Fixed wireless access at mm/cm bands has been proposed for high-speed broadband access to suburban residential customers and building penetration loss is a key parameter. We report a measurement campaign at 28 GHz in a New Jersey suburban residential neighborhood for three representative single-family homes. A base antenna is mounted at 3-meter height, emulating a base station on a lamppost, moves down the street up to 200 meters. A customer premises equipment (CPE) device, acting as relay to provide indoor coverage throughout the desired area, is mounted either on the exterior of a street-facing window or 1.5 meters behind the window. The median indoor-outdoor path gain difference, corresponding to the extra loss by moving the window-mounted CPE indoor, is found to be 9 dB for the house with low-loss materials and plain-glass windows, and 17 dB for the house with low-emissivity windows and foil-backed insulation. These losses are in addition to other losses (e.g., vegetation blockage) in comparison to free space propagation.