The L'Enfant Trust, a Washington architectural preservation organization, said this week that it has obtained "conservation easements" on two Capitol Hill houses.

Conservation (Illegible Word) -- agreements in which the owners agree not to change the faced of the building without permission of the trust -- are designed to preserve the character of buildings and neighborhoods while leaving property(Illegible Word) private hands. Owners of buildings in historic areas such as Capitol Hill, Georgetown and Dupont Circle can donate the easements -- in effect, the right to alter their properties -- to qualified recipients such as the L'Enfant Trust, and then deduct the value of the donation from their taxes.

The two recently received by the L'Enfant Trust are for 920 D St. NE, given by Clem and Edward Rastatter, and for 613 Constitution Ave. NE, given by Samuel and Marilyn Schoenbaum.

The house at 920 D St., above, was built in 1903. It is a corner house in a group of five rowhouses built by Joseph D. Aiken. The property is distinguished by a massive arched Romanesque Revival entry, quite different from the other four houses, which run along 10th Street.

The Constitution Avenue house was designed by Washington architect Glenn Brown, who was noted for his public buildings as well as private homes. He designed the Dumbarton Bridge, which crosses Rock Creek Park at Q Street NW.