Six Nations 2017: Closed stadium roof gives Wales 'advantage'
Six Nations chief executive John Feehan says Wales have been denied closing the Principality Stadium roof during the tournament in the belief that it gives them an advantage.
Wales asked organisers for permission to play all their home games under the tournament's only retractable roof but were turned down.
"They approached us, but that obviously wasn't acceptable to all the other unions," said Feehan.
"We run the competition by consensus."
The roof could still be closed for Wales' home matches against England and Ireland but would need permission from the away sides.
"What we are doing is staying with existing protocols, which basically say if both teams agree conditions demand they want to close the roof, or both teams want to close the roof anyway, that's fine," Feehan told BBC Radio Wales' Jason Mohammad show.
"But what we can't do is allow any one individual team an inherent or underlying advantage.
"The other unions perceive it to be an advantage for Wales given they could play all their games under the roof given they understand it (the conditions).
"These games are won on any tight margins anyway. It's a case of everyone wanting a level playing pitch."
Feehan said rugby union is a sport that should take place in "different weather conditions", adding: "It's not necessarily always going to be a sunny day like you would like it to be.
"Sometimes the weather conditions can have an effect on the game and that's not necessarily a bad thing.""
Listen to the John Feehan interview on BBC Radio Wales' Jason Mohammad show on Monday, 30 January from 09:00 GMT.