When the people from E.F. Hutton & Co. talk, you're supposed to listen.

But at a new downtown Washington branch of Hutton, formally opened with a reception last night, the Hutton men and women plan to do a lot of listening before they start talking.

Simply stated, Hutton's officie at 1859 K St. NW is a new concept for the securities industry. The plush suite on the second floor of the new International Square complex doesn't ever look like a normal brokerage. There is no central room with rows of sales desks and an electronic wall display showing New York Stock Exchange prices.

As one visitor commented yesterday, Hutton's office looks like it belongs in the executive suite at a bank. Or in a law office.

But George L. Ball, the young and new president of the nation's second-largest securities company, said yesterday the Washington branch is considered a prototype for the Hutton of the future.

Total financial planning, one-on-one with customer and Hutton sales person in the privacy of a separate office, is the attraction the company hopes will bring customers to its doors.

Two former brokers here with Reynolds Securities, Perry H. Bacon and John C. Jennison, went to Hutton with a plan for the new concept last year and found an interested audience in the 38-year-old Ball and his associates. Ball who became president of Hutton about four months ago, previously was credited with giving his firm an aggressive sales image on Wall Street.

Bacon, who now manages the new branch, is taking his time in looking for a dozen "superstar" sales persons, people he calls "big producers" and who will add spark to everyone else in the office.

Jennison, who has drawn up a plan of total investment planning that will be employed with customers at the new office, said Hutton and many of its competitors always are ready and willing to handle the affairs of wealthy people.

What Hutton hopes to be successful with in its pilot branch on K Street, he added, is drawing up a program of investing for persons with more modest assets - in a range of $100,000 to $200,000, including homes.

In metropolitan Washington "there are many thousands of people" without such planning but with such assets, he said yesterday. In most cases, such people go to individual stock brokers, real estate brokers, insurance agents, accountants and lawyers, he added.

What the Hutton people hope to do is not replace these various professionals but provide an overall plan for specific goals - recommending types of insurance plans, investments in stocks, bonds or options, and factors to be considered in writing wills.

Jennison said that while insurance companies already offer investment planning, it is based on possible death. "We want to plan for living, as well," working on whatever goal a client may have, he said.

Customers at the Hutton office will first be subjected to an in-depth interview on their financial status - sessions that often take up to three hours or more to complete.At that time, Hutton people will listen and help to develop what Jennison called "realistic goals" from a plan of investment - whether it's to buy a yacht in 1985 or to educate children in college through the masters degree.

After this meeting, Hutton officials here will draw upon their firm's resources in New York and elsewhere to prepare a full analysis and draw up a "written plan for life" - one that will be followed thereafter, with modifications made in the event of sudden wealth or sudden loss.

Jennison has worked on the concept for several years and Bacon said his office will emphasize options writing, insurance, tax shelters and fixed income securities in its financial plans. Hutton offers on its own many of the financial services that will be suggested but Jennison said the staff will not recommend shifts away from current investments just to gain new commission businss.

In the words of Ball, "We want to be the orchestra leader, not play solo." With an increasingly complex world, it is impossible for one individual counselor to "stay abreast of the investment art," he added.

Although offices similar to the new Hutton branch have been offered in scattered spots over recent years, Ball said yesterday that none of these facilities "is in as complete a form" as the Washington pilot, "on which we hope to build."

Ball also said he expects the entire securities industry to step out with similar, innovative efforts - all aimed at making the marketplace more efficient in terms of individual investment.

In many respects, Hutton's competitors are watching Ball's firm for guidance on how to succeed. Among the nation's 50 largest diversified financial firms, Hutton is No. 2 in terms of profitability as related to equity.

In the securities business, Hutton is No. 1 in profitability and second only to Merrill Lynch, Pierce, Fenner & Smith in terms of size with 201 offices. When Hutton went public in 1972, it was the fourth largest securities firm with 82 offices.

Ball said Hutton plans to expand in the metropolitan Washington area from its current two offices. Other regional branches of Hutton are located in Baltimore and Norfolk.