Single rooms--those rarities enjoyed mostly by seniors and Quad-dwellers--will become a bit rarer next year when Lowell House becomes the fifth River House to adopt a no-singles rooming policy.

The four other River Houses that have single suites, Adams, Kirkland, Leverett and Quincy Houses, currently have no plans to phase them out.

Sheila Schimmel, secretary of Lowell House, said yesterday that as many as possible of Lowell's 47 singles will be eliminated next year to ease the House's overcrowding.

"If they're attachable to another suite, or if we can turn them into tutors' suites, we'll do it," she said. She estimated that 11 single suites might have to be left unchanged because of their size and construction.

Schimmel said the decision to cut back on singles was partly influenced by recent studies demonstrating the overcrowding problem in undergraduate houses. She added that most Lowell residents were willing to forego senior singles to lessen overcrowding during their sophomore and junior years.

Single rooms are available to most upperclassmen in the three Radcliffe Houses, and officials in North, South and Currier Houses said yesterday there will be no change in policy.

Dunster, Eliot, Mather and Winthrop Houses either have no single suites or permit them only in exceptional cases.