This blog relates to sale/purchase transactions, its common for developers to get planning consent before purchasing.
Just getting planning consent doesn’t trigger a change, its the use at the effective date of the transaction that overrides any past or intended future uses for the property.
The Rules are in
http://www.legislation.gov.uk/ukpga/2003/14/section/116
Meaning of “residential property”
(1)In this Part “residential property” means—
(a)a building that is used or suitable for use as a dwelling, or is in the process of being constructed or adapted for such use
http://www.legislation.gov.uk/ukpga/1994/23/schedule/8/part/II/chapter/5/paragraph/2
a building designed as a dwelling or number of dwellings or intended for use solely for a relevant residential purpose
https://www.gov.uk/hmrc-internal-manuals/stamp-duty-land-tax-manual/sdltm20076
In most cases, there will be no difficulty in establishing whether or not a property is residential property.
Use at the effective date of the transaction overrides any past or intended future uses for this purpose.