“Tract” or “production” home builders generally have a small set of stock plans, of which they will not allow changes to be made. Lot selection will be limited or non-existent with home designs very square or boxy. Roof pitches are not as steep, windows and variable ceiling heights kept to a minimum. Most everything is an upgrade; for example, fireplaces, separate showers, jetted tubs, radiant barrier roofing and island kitchens just to name a few. Upgrading to these basics can be expensive!