Three Victorian hotels will go to make way for a six-storey, four star hotel and two assisted-living apartment blocks, at East Cliff in Bournemouth.
English Heritage strongly objected to the scale of the development in what is a designated conservation area.
But, councillors voted seven to three in favour saying it would help tourism.
Chair of the planning board and Conservative ward councillor David Kelsey, said the buildings earmarked for demolition were nice but no longer "necessarily functional".
"They've come to the end of their working lives, we need to preserve the tourism aspect while improving living for older people in the town," he said.
"The loss of buildings and trees are always regrettable but we can't stand still, we need to move forward."
The site on Grove Road and East Overcliff Drive will get a 90-room hotel along with a nine-storey and seven-storey building, comprising 122 assisted-living apartments.
Applicants The East Cliff Project LLP will demolish Bay View Court, The Cottonwood and the Ocean View hotels.
The council received 246 letters supporting the plans.
Forty-nine residents and the Ancient Monuments Society wrote to object to the demolition, stating that despite being altered, they still "give a sense of the historic character of the area".
English Heritage said the scale of the development would cause "severe harm" to the conservation area.

The singer's shared the video for Living for Love, the album's first single, on the new Snap Channel alongside a behind-the-scenes clip from the video shoot.
It all follows a leak of the star's 13th studio album ahead of its planned release on 10 March. This is the first music video to be published since the launch of SnapChat's "Discover" service.
We were hoping it might look like this...
But it all looked a bit more like this...
Snapchat has partnered with media companies to feature videos and news articles on the app.
After 24 hours the stories disappear, in keeping with Snapchat's trademark feature of private messages that vanish a few seconds after being viewed by users.
Snapchat, which reportedly turned down a $3bn (Â£1.2bn) buyout offer from Facebook, has been valued at around $10bn (Â£6.2bn).
Madonna is set to perform at the Grammys on 8 February and at the Brit Awards on 25 February.
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The 35-year-old centre-half will be banned for two games because it was his second dismissal of the season.
That rules him out of Chelsea's final two Premier League fixtures, against Liverpool and champions Leicester.
"It's sad, it would have been lovely to have had him in our last game at home," said Chelsea manager Gus Hiddink.
Terry is out of contract at the end of the season and has not been offered a new deal at Stamford Bridge.
"It's sad, of course, that he was sent off for a second yellow, and it's the second sending-off, which by the rules means he will be suspended (for both games)," Hiddink added.
"I think he (referee Mike Jones) was too close and an impulsive reaction made him draw the yellow card.
"He was too close, for me, and took too harsh a decision."
The former England captain joined Chelsea at the age of 14, made his senior debut at 17 and has won a host of honours with the club, including the Champions League, four Premier League titles and five FA Cups.
But, after 483 Premier League appearances in the past 18 years, he could now have played his last game for Chelsea.
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A hotel and apartment complex in Dorset has been approved despite English Heritage stating it would be a "hammer-blow" to the area.
[NEXT_CONCEPT]
Madonna premieres the first music video from her new album, Rebel Heart, on Snapchat.
[NEXT_CONCEPT]
Chelsea captain John Terry will miss the rest of the season through suspension after his red card in Saturday's 3-2 defeat at Sunderland.