Here we go again.

Baby boomers, having practically remade the western world in their own image, are gearing down for retirement, and this time it's the housing market that's being transfigured.

Or at least getting a nip and tuck.

Some 3.7 million Canadian boomers are between 55 and 64 years old, prime retirement age, according to Statistics Canada's 2006 census.

In less than 10 years, that age group will skyrocket to one in five Canadians.

True, it will take a while for all the boomers -- those born between 1946 and 1965 and the largest group in the Canadian population--to take the golden handshake.

And no one knows exactly what housing choices they will finally make or how it will impact the market.

But count on this: the huge numbers will mean changes to how and where we live.

The changes have already started, with builders unveiling adult-lifestyle communities of bungalow townhomes, sometimes including a central community centre where residents gather for cards, potlucks or swimming classes.

Condo builders are attracting silver buyers with luxury apartments featuring tennis courts and hobby rooms.

The momentum for housing alternatives is building.

For starters, 28 per cent of Canadians polled in a 2006 Royal LePage survey said they intend to sell their homes as part of their retirement plan.

Granted, the downturn in the housing market has temporarily shrunk resale opportunities, and many Canadians, stung by the recession, have postponed retirement.

But stability will return and hordes of boomers will be scouting for new digs.

Depending on immigration patterns, the homes left behind could be snapped up by new Canadians or by younger folks; if boomers move downtown, their old homes could help ease urban sprawl.

For sure, the face of older, established neighbourhoods will change.

That same Royal LePage survey found that about 37 per cent of relocating boomers will want a smaller home.

"Developers are already thinking in those terms," says Pierre de Varennes, president-elect of the Ottawa Real Estate Board.

He points to the growth in condos and bungalows as examples. "Fifteen years ago, we saw very few bungalows being built."

Along with lower operating costs and less maintenance, one-storey homes are easier on aging joints, says de Varennes.

The demand for smaller homes is fuelling price increases, at least in condominiums.

According to Sandra Perez Torres, CMHC's senior market analyst for Ottawa, retirees and young professionals are the major buyers of condos.

Relatively higher condo prices --and retirees helping ignite them--were the story in most major Canadian cities, says Perez Torres.

Whether it's a condo, bungalow or a spot in one of the adult communities springing up across Canada and gaining popularity in the United States, boomers are demanding amenities to complement their active lives.

Soaker tubs and space for hobbies are de rigueur. Ditto proximity to bike paths and fitness centres -- and while a well-appointed kitchen is a plus, big is not always better; retired boomers like restaurants.

Not that boomers are about to move far for these amenities. Between 1990 and 2000, according to AARP (formerly the American Association of Retired Persons), nine out of 10 Americans over 60 were living in the same county in which they'd lived five years earlier.

More significantly, more than 75 per cent of those in the survey stayed in the same house--not all that different from the Royal LePage finding in 2006, but the absolute numbers are mushrooming.