He was employed by Ferdinand Meldahl on the construction of Fredericia Town Hall (1859) and later worked on the reconstruction of Frederiksborg Palace (1863–64), also under Meldahl. Lendorf managed his own firm in Odense (1864–83) and then in Copenhagen. He was drawing teacher at Odense Technical College (1846–83). Lendorf participated in the Nordic Exhibition of 1888. He was honored as a Knight of the Dannebrog, was awarded the Dannebrogordenens Hæderstegn, and served on the board of the Foreningen for Alderdoms-Friboliger.