Meanwhile, the average grant value has increased from $814 to $1154 over this time period.
The increases in Wellington were in line with national trends until the middle of last year when the capital experienced a spike in both the number and cost of emergency housing grants.
The latest TradeMe figures put Wellington as the most expensive urban centre to rent in.
That tightening squeeze on the rental market was leading to the increase in emergency housing grants and their cost, Salvation Army Central Division community ministries secretary Major Pam Waugh said.
People were struggling to get back into the rental market if they had been forced out, she said.
"People are having to become much more innovative in how they attract a landlord to take them on, so therefore the people who are further down the rank and don't have all the resources are missing out."
She said she knew of a mother who had spent more than a year in a motel with four teenagers.
"Can you imagine the cramped conditions, you've got teenagers who've been trying to study towards the end of the year for exams, you've got limited facilities."
"That makes a huge difference to her confidence when she goes out to try and look for housing. When it comes across as who you are, what you have to offer against other people who may have a couple of people in jobs and a lot more resources, those people are getting a look in first."
But even people who have jobs were finding it hard as the crisis extended to the middle class, she said.
These trials and tribulations of Wellington City's rental prices are affecting the entire region.
As it becomes more expensive to buy and rent, people are being pushed out to the capital's satellite cities. That's contributing to shocking figures like Lower Hutt's social housing wait list jumping 42 per cent in just one month.
Ministry of Social Development general housing manager Karen Hocking said the supply of affordable accommodation was tight across the country with Wellington City being no exception.
"As the housing shortage continues, we are helping growing numbers of people with emergency accommodation in Wellington.
"While there has been a growth in the number of emergency accommodation special need grants in Wellington City, the average grant in the capital is still lower than the National average."
Wellington based National list MP Nicola Willis said the Emergency Housing Grant data was shocking but reflected a desperate need.
"It's very scary for the people in these situations because this is very unstable housing, these are families living in motels, this is not an arrangement anyone would want in the long term.
"And what they actually want is a permanent home with a roof over their head. Seeing these numbers increasing so fast tells us there's a desperate lack of permanent housing available in Wellington."
