They dominate three major inner-south projects awaiting planning approval.

In a $33.8 million, six-storey development on Eastlake Parade, Kingston, 94 of the 146 proposed units are for single-bedroom dwellings.

In a $69 million project in Irving Street, Phillip, 171 of the 278 units will be single-bedroom accommodation.

In Griffith a redevelopment for 76 residential apartments will comprise 57 one-bedroom apartments.

Banks once shunned them, but as Housing Industry Association chief economist Harley Dale points out, even with a credit crunch's negative impact on residential development, lenders must be coming to the party. ''It's difficult to see how you would get a critical mass of projects actually flying to fruition with a lot of one bedders in them if there had not been some kind of change in attitude.''

The Australian Bureau of Statistics says lone-person households are projected to show the greatest percentage increase up to 2031.

The number will rise by between 63 per cent and 91 per cent, or 1.2 to 1.7 million households, mainly because of older women, in particular, being more likely to live alone.

Cox Humphries Moss architect Chris Millman says the single-bedroom option is market driven.

''There was a point in time where we were doing large two bedrooms and this has moved to one bedroom. We've even had a lot of studio stock come into play.

''You can get mortgage insurance for about 40sqm whereas it used to be a lot bigger than that. As a result you get people investing, or an owner occupier that can go into smaller units because they can afford them and get mortgage insurance.

''Five years ago you would not have sold any studio units, now it is popping into the mix.

''The latest trend is you are seeing two-bedroom units with a single bathroom, again because they are a bit more affordable.''

Proponents of the $15.4 million Griffith redevelopment between Canberra Avenue and Leichhardt Street say proximity to Parliament House, Manuka, Kingston and Fyshwick means parks, sports ovals, colleges and schools are nearby, making it a prime area for residential development.

Its designers, Colin Stewart Architects, say the design responds to Griffith and Kingston's commercial warehouse history and features an internal covered courtyard or gallery for a central circulation space for residents.

The gallery and a swimming pool also serve as the main communal area and would allow increased solar access and cross ventilation to apartments.

The design has been changed to address government planners' concerns about its commercial zone location, rather than a town centre, and solar access.