On an evening earlier this month, 100 friends of Charles Patrick McMahon gathered at the University Club to tell the retiring senior vice president of the National Association of Home Builders that they think he's a nice guy. Robert F. Loftus, who once headed the public relations department at NAHB, credited McMahon with coming up with the bestever slogan for National Home Week: "If you don't believe that home builders care about little people, just look at the houses we build for them."

Private mortgage insurance was used to help finance 188,190 single-family houses in a recent three-month period while the FHA and VA provided mortgage insurance or guarantees for home loans for a total of 172,792 dwellings. That, according to the area-based Mortgage Insurance Companies of America, is the first time that the private sector outdid the federal sector in that field. Meanwhile, the Department of Housing and Urban Development has been working to revive its FHA program of mortgage insurance that once dominated the market for low- and moderately-priced houses.

If you have to be convinced that people never really leave Washington, consider that Oliver H. Jones and wife have moved into a smashing contemporary house in the mountains of southern Pennsylvania since he exited from the top staff post with the Mortgage Bankers Association here. But the Jones' have rented an apartment on Connecticut Avenue NW, opposite the Washington Hilton, to be their residence when they are in town.

Higher-priced, single-family houses tend to have some special features. At the newly opened Langley Oaks subdivision of the Centex Corp. on a wooded 300-acre tract next to the Langley High School, the four models have large master bedrooms. But they also have something unusual in tract house master bedrooms - tubs as well as shower stalls. This feature has caught the eyes of buyers, who are willing to wait months for completion of the $130,000 houses.

House & Home magazine, a trade publication beamed to home builders and developers, gives the Veterans Administration high marks in an article in the October edition. Quote: "The government's best-run, least troublesome, most scandal-free housing program is financing new housing at a level about one-third higher this fiscal year than last." In March, April, May and June, the VA mortgage guaranty program was used for 12,000 new houses earch month.