For all Joomla 3+ templates built using the Zen Grid Framework v4 (any theme after October 2014) please refer to the Zen Grid Framework v4 documentation.
The template contents document will give you a good idea of whats required to create a zen grid framework compatible template and as an example template we have two blank templates available for you to use as a base template.
The Zen Blank and Zen Default are the perfect starter template to use with the framework as they contain all of the files required to use the Zen Grid Framework but come with only a minimal amount of styling. This means that you get almost a blank slate to start with without sacrificing the power and the flexibility of the core Framework. Put simply you can create a powerful joomla template by only editing css without the need to get your hands dirty with needing to know php and even html.
You can download these two templates from the Zen Grid Framework download page.