The company said troubles in the financial sector had left sites once earmarked for office and residential development now available for other uses.
The new sites include office block conversions in Preston and Doncaster and projects in two London locations – Greenwich and Aldgate.
The announcement comes a week after the firm announced it was to acquire 21 hotels, currently operating as Express by Holiday Inn, from hospitality company Mitchells & Butlers. It plans to re-brand the sites under the Premier Inn logo.
Whitbread Hotels & Restaurants property director Mark Anderson said: “Our property acquisitions team is identifying prime sites for development across the UK and Ireland as we roll out our expansion plans.
“We have disciplined targets for growth and these investments demonstrate that we are well on our way to delivering them.”
Other projects include a 60-room hotel and restaurant in Glasgow, another in Trowbridge and a 55-room hotel in Newport.