"considerable extension" is correct and usable in written English.
You can use it when referring to a significant amount of time or distance. For example, "The proposed bridge will need a considerable extension to span the river."
On the contrary, the UK, because of the need to find extensive evidence about supermax prisons, asked for a considerable extension of time to submit information.
Shirk, however, received considerable extension of meaning throughout the dogmatic development of Islām.
Marketization can require a considerable extension and use of government power.
Gove's position as chief whip, working with his new deputy and fellow Osborne ally Greg Hands, marks a considerable extension of the chancellor's power base.
During the troubled 1930s, however, Horthy assumed more and more control, and in 1937 the Parliament voted a considerable extension of his powers.
So here as artist-in-residence he promises to infiltrate the Long Gallery with a work-in-progress scaffolding of TV monitors, record players and strip lighting titled A Considerable Extension In Time And An Insignificant Extension in Space.
During those years and indeed until his death, Carnap was occupied principally with modifications and considerable extensions of his inductive logic.
In addition, the cells migrated into the microchannels (2 mm) with considerable neurite extension.
Introducing artificial closure material into a fatigue crack has been shown to be able to retard the crack and give considerable life extension.
However, due to the considerable southward extension of the sea during the Eemian and presumably also during the Holsteinian, buried interglacial river deposits in central Poland occur at present well beneath the Holocene alluvia.
This proposed view of how to consider gene expression (or similarly peptide/metabolite abundance) in a genetical context is currently receiving considerable attention, extension and refinement of methodology [ 21- 25].
