Jacob Harb, head of electric vehicle operations and strategy for BMW, talked to AutoblogGreen at the 2014 Detroit Auto Show on the next steps for the i sub-brand. Without directly confirming any future products, Hard hinted that a midsize “i” model is in works.

“You can probably take an educated guess at the next thought process, something a little bigger, maybe a little more range, relative to the i3. We’ve got everything trademarked and we’re exploring the best, next iteration. It is coming. It’s in development now.” An i5 has been rumored last year and Harb said he’s flying to Munich next week to “start the discussions further” on BMW’s next-generation electric vehicles.

The BMW i5 is rumored to be more family friendly, with extra cabin and trunk space. BMW engineers think that by adding just 100mm of extra legroom and another 150mm of rear overhang, they can create a spacious family EV hardly longer than a MINI Countryman.

Creating the i5 is potentially a much cheaper and simpler operation than stretching a conventional steel monocoque car, as the i3 uses a separate chassis. Lengthening it is mostly a matter of extending the chassis’s longitudinal aluminum extrusions. Also extending the pillarless passenger cell is mainly a case of stretching the roof and floor sections. Only the rear door structure would have to be completely re-engineered, although the hinge and clamp systems would be unchanged.

BMW i5 will debut in 2015.