The House Committee on Interior and Insular Affairs has asked the Pennsylvania Avenue Development Corporation (PADC) to delay demolition of the former Kann's Department Store building until after May 15, when its investigation into PADC's historic preservation practices is expected to be completed.

"We are concerned about whether PADC adequately evaluates alternatives when decisions are made to move or demolish buildings of historic or architectural singificance, such as Kann's Deparmtne Store," wrote Rep. Morris K. Udall, chairman of the committee that oversees PADC and controls its budget, in a letter formally notifying PADC Director W. Anderson Barnes of the investigation.

The letter was also signed by Reps. John Seiberling, Phillip Burton and Keith Sebelius, also members of the Interior Committee.

The committee, according to the letter, has asked the General Accounting Office to review PADC's historic preservation program, "focusing on Kann's Department Store as a case in point."

"We want to know whether applicable laws, regulations and proper procedures have been followed and whether the costs of demolition are being fully compared to the costs of other alternatives, including long-term adaptive re-use," wrote the committee members.

In December, PADC obtained a permit from the District government to demolish Kann's, which faces Pennsylvaina Avenue between 7th and 8th streets NW. The structure -- actually 14 Victorian commercial buildings until recently completely covered by aluminum siding -- stands in the way of PADC's planned "superblock," a proposed complex of 750 housing units plus shops and landscaped walkways.

Work on the "superblock" is not scheduled to begin until the early 1980s, but PADC proposed to clear the site and use it temporarily as a park and an area for craft fairs, according to PADC officials.

The demolition of Kann's has been in limbo for the past month, pending a decision by Secretary of the Interior Cecil Andrus on whether to remove the property from the National Register of Historic Places.

PADC officials say that if the property is not removed from the historic register, the buildings will not be torn down, since a developer who builds on the site of a landmark listed on the register is subject to tax penalties.

Andrus has not announced a decision on the matter. The Committee on Interior and Insular Affairs also oversees the Interior Department and its budget.

The letter reminded Barnes that May 15 is "also the deadline for legislative action with Fiscal Year 1980 budget impact."

A member of the committee staff explained that that date was significant only if the committee decided to initiate legislation that would affect the FY 1980 budget. Recommendations for cuts in PADC's funds would have to be made to the Appropriations Committee by March 15. PADC has requested an appropriation of $36,966,000 for FY 1980.

The staff member also explained that whether the committee will hold hearings as part of its investigation depends on the results of the GAO review, which is scheduled to be completed April 1.

PADC Director Barnes is out of town and could not be reached for comment. PADC 'spokesman Rita Abraham would not comment on the matter except to say that PADC would "cooperate fully with the committee."

PADC has budgeted more than $11 million for a historic preservation program that envisions preserving historic buildings, such as the Willard Hotel and the old Evening Star building, on their original sites. Other buildings, possibly including some of the small structures that made up Kann's Department Store, would be moved to a Historical Preservation Zone between Pennsylvania Avenue, 6th and 7th streets, and F Street, under the program.

"I want to emphasize that I have long been a supporter of the Pennsylvania Avenue Development plan," said Rep. Seiberling. "My not to halt development on Pennsylvania Avenue." But he added that "the historic preservation movement in this country has grown and greatly in 1975. Rehabilitation has shown to be often more cost effective and usually more energy saving than new construction. It does not appear that PADC has fully taken these things into account."