"We were aware that so many projects fail and never get off the ground," said Jonathan Guthrie, Edinburgh council's partnership director who created the 'string of pearls' concept.
"We wanted the development sites established first."
Each site will combine both heritage and shopping attractions, and so draw visitor, tourists and shoppers along the city.
So far, only the Castle Street pedestrianisation is complete, but the St Andrew Square World Heritage Site is next. Covered walkways will eventually also link Princes Street and George Street, and development proposals that involve demolishing non-listed buildings will be 'encouraged'.
"Every block will have heritage, historical and commercial value," said Guthrie. "We wanted to protect heritage, create commercial opportunities and deliver major regeneration."
Designs are not yet final, and the city centre is looking for development partners.