Hot on the heels of his triumphant US Masters win, the champion golfer switched his attention from Augusta's hallowed greens to the greenbelt surrounding his lavish Surrey home on greenbelt land, securing 'very special' approval for modifications to have a pool installed.

Basking in the glory of sealing an epic career grand slam in his iconic green jacket, McIlroy has succeeded in getting permission to fit a modern heat pump within his plush Wentworth Estate grounds.

The installation, intended for a newly planned outdoor swimming pool, had been tagged as 'inappropriate' under standard national planning rules.

However, Runnymede Council's planners have sanctioned the proposals with specific conditions attached, conceding: "The development is considered to be inappropriate development within the Green Belt, but very special circumstances are considered to exist."

The council admitted the applicant proved the environmental merits of the pump by showing it would utilise renewable energy sources to warm the pool.

In their official decision notice, the authorities pointed out: "The harm identified in the above assessment is that the proposed development constitutes inappropriate development within the Green Belt, this is given substantial weight.

"The Green Belt balancing exercise therefore needs to be if 'other considerations' put forward as part of this planning application equate to Very Special Circumstances which exists to outweigh the harm and any other harm.

"This harm includes the inappropriate development in the Green Belt and the impact on openness."

McIlroy's team submitted an application arguing that 'very special circumstances' existed due to the "wider environmental benefits" of a heat pump providing "renewable energy" for the proposed pool's heating.

The planners concurred, stating in their decision notice: "It is considered that significant weight can be attributed to the environmental benefits and this would outweigh the harm to the Green Belt.

"It is considered that very special circumstances exist."

The £9M mansion is characterised in planning documents as a "large, detached dwelling sited centrally within a substantive plot."

Previously, the golfer was granted planning permission for a dining and utility room extension, a new roof and internal alterations.

Last year, he also received approval for an outdoor pool, play centre and 5ft-high water feature wall.

Council planners noted that the site "as a whole is currently under construction after the approval of recent permissions."

However, the latest application sought planning permission to install an air source heat pump for the outdoor pool and construct a timber enclosure.

McIlroy's planning agent wrote: "The heat pump is located towards the southern boundary of the site.

"The heat pump is a single unit enclosed by a 1.8 metre high timber enclosure. The heat pump requires permission in view of the fact that the site already has heat pumps located towards the northern boundary."

They further stated: "The provision of renewable energy, limits the requirement for the use of non renewable energy sources. .

"The wider environmental benefits associated with increased production of energy from renewable sources using the (heat pump) constitutes a "very special circumstance" which justifies the (heat pump) in the Green Belt."