Montgomery County officials ordered a halt yesterday to work at a Silver Spring townhouse development where they say the builder has constructed houses that are too tall and too close to rear neighbors and has failed to create paths and play areas on time.

The stop work order at the 59-unit Seaton Square, a Ryan Homes development near Route 29 and Lockwood Drive in White Oak, is part of a review of new construction conducted by the county departments of Park and Planning and Permitting Services. Officials undertook the review after construction irregularities were unearthed by a community group at Clarksburg Town Center, a planned community in northern Montgomery.

Many of the Seaton Square homes, possibly as many as 48, are occupied, said development review chief Rose Krasnow. Eleven are under construction but nearly completed. The findings will not affect homeowners but will affect anyone ready to close on a house and move in, Krasnow said.

The Planning Board approved a site plan in October 2003 that sets a height limit of 35 feet and requires 20-foot rear yard setbacks, spokeswoman Nancy C. Lineman said. Preliminary measurements found that the townhouses, which are selling for more than $600,000, are 37 feet high, Lineman said. The structures also were found to be 16 feet, and possibly less, from the property line, Lineman said.

Krasnow said the zoning regulations for that area clearly permit houses no higher than 35 feet. "I don't know on what basis they didn't know what the height standard is," she said.

Dan Malzahn, a spokesman for Ryan Homes' parent company, NVR Inc., declined to comment.

This is the second stop work order on a large-scale development issued by the planning agency in recent weeks. On Oct. 26, the agency issued a stop work order at the Bethesda Crest townhouse development on Route 355, citing height and setback violations. No one has been allowed to close on houses or move in to the development, where some houses are selling for $2 million. A hearing on that order, originally scheduled for Thursday, has been postponed until Nov. 17.