It shouldn’t do. Most companies will do all the interior work first, and the last job to do will be creating the opening from the house to the conversion. A reputable company will make sure they cause as little disruption as possible during this time.
Perranporth
Perranporth is a seaside hotel town on the north shore of Cornwall, England, UK. It is 1 mile eastern of the St Agnes Heritage Coastline, and also around 8 miles south-west of Newquay. Perranporth and its 3 miles (5 km) long beach encounter the Atlantic Ocean. It has a population of 3,066, as well as is the largest settlement in the civil parish of Perranzabuloe. It has a selecting ward in its own name, whose population was 4,270 in the 2011 census. The community's modern name comes from Porth Peran, the Cornish for the cove of Saint Piran, the patron saint of Cornwall. He started St Piran's Oratory on Penhale Sands near Perranporth in the 7th century. Hidden under sand for several centuries, it was unearthed in the 19th century.