IDDEL has office at Anderson House. This is the oldest building in Newfoundland, built circa 1804-1805, It was originally built for and occupied by Lieutenant James Anderson, Commanding Officer of Signal Hill Battery. Anderson House was designated a Registered Heritage Structure by the Heritage Foundation of Newfoundland and Labrador in 1996. See more about Anderson House at Heritage Foundation of Newfoundland and Labrador.

Anderson House is a two and one half story hip roofed heritage-designated building located at 42 Powers Court, St. John's, Newfoundland and Labrador. It is a Georgian style building and is reported to be one of the oldest structures in the city.

The house is an excellent example of 19th-century housing. It was built on land that was purchased from Dr. J. Ogden, a Newfoundland chief justice, in 1802. It was constructed sometime around 1803-1804, possibly for Sgt, J, Anderson. Anderson held land in that area at least by 1808, as in September of 1819, the Newfoundland Mercantile Journal gave notice of the public auction of a property lot in the vicinity of the upper part of Maggoty Cove, Signal Hill. An 1849 map shows the house sitting on what is called "Anderson's Ground." Oral history maintains the house was used both as a private residence and as a military barracks with a section of the house used to stable horses.  In 1818, Anderson opened the “St. Johns’ Spruce Beer Brewery” at the upper wharf of J. Dunscome on the St. John's waterfront.  H. C. Tillmann, a professor of music and a composer who arrived in St. John's in 1844 from Halifax, Nova Scotia, purchased the home from Anderson's wife, after his death, in 1860.

Mary Tillman, wife of Henry, sold the property to John Power some time between 1862 and 1864. In 1878 he in turn sold it to Patrick Power. At some point the property passed from a Mary Power to her husband, William Finlay, who owned the property in 1970. 

After 1972, the building began to decay rapidly. In 1973, it was noted that in spite of a fire a number of years previously, the interior of the building was fairly intact, including a simple spiral staircase and two open fireplaces. In 1976, following a four-year campaign to save the building, the Newfoundland Historic Trust purchased the building and entered into an agreement with The Architect's Guild to restore the building. On 7 October of that year, shortly after the Trust signed the papers to take over the empty building, another fire caused serious damage to the structure.

Between 1977-78, much of the building was restored, and an eastern addition (which possibly served as the stable) was removed. 
 
The east end of the building, which was of a later date, was torn down as it was felt to be too damaged by fire to be rebuilt, and the house re-emerged in its original shape.