With high interest rates on mortgages making home-ownership a thing of the past or a pastime of the rich, growing numbers of middle class Americans are teaming up in innovative combinatins to enable them to buy homes.

Keen-eyed real estate agents are hastily putting together a new, match-making branch of the industry, introducing would-be buyers to would-be investors. Objects: a home for the buyer, a profit for the investor and a sale for the real estate agent.

Builders are constructing condominiums and town houses in new configurations intended to house unrelated buyers under the same roof.

Groups are forming, sometimes among friends and sometimes among strangers, to buy houses -- to live in or not -- that none of them alone could afford.

As is often the case, many of the new buying patterns began in California, reached the East Coast about a year ago and arrived in the Washington area within the last few months.

In economic motivation and as a general reflection of inflationary pressures, this developing trend has its counterpart in habits long in evidence among renters: Groups of people who may or may not know each other move in together to help meet monthly payments. In a larger sense, the group-buying movement is part of what the real estate industry calls creative financing -- new ways to make it possible to put together enough money to buy and sell homes.

"The only limit to creative financing is the creative limit of your mind," said Chris Albrick, a sales agent who is involved in one such deal.

How widespread is this new method? "My impression is that it's a new idea that's beginning to happen," said James Christian, chief economist of the Chicago-based U.S. League of Savings Association. No figures are available yet, he said, adding, "It's pretty fresh, as are most forms of creative financing. The reason it got started in California is the extreme price pressure there and the fact that it's still a pretty hot housing market."

Dick Fisher, a salesman in Northern Virginia with Long and Foster Realtors, claims credit for making the first matches between buyers and investors in the Washington area.

"We only broke ground on this in the last five months," Fischer said. "We found that many tenants caught in condominium conversions couldn't afford a down payment or monthly mortgage payments. I came up with the idea of finding investors who were willing to help."

Fischer said his first step was to seek guidance from an expert tax attorney and develop a legal framework to determine, among other things, what happens if the buyer-occupant or the investor wants to sell and the other partner doesn't. "I've seen enough owners-in-common at logger-heads to know that this can be a problem," he said.

Other details commonly spelled out in contracts would cover taxes and profits from the sale of a home.

Fischer did what he called "an exploratory" on Woodlake Towers, an apartment building near Seven Corners in Falls Church. Tenants there had received notice last October that the building was to be converted to a condominium. Fischer's first step was to pass out leaflets informing tenants that if they didn't want to move, he had some options for them.

Fischer succeeded in matching four tenants with four investors. The first of the deals went to settlement last week. George Baden, the investor in this completed contract, said he was delighted with the arrangement.

"I put up $4,000 for PITC (principle, interest, taxes and condominium fees) costs," Baden said, "and the tenant Dick teamed me with makes the mortgage payments. He also gets the tax write-off. When we sell the unit, we split 50-50. We anticipate that, conservatively, we'll each net $8,000 after taxes. That's a 100 percent profit for me. Where can you beat that?"

A major plus, particularly from the investor's viewpoint, is that the pair can buy the unit at the tenant's discount rate -- in Baden's case, $42,000 rather than the $55,000 street sale price.

"If I had four times the money," said Baden, 34, a federal government employee, "I'd go out and find four tenants to go in with."

Another match was being made in a rehabilitated Washington condominium at 18th and California Streets NW. Mark Morris, curly-haired and 25, sat there with arms crossed on his chest and chatted about his financial status and his housing demands: "Right now, I can afford about half of the kind of place I want to live in. I want a duplex, two bedrooms, a terrace, a view lots of luxuries, lots of space. That's what I'm going to get here. And the only way I can get it is with a partner to invest in it."

Across a glass-and-chrome coffee table sat that partner, Edgar Albrick, and his wife Edna, both nodding in silent approval.Albrick, 62, a retired Green Beret lieutenant colonel who fought in World War II, Korea and Vietnam and looks it -- close-cropped grayhair, steely eyes, broken nose, square jaw, lean, sinewy and supple -- explained his decision to invest in Morris' $118,900 unit and parking space:

"We've been traveling in and out of Washington for 40 years. While we've never lived here, it's clear that appreciatin on real estate here is terrific. If I can invest some money in a way where it can work for us and help a young fellow like Mark, well, so much the better."

Albrick was in Washington to visit his son, Chris, in whose condominium unit the conversation was taking place. The younger Albrick is the sales agent for the building. The Ashley, and The Ashley II rising next door. At Chris Albrick's suggestion, his father had already invested in his apartment and agreed to back Morris.

When a visitor asked to see Morris' unit, the party adjourned to The Ashley II and clambered up stairs littered with construction materials. At this stage, the apartment was just a raw concrete shell demarcated by galvanized steel studs and open junction boxes spilling electic wires like tangled spaghetti.

"I'm going to buy this?" said Edna Albrick in mock alarm, confirming that this was the first time she and her husband had seen the object of their investment. Edgar strode about, pausing to smack a stud with his palm and to pronounce it "solid."

It was not until several nights afterward that the Albricks and Morris sat down with Liza Bercovici, a young lawyer who recently broke into the buyer-investor matchmaking game, to sign the financial documents. In essence, their complex agreement calls for Albrick to pay two-thirds and Morris one-third and to reap their profits in the same proportions when they sell the unit.

New jersey realty agent Ellberger appears to be the first to franchise such a program, which he calls the Equity Sales Plan Inc., or ESP.

"We were having trouble with buyers, mostly young, first-time buyers, who had good jobs and good prospects, but hadn't been able to save enough cash for down payments," Ellberger said. "Another category was the recently divorced. So we couldn't sell them homes."

"At the same time, we had people coming in who had money and had heard of single-family homes being a good investment. But they didn't want the headaches that go along with being a landlord and they didn't want the negative cash flow inherent in rental property. So we couldn't sell them anything, either. It only made sense that these two categories should be brought together."

Ellberger, 38, who is president of the Sterling National Realty Group Inc., a franchise organization based in Ocean, N.J., said he spent a year and $160,000 on legal and tax research and drawing up copyrighted documents designed to protect the buyers and the investors.

He now has real estate agents using his plan in seven other states -- Tennessee, Florida, Georgia, New Mexico, Alabama, New York and Nebraska -- and the agents pay a fee to Sterling National.

"We've written 51 transactions since late April, ranging from $46,900 to $125,000, although the program is applicable to homes in almost any price range," Ellberger said.

In the basic ESP version of the plan, the would-be resident qualifies for the mortgage alone while the investor makes the down payment. They share tax benefits equally but the investor earns a 2-to-1 ratio on profits.

"In two or three years, this type of program will be generic," Ellberger predicted. "And it's not just for now. If interest rates come down, prices will rise and those young people at the bottom, who are trying to get their foot on the first rung of the ladder, will still have their problems."

Quite another approach to the same problem, again Californian in origin, is a house or condominium built specifically with two unrelated buyers in mind.

Dan O'Leary, a Washington builder, has gutted and rehabilitated two adjacent row houses in the 600 block of Morris Place NE. With two equal-size bedrooms and two full baths on the second floor, they're intended for two single people. And, priced at $127,000, "they're cheaper than condos," he said.

"Singles! Beat the System! Buy Together!" O'Leary's ads proclaim. But after being on the market 2 1/2 months, the houses are still unsold. "I don't think the concept has had a fair chance in Washington," he said. "It's because of the generally bad market and difficult financing."

A different solution for young people wanting to get into the market is to join with friends and buy a house together, forming their own condominium association. Susan Dillon, a Washington lawyer, bought a turn-of-the-century row house in the Dupont Circle area along with three friends for $185,000 in September 1979.

But converting the four-unit building to condominium status was another matter "We found that the D.C. Condominium Board wasn't used to four people owning the building they lived in and wanting to convert it themselves," Dillon said. "Their normal approach was to protect tenants from big developers. So we fell through the cracks."

Eventually, they hired a real estate attorney and recently cleared the last hurdle, registering the building as a condominium. Now they're planning to refinance, in order to have four separate mortgages. "Right now, it would be impossible for one of us to sell," Dillon said. "That makes it a good investment, but not exactly what you'd call liquid."