The application for two new buildings has been submitted by the Bumford family of Rhosfawr Uchaf, Cyfronydd to Powys County Council.
It would bring the total of chickens reared at the farm near Llanfair Caereinion for meat to 114,000.
Back in 2018, the family were given permission for an initial poultry unit for 38,000 chickens.
Agent Richard Corbett, of Roger Parry and Partners, explained the proposal in a design and access statement.
Mr Corbett said: “The farm business has made the decision to diversify into a poultry to support their successful sheep and beef enterprises and the applicants wish to enhance the business to create a sustainable future for themselves and their young family.
According to the documents the site for the new buildings is a field next to the existing farm buildings which will allow the family to be in “sight and sound” of the buildings at all times.
Manure from the units will be spread on the land.
While Llanfair Caereinon Town Council has said it supports the proposal, Welsh Government environment body, Natural Resources Wales, has questions over potential pollution issues.
This is because Rhosfawr Uchaf is close to a number of Sites of Special Scientific Interest including the River Banwy.
Natural Resources Wales development adviser, Harriet Power said: “We have concerns with the application as submitted because inadequate information has been provided.
“To overcome these concerns, you should seek further information from the applicant regarding drainage and manure management. If this information is not provided we would object to this planning application.”
It is expected that Powys planners will decide the application by April 28.