This paper describes the technical challenges of a project to expose a major share of the European building and construction materials market on the basis of the GoodRelations Web vocabulary for e-commerce. This allows for the fine-grained search for products, suppliers, and warehouses for any building-related sourcing needs. Because building materials show a very high item specificity, they are very interesting for new types of search. The result of this project is one of the largest and richest public datasets for a well-defined trade sector that is available on the Semantic Web.