Back in 1929, George C. Pearson, an elder of the United Church of Christ parish in Cavetown, Md., willed his church $100,000 for the care of the elderly.

"That $100,000 today is worth $15 million," said the Rev. Roderick J. Wagner, president of Homewood Retirement Centers, which built four retirement communities affiliated with the United Church of Christ and made possible by the gift.

Homewood, at Williamsport, Md., is the only full-service retirement center of the four. It is situated on a 20-acre tract about three miles south of Hagerstown. The others are in Hanover and Martinsburg, Pa., and Frederick, Md.

Wagner has developed and executed plans during the past nine years to surround the home with one- and two-bedroom cottages and an apartment house. Groundbreaking ceremonies were held last month for a community center, which will include a swimming pool, spa, ceramic room, shuffleboard courts, sauna, beauty and barber shops, kitchen, meeting rooms, library, post office and bank.

"There is a lack of appropriate housing for retirment-age people," Wagner said. "The existing houses are too large and too expensive to maintain."

Wagnersaid that he believes retirement-age people are going to buy into retirement homes. He predicts an excellent market for economical retirement houses for the next 20 years, particularly if the sponsors of the project are willing to add some support services and amenities, such as the community center now under way at the Williamsport facility.

"I don't see that there is a future" for standard nursing homes, Wagner said. "One, there are alternate ways of recovery care such as Meals on Wheels, visiting nurses, etc. And, two, it's too expensive," he elaborated.

"I would live in one of my own nursing homes. We try to promote the style of living that we ourselves would enjoy," Wagner said. He noted that the motto at Homewood is "Those in our care are an older us."

The cottage project started in 1981 with 28 units, all of which sold immediately. Twenty-six more units have been finished this year; all but one sold before completion.

Construction has begun on a cluster of 11 cottages, with occupancy projected for next spring. Nine of these are spoken for already. By 1984, the site will hold 97 cottages and 59 apartments.

"In the next 20 years, this site will be saturated. It will be a nice community," Wagner predicted.

The promoters of Homewood Retirement Centers went against the advice of the professionals when they built cottages adjacent to the nursing home. "We were told by the pros it would have an adverse effect on potential buyers," Wagner recalled.

He has found the opposite to be true. "The people who come here looking for retirement homes like to think, if anyting happens to them, they can be cared for right here," Wagner explained. "We try to maintain the separation between the residential community and the health care facility to avoid premature institutionalization," he added.

The all-electric cottages are situated on attractive, landscaped grounds. Each has a walled English garden in front and a patio, storage shed and small yard area for gardening in back.

"Doc" Cline, job superintendent for Morgan-Keller, Inc., the construction firm developing the project, said each of the 950- to 1,250-square-foot units is built on a concrete slab and has cedar siding, asphalt roof shingles and insulated vinyl windows.

The all-electric kitchens feature self-cleaning ovens, disposers, frost-free refigerators and optional dishwashers. Draperies and carpeting are included with the purchase. Stack wash/dryers and laundry shelves are placed in a small laundry area.

No space is wasted in the units, which include a living/dining area. A "window" from kitchen to dining space indicates the sensitivity of the designers to reducing footsteps for the elderly owners. A constantly monitored electronic signal provides instant communication between each cottage and a nursing station.

Homewood buyers must be at least 60. Thus far, the average age is 72.

Buyers pay the amount their cottage cost to construct. Cottage prices range from $45,900 for a one-bedroom unit with den to $59,900 for a two-bedroom unit with a den. The apartment units cost between $24,900 for a studio to $44,400 for a two-bedroom unit.

There is a $50-a-month condominium charge, which includes fees for garbage collection, water, sewer and security. Utilities are extra.

Thirty-one years ago, Wagner's father, the Rev. Mark G. Wagner, ended 17 years of ministering to his parish to become the first administrator of the Williamsport facility, which then included only a 136-room nursing home.

His son is a Franklin and Marshall graduate, who received his divinity degree from the University of Chicago Divinity School and then spent four years in a parish before returning to succeed his father as administrator when he retired in 1973.

When asked why he doesn't refer to himself as a clergyman or include the title on his business cards, Wagner remarked, "I am a business-oriented. There are people who say anyone who has been a minister can't read a balance sheet!"