Techniquest has submitted a planning application for a £5.7m project which would expand its science discovery centre in Cardiff Bay.
The application - which would increase the exhibition floor space by 60% - includes a designated community space overlooking the bay, a new café and shop, a roof terrace and a courtyard.
It is anticipated the build would also increase visitor numbers by 40%.
If approved, work would begin in Spring 2019.
The additional 900m2 of exhibition floor space would house innovative content related to, and developed with, Welsh STEM innovators, academics and communities.
Lesley Kirkpatrick, CEO of Techniquest, said: "Since securing funding, it has been full steam ahead in our Science Capital project. We've been working closely with our consultants to marry up our objectives, with the space we have available, and our ultimate goal of ensuring the charity has a sustainable and long-term future in Wales.
"We're delighted with the final plans, which are contemporary, inclusive, flexible and eye-catching. Gaining planning consent is naturally a crucial factor in the future of this project so we're hopeful for a positive result."