Plans for a new £23 million "super-school" in Machynlleth, Powys have been unveiled.
Ysgol Bro Hyddgen would provide education for about 620 pupils from primary age through to sixth form in the Dyfi Valley.
The scheme is yet to get planning permission but could open in 2020.
Cabinet member for learning Myfanwy Alexander said it would "secure the future of both education and the Welsh language in the Dyfi Valley".
The proposals were put on show at an exhibition attended by the public, council representatives, contractors Dawnus and architects Architype.
It would be the county's first school - and just the fifth in Wales - with the Passivhaus accreditation designed to cut CO2 emissions.
Plans also include sports facilities and a 3G sports pitch which would be open for community use.
Under the scheme, the current secondary would remain open with the new school being built on the playing fields alongside, before the old building was demolished.
Consultation on the plans closes on 19 November.