds him how lucky people are in Britain to have "so much incredible architecture".
Referring to London, he said: "You'll always be rewarded if you just look up.
"And America is such a young country by comparison. And I'm surprised how much I've enjoyed ... I've been back two days and seeing the buildings and architecture ... I've really enjoyed seeing.
"And I didn't realise quite how much I'd miss that."
Corden said he felt "so nervous" about the talk show but he "couldn't have wished for a greater reception".
He said all his guests - including Tom Hanks - have been "fantastic".
Today's investiture ceremony was the biggest of the year so far, involving 102 recipients and 320 guests. Among them was former Liberal Democrat leader Lord Ashdown who became a Companion of Honour and television presenter and campaigner Esther Rantzen who was made a Dame.
The Companion of Honour - which was given to Lord Ashdown - is limited to just 65 people in addition to the Queen, and is awarded for services of national importance.
The current list of members includes physicist Professor Stephen Hawking, naturalist Sir David Attenborough and painter David Hockney.
Lord Ashdown, who led the Lib Dems from 1988 to 1999, was honoured for public and political service.
The 74-year-old former Royal Marine was High Representative for Bosnia and Herzegovina from 2002 to 2007 and is president of Unicef UK.
ChildLine founder Rantzen, 75, said she was "thrilled" when she was told she was to be made a Dame.
She was honoured for services to children and older people - the latter for founding The Silver Line helpline.
She has also presented a host of television programmes and has received the Royal Television Society's special judges' award for journalism.