The answer to the question: What building the architect and owner of Portland's quarries design and build? is inside the article: Weymouth originated as a settlement on a constricted site to the south and west of Weymouth Harbour, an outlying part of Wyke Regis. The town developed from the mid 12th century onwards, but was not noted until the 13th century. By 1252 it was established as a seaport and became a chartered borough. Melcombe Regis developed separately on the peninsula to the north of the harbour; it was mentioned as a licensed wool port in 1310. French raiders found the port so accessible that in 1433 the staple was transferred to Poole. Melcombe Regis is thought to be the first port at which the Black Death came into England in June 1348, possibly either aboard a spice ship or an army ship. In their early history Weymouth and Melcombe Regis were rivals for trade and industry, but the towns were united in an Act of Parliament in 1571 to form a double borough. Both towns have become known as Weymouth, despite Melcombe Regis being the main centre. The villages of Upwey, Broadwey, Preston, Wyke Regis, Chickerell, Southill, Radipole and Littlemoor have become part of the built-up area. King Henry VIII had two Device Forts built to protect the south Dorset coast from invasion in the 1530s: Sandsfoot Castle in Wyke Regis and Portland Castle in Castletown. Parts of Sandsfoot have fallen into the sea due to coastal erosion. During the English Civil War, around 250 people were killed in the local Crabchurch Conspiracy in February 1645.  In 1635, on board the ship Charity, around 100 emigrants from the town crossed the Atlantic Ocean and settled in Weymouth, Massachusetts. More townspeople emigrated to the Americas to bolster the population of Weymouth, Nova Scotia and Salem, Massachusetts; then called Naumking. There are memorials to this on the side of Weymouth Harbour and near to Weymouth Pavilion and Weymouth Sea Life Tower. The architect Sir Christopher Wren was the Member of Parliament for Weymouth in 1702, and controlled nearby Portland's quarries from 1675 to 1717. When he designed St Paul's Cathedral, Wren had it built out of..., can you guess it ?
St Paul's Cathedral