The Sustainabuilt land is flat and slightly sloping, with views across the Tasman Sea and city, co-owner Glenda Brown said.
It will eventually have 40 sections of varying sizes, and all the houses will be energy efficient.
They will be built by Simon Penn, who bought Baden Brown's building business in December 2014 and is the only builder licenced to build energy efficient "passive houses" in Whanganui District.
"Everybody will have their own ideas about what they want. We are committed to making [the houses] energy efficient and we are hoping that a lot of people will want them to be passive houses," Brown said.
All the houses will meet standards higher than the current building code.
The owners want the subdivision to have a "community feel", with green spaces. Graphic designers are working on layout now.
Preparatory earthworks will begin late this year or early next year, Brown said. The company is still working on the necessary consents and a cultural impact assessment.
The land has huge historic value to Iwi, Brown said.
"We can't be doing anything but honour that."
The owners are working closely with Iwi, and have had many hui.
The company is also negotiating with council and Waka Kotahi NZ Transport Agency about the subdivision's access and intersection with SH3.
Registrations of interest for house and land packages opened in March, and there have been "lots", Brown said.
The Browns are also involved with Jon Iliffe in eHaus, a business that designs and builds passive houses all over New Zealand.