"extensive demand" is correct and usable in written English.
You can use it to refer to a large amount of demand for something, such as a product or service. For example, "The introduction of the new phone model created an extensive demand among consumers."
Extensive demand for housing around India's cities and pervasive corruption often result in builders adding unauthorized floors or putting up illegal buildings.
After the development of the incandescent gas mantle by Carl Auer, Baron von Welsbach, in the 1880s, thorium came into extensive demand and use, but, when electric power became generally available after 1920, worldwide utilization of thorium gas mantles sharply declined.
As a result of the extensive demand of oil for consumption and industrial uses, analysis of many oils has been carried out.
The extensive demand for a rapid, automatic, and high quality algorithm for feature extraction has been the subject of much recent research.
As a result, rationally designed nanomaterials are in extensive demand for bio-molecular detection and diagnostics, therapeutics, drug and gene delivery, fluorescent labelling, tissue engineering, biochemical sensing and other pharmaceuticals applications.
All eyes will, as such, be on Q4 and the unveiling of the iPhone 7. Apple's last blowout performance came with the launch of the iPhone 6, which finally introduced a line of larger iPhones that proved to have extensive demand.
Mr. Mottola began writing the script early last year, but because of the extensive demands of "Paul," he was several months late.
The union "presented extensive demands, some of which had been withdrawn previously, and one which had not been raised before," it said.
While Giants fans fret over their spotty defense and Jets fans bemoan Mark Sanchez's inconsistency, Barone is consumed by the extensive demands that come with keeping hundreds of oversize men looking television-ready week after week.
India's youthful population can be viewed as a double-edged sword – capable of bringing great benefit to the country in the decades ahead, but with extensive demands that, under current economic conditions, the country looks unable to fulfill.
Again, in the light of the circumstances prevailing (especially related to the extensive demands on police time in relation to terrorism), it was understandable, justified and appropriate" 3.43pm GMT Bonkers David Cameron said previously that he would implement Leveson's proposals unless they were "bonkers".
