In Colombia, it's financing a 66-storey apartment tower that developers declare will be the "first skyscraper built by ... common people". And in Melbourne, it could provide specially designed dwellings for groups of like-minded owners, such as pet lovers, elderly gays and lesbians, and weekend rockstars.
A spin-off from the concept of crowdfunding (raising money through social media, most commonly for films and other creative projects through donations), "crowdhousing" aims to build innovative and potentially more affordable housing by giving people a say in how they live. Unlike crowdfunding, crowdhousers are not donating to someone else's project, but contributing to their own.
Using this embryonic concept, Melbourne architect Ivan Rijavec has just launched an online platform called Citiniche, targeting owner-occupiers who have a vested interest in getting what they want but who don't individually have the resources to get a multi-unit project, with its economies of scale, off the ground.
The buying power of the group allows it to compete against other developers.
"It's a reaction against the crap that's out there and against every ... apartment that doesn't actually serve the person who lives in it," Rijavec says. "Instead of confining someone's lifestyle to a predetermined sense of what is average, what this does is say, 'Do it your way'. People are sick of going through apartments and getting beige on beige on beige."
On the Citiniche website, groups form around "niches" that reflect their needs or interests, such as pets or gardens. In some respects, it's like finding neighbours before moving in. Citiniche monitors the design discussions and when enough members demand similar aspects - rooftops, courtyards, pet-friendly areas - they propose potential housing projects.
Next, niche members will be invited to a workshop to discuss ideas further. They register by making a refundable deposit. Once the project receives planning approval, a place is secured with a full deposit. During the construction process, Citiniche will provide regular progress reports.
Among the niches being proposed on Citiniche's website are multi-unit developments that would cater for "gay greys", "urban greys" and "urban pet [owners]".
Rijavec says these groups are just the tip of untapped buyer markets. "I can't count the number of people who've said they've had problems with [permission to have] pets in apartments," he says.
Another growing group are older gays and lesbians who are reluctant to move into retirement homes or units that may not be gay-friendly. The first multiresidential development for the ageing gay population is being built 20 kilometres east of Ballarat in Ballan by another developer - but Rijavec says if any group had a preference for inner-city living, it would be this niche.
As ageing baby boomers, gay and straight, demand more than bingo and bowls, "crowdhousing" could create developments that might, for example, include shared spaces such as meeting rooms, roof gardens or pet-friendly courtyards so seniors could keep the family dog, and be in areas that people want to live.
Of course, these embryonic niche projects are only suggestions. Dozens have registered as "supporters" of different niches on the website.
Ideas range from the general to the specific. User "Duncan" offers the following idea for an inner-city apartment: "Everyone seems to have a band; people hate moving the equipment around. Why not provide soundproof rehearsal rooms in the basement with a booking system?"
On the page for the "urban loft" niche (proposed price: $415,000 for two bedrooms), user "bashton" suggests: "It would be so great to live in a place with original factory/industrial finishes."
Businessman Marcus Rose, 59, said he was drawn to Citiniche after a failed search for an inner-city apartment that would allow him to "phase shift" while retaining the space of his South Yarra family home.
His main requirement is a large urban garden, with lawn and trees, extending from the apartment's living space. He believes there will be enough people like him, with significant home equity, to invest in a complex of larger-than-usual apartments.
"I want a sense of being on the ground, but you're not - like a sky garden. I like views, and as the city becomes more built-up, I want to see the urban landscape, the sky, and be brought up off the ground. So how do you reconcile those things? I think you can."
But apartments he has inspected are small and sterile, and he says the response from real estate agents to his needs has been "glib". Their best suggestion is "we should develop it ourselves".
Yet as Victoria's Government Architect Geoffrey London points out, Citiniche and other "crowd architecture" groups could allow ordinary people to effectively develop their own townhouses or apartments. (It's easy for owner-occupiers to commission a house, but not a multi-unit dwelling.)
London describes Citiniche as a "cracker of an idea" - a kind of "housing dating bureau" that "allows people to get together and use their own resources in such a way that there is no single entity that is taking the risk".
"It's going to introduce a degree of diversity of housing types in the marketplace, a degree of choice for buyers in the medium-density sphere, and it's going to bring good design into the marketplace, where in many respects it doesn't really exist."
It's of course impossible to tell how committed the potential owners who have registered on the Citiniche site are, but the idea is taking root.
Internationally, crowd architecture concepts include Colombia's 66-storey BD Bacata apartment tower, which is under construction and which developers claim has helped poorer people buy apartments.
In Rotterdam, the attractive timber Luchtsingel pedestrian bridge is being realised through crowdfunding. The first phase has already been built, but the bridge's slogan - "the more you donate, the longer the bridge", keeps the money flowing. Donors are also promised their name engraved in large letters on one of the bridge's thousand planks.
Another similar example is New York's Lowline, an underground version of the hit urban park project the Highline, which used Kickstarter to help fund a public park in a disused subway station.
Unlike Lowline and the Rotterdam bridge project, Citiniche projects are not benevolent, but encourage online contributors to collaborate to buy something for themselves.
Rijavec says his company will focus on developments in Victoria first, although the project is fundamentally "borderless" and he has approached architects and developers in Sydney, Perth and Adelaide.
Citiniche also intends to avoid one of the major pitfalls of international crowdsourcing design site Arcbazar. Under the Arcbazar model, a client writes a brief, posts it online and designers around the world work on it. The client then selects its favourite design and pays the agreed fee. But the risk for designers is that, if their proposal isn't accepted, they don't get any recompense.
Citiniche intends to reduce this risk by expanding those commissioning the brief and limiting those solving the design problem. In Melbourne, it has registered architects including Jackson Clements Burrows, BKK Architects and Robert Simeoni Architects.
Tim Jackson, of Jackson Clements Burrows, says Citiniche will give developers confidence to look at new markets and housing models. "The development world becomes generic very quickly," he says.
"Everyone starts copying the most recently successful one. [Citiniche] is a way of throwing something into the mix that hopefully hasn't been thought about. Not only might it push the typology, it might also suggest areas of the city developers wouldn't normally have considered."
In a recent, celebrated example of developing an unusual residential site, James Legge, of Six Degrees Architects, transformed a contaminated brown-field site in Brunswick into a row of three-storey family townhouses with a private community park as a substitute for backyard space.
"It was a bit of a reaction to places getting smaller and smaller, and yet people still have a six-foot wall around them, so you end up with these pokey courtyards and pokey backyards that are not that usable and the outlook's not that great," says Legge, who also lives in the development with his family. (Friends and friends-of-friends also bought in, with prices around the $800,000 mark.) "I'd spent a formative period in England and the commons idea appealed to me," he says.
The townhouses are set back from Heller Street with a park open to the entire neighbourhood in between. In the give-and-take between private and public space, each house has a patio at the front while the undulating park landscape provides privacy.
Residents include Sally Thomas and her partner, artist Matthew Sleeth, who wanted to live in Brunswick but didn't want to renovate or buy a comparatively expensive weatherboard house with a backyard.
Through a real estate agent they met Legge, whose work they admired. Only afterwards did they realise they were being interviewed to see if they would fit into the community. While they benefited from buying off the plan, and appreciated the house's design, which didn't waste any space and has "great sound insulation", the biggest bonus was the community itself, Thomas says.
"A lot of my friends are jealous because they like the idea that you can just send your kids out to play, and having other kids to play with is a big bonus," she says. "The friendships are like having cousins. It has that vibe. People who you know so well, because you see them all the time."
While the kids come and go, everyone is quite respectful of each other's privacy, she says. "A lot of people might have been scared off by not having their own backyard, but for me it works better to have common space and share."
While not everyone has architects for friends, it is hoped the genesis of such a community (effectively, Legge recruiting a bunch of mates) can be replicated and magnified through social networking.
"In a way, Citiniche is reverse-engineering what we did at Heller Street," Legge says. (That is, instead of developing a project that attracts like-minded people, like-minded people help create something that suits them.)
"Most high-density [housing] is appalling around [Brunswick's] Sydney Road and [Carlton's] Lygon Street, and essentially completely developer-driven," he says. "It's trying to cram as much of it in as possible. What needs to happen is an exploration of all sorts of models for increasing the urban density.
"If you get everyone involved and they commit, all of a sudden you are in the same environment as the developer, looking for much larger pieces of land that are less expensive per square metre."
But will Citiniche make properties more affordable? Tim Jackson warns against unrealistic expectations. "Some communities could be quite naive in terms of their understanding of what they can get for a certain amount of money," he says.
Management costs of running big projects may preclude Citiniche developments from being vastly cheaper. After all, the niches will be competing for inner-city land against national developers dedicated to maximum yield and efficiencies of scale. But Jackson hopes that savings made by the developer on marketing and display suites could be passed on to buyers.
Says Rijavec: "My instinct is it will bring down prices, particularly if a project is totally subscribed. On the developer side, the risk is substantially reduced, and on the consumer side, they're getting something for less than on the open market [because of the buying power of a group]."
Yet while saving money is desirable, it's clear the emphasis is on having more control over the project and getting something closer to individual requirements while achieving the vaunted "good design".
Developer David Napier, executive director of Digital Harbour at Docklands, is keen to use Citiniche to produce something out of the ordinary for the 80 proposed apartments between La Trobe and Dudley streets.
Citiniche is encouraging website users to suggest ideas for a "green garden" apartment complex. Digital Harbour will monitor proposals and formulate concepts - perhaps.
"From our point of view, it's a test scenario," Napier says. "The market has a lot of 'same old same old' developments which are virtually just repetition ... what this is talking about is something that will actually cater specifically to the needs of the end owner-occupier of the unit. That appeals."
An architect with 25 years' experience as a developer, Napier is keen to explore an alternative approach to the development of Docklands apartment towers that might include low-rise developments with green roofs and parklands that allow light into the precinct.
But he is aware that consumers are also likely to have a "wait and see" approach. "You have to get the numbers. That's the biggest challenge [for Citiniche]. How deep is the market? How many are going to relate to this? It's untried here and how many people are willing to put down a deposit and to conform to ... a set of criteria which may not be 100 per cent what they want?
"If we felt it was 80 individuals wanting 80 different solutions, then I'd throw my hands in the air and say, 'That's not possible - go and buy a house'."
Local architectural precedents for creative multi-unit developments involve architects with vested interests, which brings an increased level of trust. But there are other lessons to be inferred for crowdhousing.
Architect Rob McBride, who has completed apartment developments with friends, which he and his family have always lived in, says that to ensure everyone is happy, it's important to have options presented clearly and upfront.
"Everyone understood it's not a completely bespoke service because it would be difficult to manage. But there was a good degree of being able to tailor your apartment. There may be potential savings to be made, but it seems more about suiting needs and making conscious decisions about what you think is important."
Rijavec says crowdsourcing is a "paradigm shift", akin to the introduction of "buying off the plan" in the 1980s.
"Going from bricks and mortar to a piece of paper is pretty scary - that would have been like jumping off a cliff and hoping your parachute would open for the first time," he says of those pioneering developments.
He says handing more power to buyers is a natural evolution. "Wouldn't it be common sense that if a group was underwriting a development that they could get a bigger say in what they wanted? When you look at what has happened with all the various online sites, there's no doubt that the time has come. It's really just a question of when, not if it's going to happen."