A standard San Diego home inspection is not an energy audit, but it surfaces most of what drives your SDG&E bill: thin or missing insulation, single-pane windows, an aging or oversized HVAC system, and a poorly ventilated attic. We document these as visual observations – not a HERS score – so you walk in knowing where the comfort and cost problems likely sit.
Energy efficiency in a home inspection vs. a HERS rating
It helps to be clear about scope up front. A general inspection is a visual, non-invasive evaluation of the home’s condition. When we comment on energy efficiency, we are reporting what we can see and reasonably infer – not running blower-door tests, duct-leakage measurements, or modeling software.
A HERS rating (Home Energy Rating System) is a different, regulated service. A certified HERS rater uses calibrated equipment to produce a numbered score California ties to Title 24 energy code compliance, often required when you replace ductwork, add an AC system, or finish certain remodels. If you need that document for a permit or to qualify for a rebate, you need a HERS rater, not a home inspector.
What an inspection gives you instead is practical and free of the rating overhead: a plain-English read on the building’s biggest energy weak points, captured during the same visit you are already paying for as part of a buyer’s home inspection. For most San Diego buyers, that is exactly the information they need to budget and negotiate.
Insulation: the single biggest lever in older SD homes
San Diego’s climate is forgiving, which is precisely why so many older homes here were built with minimal insulation – and never upgraded. We routinely find attics in pre-1980 Clairemont, La Mesa, and El Cajon homes with one to three inches of settled, displaced, or simply absent insulation, well below today’s typical R-30 to R-38 attic targets.
During the inspection we look at:
- Attic floor insulation – depth, type (loose-fill, batts, none), and whether it has been compressed, pushed aside by past trades, or contaminated by rodent activity.
- Coverage gaps – missing insulation over additions, garages converted to living space, and around can lights or attic hatches.
- Wall insulation clues – we cannot see inside finished walls, but exterior wall temperature, comfort complaints, and the home’s era give us a reasonable read.
Insulation is usually the highest-return energy fix in a San Diego home because it is comparatively cheap and it cuts both cooling load in the inland heat and heating load on those 45-degree coastal winter mornings. For a deeper look at what we find overhead, see our guide to attic insulation and ventilation in San Diego homes.
Windows: single-pane vs. dual-pane
Windows are one of the easiest efficiency factors to assess visually, and they matter more on the coast than people expect. A lot of original 1950s-70s housing stock in Point Loma, North Park, and Chula Vista still has single-pane aluminum windows – thin glass in a metal frame that conducts heat readily and sweats with condensation.
We note window type and condition because it tells you a lot at a glance:
- Single-pane glass – one layer, often in non-thermally-broken aluminum frames; the least efficient and a frequent source of drafts and condensation.
- Dual-pane (double-glazed) – two layers with a sealed air or gas gap; far better at controlling heat transfer and noise, which matters near I-5, I-805, and flight paths around Montgomery and the airport.
- Failed seals – foggy or hazy glass between the panes means the seal has failed and the unit’s insulating value has dropped. We flag these even though the window still “works.”
Full window replacement is expensive, so this is rarely a deal-breaker – but it is real budget information, and on a coastal home the noise and salt-air corrosion angle often pushes the decision more than the energy savings alone.
HVAC efficiency and the right-sizing question
We operate the heating and cooling system in normal mode and report what we observe: whether it runs, approximate age from the data plate, condition, and obvious red flags like a rusted heat exchanger area, dirty coils, or a unit that short-cycles. Age is a strong proxy for efficiency – a 20-year-old condenser is both near end of life and far less efficient than current equipment.
A San Diego-specific note: oversized AC is common and counterproductive. Contractors sometimes install a bigger unit than the house needs, assuming bigger is better. An oversized system cools fast, shuts off, and never runs long enough to pull humidity or distribute air evenly – so you get hot-and-cold rooms and higher bills. We cannot calculate the load (that is a Manual J / HERS-level analysis), but we can flag the symptoms and recommend an HVAC contractor evaluate it.
We also look at the ductwork we can access – disconnected runs, crushed flex duct, and missing insulation on ducts in a hot attic all waste conditioned air before it reaches the room. Leaky attic ducts are one of the quietest, most expensive efficiency drains in inland homes.
Attic ventilation: comfort, bills, and roof life
Ventilation and insulation work together. A properly vented attic exhausts the heat that builds up under a dark roof on a 95-degree Escondido afternoon, which keeps the ceiling – and your AC – from fighting a superheated space all day. Poor ventilation also traps moisture, which shortens roof and sheathing life.
We check for balanced intake (soffit/eave) and exhaust (ridge, gable, or static vents), and look for the common failures: vents painted or insulated shut, no intake at all, or a bathroom fan dumping moist air directly into the attic. These are usually low-cost corrections with an outsized effect on both energy use and durability. If you want the system looked at from above as well, our roof inspection service pairs naturally with the attic evaluation.
Thermal imaging: finding the gaps you cannot see
An infrared camera does not see through walls, but it reads surface temperature differences – and that makes hidden energy problems visible. On the right day (when there is a meaningful temperature difference between inside and outside), thermal imaging can reveal:
- Missing or thin insulation showing as warm or cool patches across a ceiling or wall.
- Air leakage around windows, doors, recessed lights, and attic hatches.
- Duct and register losses, and sometimes moisture intrusion that is also driving comfort issues.
It is a screening tool, not proof – anomalies get confirmed with a moisture meter or further investigation. Learn more about how we use it on our thermal imaging page.
How to use this information as a buyer
None of this typically kills a deal, but together it sketches your real cost of ownership: an under-insulated 1965 home with single-pane windows and a 2003 furnace will cost more to run and improve than a 2015 build, and that belongs in your budget and your negotiation.
Pricing for our inspections depends on the home’s square footage, age, and access – see our fee schedule for how that works. Have questions about energy efficiency on a specific San Diego property? Call The Real Estate Inspection Company at (619) 752-4399 or contact us to schedule. For a HERS rating tied to permits or Title 24, we will point you to a certified rater, and for any code or rebate questions, confirm details with your contractor and SDG&E.
