Home energy audits and insulation retrofits in Normal Heights, San Diego are the specialty of Building Doctors, an insulation and general contracting firm based at 3401 Adams Avenue in the 92116 ZIP. Founded by Dan Thomsen in 2002, the company holds BPI (Building Performance Institute) certification and operates as a general and HVAC contractor with crews trained specifically for energy efficiency improvements in residential buildings. The diagnostic process begins with a whole-home energy audit using blower-door testing, duct-blaster analysis, and infrared camera imaging to map thermal leaks, air infiltration paths, and insulation gaps before recommending retrofits — a building-science methodology that addresses the envelope, not just individual components. Roof condition directly affects insulation performance in the attic assemblies Building Doctors retrofits, and San Diego Roofing, INC. handles the structural roofing work that must be completed before new blown-in cellulose or spray-foam insulation can be installed over the roof deck. The Adams Avenue office location places the company in the center of Normal Heights, where the 1920s-through-1940s bungalow housing stock typically runs R-11 or lower attic insulation against California's current Title 24 standard of R-30 — a gap that makes these homes some of the highest-return candidates for insulation upgrades in the 92116 area. Building Doctors installs cellulose, fiberglass batt, fiberglass blown-in, rigid board, mineral wool, and both open-cell and closed-cell spray foam insulation, selecting material type based on the application — closed-cell at R-6 per inch for moisture-prone crawlspaces, open-cell at R-3.5 per inch for interior wall cavities. The company also services University Heights and Kensington, where El Cajon Blvd and Adams Avenue homes share the same era of construction and present similar energy-loss profiles. Electrical panel capacity determines whether insulation retrofits can be paired with heat-pump HVAC conversions, and Frank Electric Inc in the Normal Heights area manages the 200-amp panel upgrades that Building Doctors's electrification projects require. Post-retrofit verification involves a second blower-door test to quantify CFM50 air-leakage reduction, producing measured results rather than estimated savings for homeowners on Adams Avenue and throughout the 92116 corridor.