Plans have been lodged with Dacorum Borough Council in connection with work to turn part of a row of historic cottages in Piccotts End into an office and homes.
Details of external materials, a parking area and landscaping are included in the papers, which relate to 15th century cottages that it is believed were used as a hostel for pilgrims.
Almost 10 years ago permission was granted to create two homes and a combined office and museum – containing historically important religious wall paintings – in the three cottages.
This followed failed efforts by the council to purchase the cottages to create a museum in partnership with Dacorum Heritage Trust.
The value of the cottages was discovered in 1953 when the medieval wall paintings were discovered during repair work.
The paintings were found in an upper room hidden behind several layers of wall paper.
The cottages also feature an Elizabethan painted bedroom and a priest’s hide.
Near to the cottages a set of buildings, now demolished, were used in 1826 as one of the country’s first hospitals by eminent surgeon Sir Astley Cooper.