Finding out who built your house is a relatively simple task if the structure was built after the creation of your community's code enforcement and/or planning departments, which require builders to submit their plans to the local municipal offices and get approval from a governing body. But if you live in a very old home, be prepared for a trip to the property abstract room at the county office building. Either way, you're using public records to find the answer.
View your mortgage and title records to verify the year the house was built. If the construction was in recent years, the builder's appearance before the local planning board may be listed on the town/city's website. The name of the subdivision would be noted in those documents.
Visit town/city hall. Ask to see planning board minutes from a range of dates prior to the home's construction. Often, builders are given a time period for which they are required to complete the project after receiving site plan approval. You can also ask to see all of the housing development plans that were submitted in recent years before your home was built.
Stop at the county clerk/recorder's office. Search the deed books starting with the information you already have on your property. When a deed is recorded, a permanent record is often made and a number noting a deed book volume and page number is assigned to that document. The books are organised by date, and each document will give you identifier information to trace it back to the record of a previous owner noted in a different book. When you trace the deed all the way back to the property's first entry, that record will note the first owner and possibly who built the home.