Foundation work for the first tower has started following the completion of Saudi Oger's excavation work for the project, which began in March 2008.
The 15 towers will range between 22 and 26 floors.
The $2.7bn project is being developed by the Jabal Omar Development Company and is being constructed by a joint venture of Saudi Binladin Group and Saudi Oger.
Jabal Omar’s masterplan covers 1 million square metres and includes the construction of six five-star hotels, and when complete will accommodate up to 40,000 residents.
It is just one of a number of major developments that are transforming the city.
Other major projects include the Abraj al-Bait, a 577 metre-high building being developed by Saudi Binladin, and the Rawabi Abraj al-Bait project planned by Jiwar Real Estate (MEED 10:6:08).