The application was made by Mills Ltd for land east of the B4395 road at Llangadfan.
The company already has a chicken farm in the village, and this will expand its operations there.
Banwy Community Council supported the application when it discussed it in November 2019, but several residents objected to the proposal.
Powys County Council planning officer Holly Wilkinson said in her report: “Having carefully considered the details submitted, together with all statutory consultee responses and third party representations, officers are satisfied that the proposed development complies with the relevant policies.
“As such, the recommendation is one of conditional consent.”
In her report, Ms Wilkinson added that she did not “consider” that spreading manure on the farm will have a bad effect on the environment or people living nearby.
She added that excess manure will be taken to anaerobic digester (AD) plants, which can turn manure into energy or fertiliser.
Documents with the application show that Mills Ltd have already received an Integration Pollution Prevention and Control (IPPC) permit from Natural Resources Wales (NRW) for 250,000 birds.
Broiler chickens are birds reared for their meat.
The design and access statement (DAS) that accompanies the proposal said the application was “future proofing the site”.
The birds will be in the the units for 42 days, and it’s estimated there would be seven to eight cycles a year.
The DAS continues: “The proposal amounts to sustainable development that will improve the agricultural business on site.”
In recent months, opponents of chicken farms in Powys have wanted to see a pause on these types of development so that research can be done into the effects they have on the environment.
A spokesman for the Campaign for the Protection of Rural Wales (CPRW) said: “It is not clear to us that the cumulative impact of the proposal has been fully considered.”
A Freedom of Information (FOI) request by the Local Democracy Reporting Service asked all planning authorities in Wales how many planning applications for intensive poultry units had been received between April 1, 2017 and April 1, 2020 and what happened to them.
The data showed that in that time Powys had received 96 applications, of which 75 were approved, and three were refused.
To compare, planning authorities across the rest of Wales received 20 applications, of which 13 were approved, two were refused, and one withdrawn.