The planning application, submitted by Mark Stenning of 13 Weirside Avenue in Wroughton, has been approved by Swindon Borough Council.
The structure is intended to house a golf simulator at the bottom of a semi-detached building in a residential area.
In a report published online, planning officers from the council said: “The overriding objective of the local planning policies are to deliver high quality development which improves the quality and distinctive identity of places and meets the housing needs of existing and future residents.
“As such, it is acknowledged that alterations to existing dwelling houses can facilitate additional and enhanced living space for improved living conditions for occupants.
“These are therefore considered acceptable in principle subject to ensuring a high-quality, neighbourly design.”
The proposed outbuilding will be located at the end of the property’s garden and will not be used as an independent residential unit.
It will have a pitched roof with a ridge height of approximately 4.4 metres, a width of 4.2 metres, and a length of 6 metres.
The building will be finished in dark grey composite cladding.
The property is a semi-detached house in a wholly residential area and already has approved planning permissions for the erection of a single storey detached annex.
Planning officers confirmed that the site is not in a conservation area, not within the setting of any listed heritage assets.
The report states: “The proposed annexe would exceed height guidance slightly; however, it would remain clearly subordinate to the host dwelling.
“When considered alongside other development on the site, including the approved and implemented annexe within the same rear garden, and other sheds and outbuildings, the proposal would not result in overdevelopment of the plot, and ample garden space would be retained.
“Owing to its position at the rear of the property, it would not materially harm the character, appearance, or composition of the street scene.”
A planning condition has been applied to ensure the outbuilding is only used for purposes incidental to the main house and is not occupied as a separate residence.
The report also addressed potential impacts on residential amenity.
Officers said: “The proposal would not give rise to any undue harm to the amenity of neighbouring occupants.
“By virtue of its location, design and scale, it would not result in any unacceptable loss of light or overshadowing and would not be domineering.
“There would be no resultant overlooking or loss of privacy.”
Wroughton & Wichelstowe Parish Council raised no objections to the scheme.