Tauranga architect Mark Wassung is doing the numbers to see if his concept for shared central city high rise living stacks up.

He's got his eye on the former TV3 site in Durham Street and thinks a unique mixed use senior/student accommodation high rise makes more economic sense than a hotel.

The city council owned site has for some years been marketed as a high rise hotel site, but while there have been several lookers, there have been no takers.

Mark's got a couple of developers interested and has pitched the idea for a mixed senior/student high rise accommodation to Mayor Greg Brownless and deputy mayor Kelvin Clout. And he's got 12,000 views since the posted the idea on Facebook on Friday night.

'I'm doing the numbers and the work at the moment to try and make it a real winner for the city,” says Mark. 'I'm trying to rejuvenate the city and excite it and ignite it.

'What I'm trying to do with Greg Brownless is I'm looking at international models. There's plenty of precedent around the world if you just go and search for this, where councils are actually trying to help kick start cities and have this urban renewal.

'I'm suggesting maybe council could be a partner in it, I'm not expecting anything for nothing.”

The council's hotel dream is very hard to make work, according to one of his architectural clients.

'They actually do fail a lot of them, unless you have a big operator like Hilton - and I have heard Hilton is interested here, but nothing is conclusive and one of my clients has tried it and it couldn't work as a hotel.

'I said that to Greg as well. I'm aware of these other proposals and they just don't stack up because of occupancy.”

Mark is proposing ‘twodios' two bedroomed 30m2 units, with separate ensuites and a shared kitchen.

'What I'm proposing is to do units so people are attracted; high insulation, high studs, decks to take advantage of the best views in the city. At the Bongard centre the students have the best views in town.

'I mean isn't it sad. It is so crazy that we are not taking advantage of our visual amenity.”

The next step is to see if he can sell the units.

'We need to bring people into the city to inject life into it,” says Mark.

The idea came to him a few weeks ago while having coffee in town and he looked across the city skyline.

'This city, the pending renaissance it's going to go through with the CBD, it really needs people in it. The only thing we have got at the moment is the student hostel block and I understand they are quite small units, 10-15m2, so they are fairly small and meagre and we are going to shoehorn something like 400 students in.”

The idea to mix students and seniors in the same building came from recent contact with Carole Gordon from Supa NZ and the surprise results from the Art Gallery's recent paradox exhibition.

There were 49,000 visitors in three months with customer surveys showing they were mostly in their 70s, 80s and 90s, says Mark.

The unprecedented queues to get into the gallery were like a red flag, and provided the original inspiration for a residential style that keeps seniors engaged.

'Carole tell me a lot of the retirees are disengaged and they are isolated. And that's when the rot sets in. People start to die and fall away. We have got a city campus coming in, why don't we connect students and seniors.

'We are going to go through a tsunami of retirees and a lot of them are more active than previously. They are people are upwardly mobile so they can bike, and they can go to the gym, they can walk, they are more ambulatory.”

The twodio space would be a place to stay overnight. With good thermal and acoustic insulation the generations could be mixed on the same floors or there could be student and senior floors.