The AC Never Shut Off.
The Attic Was Why.
A BPI-certified $100 energy audit on a 1958 Timonium rancher — what was causing a 12-degree temperature swing, the four findings driving it, and how the homeowner qualified for $6,310.98 in BGE rebates and $493.52 in annual savings.
At a Glance
Blower door · Infrared camera · Combustion safety · Written report with BGE savings projections — all included in the $100 audit. Schedule your audit →
High Bills. A First Floor That Never Cooled Down.
The homeowner's complaint was specific: the basement stayed noticeably cold while the first floor remained warm and stuffy — even with the AC running constantly. Energy bills were higher than made sense for a home this size.
The root cause wasn't the AC unit. It was what happened to conditioned air after it left the system. The air handler in the basement was doing its job — cooling air and pushing it upstairs — but the poorly insulated, leaky attic was absorbing it almost immediately. The system ran continuously trying to compensate for what it was losing overhead.
Measured whole-house air leakage from blower door test — the rate at which the entire volume of air in the home escapes each hour under test pressure. Significantly above the threshold associated with chronic comfort problems.
The audit found four distinct problems — two major air leaks driving the temperature swing, a decades-old insulation failure, and a ventilation deficiency that will become significantly worse once the envelope is tightened. Each finding has a clear, documented fix.
What the Blower Door & Infrared Camera Revealed
The audit depressurizes the house to a standard test pressure, then uses an infrared camera to show exactly where conditioned air is escaping. These leaks are invisible to a normal inspection — they only appear under pressure. Here's what we found in this home.
A Whole-House Fan Acting as a Permanent Open Window
The whole-house fan in the hallway ceiling was the dominant air leak found during the audit. These fans were standard equipment in 1950s–60s homes — designed to pull cool night air through the house and exhaust it through the attic. In the right season, they work well.
The problem is what they do the other ten months of the year. The louvers on most whole-house fans seal poorly, and the gap between the fan housing and the attic is essentially an unobstructed opening — conditioned air flows through it freely in both directions. In summer, this home's AC was competing with a hole it could never close.
A Cold Rectangle in the Ceiling
The second major finding was the pull-down attic staircase. Under blower door pressure, the infrared camera showed the entire stair assembly as a distinct thermal anomaly — conditioned air was flowing around the frame, through the folding mechanism gaps, and directly into the attic above.
Pull-down stairs are a near-universal problem in homes from this era. The stair has no insulation, the frame sits in direct contact with the attic, and the perimeter gap is almost never sealed at original construction. In a small rancher where every square foot counts thermally, this opening carries outsized weight.
Sixty-Six Years of Settlement
The attic insulation was original to the 1958 construction. What was installed then had settled, compressed, and degraded over six decades to approximately R-7. Maryland Energy Code requires R-49 in attics. This home had roughly one-seventh of the required level.
For a rancher, inadequate attic insulation isn't a background problem — it's the primary driver of comfort failure. The entire living space sits directly beneath the attic with no buffer. A poorly insulated Maryland attic regularly reaches 130–140°F on peak summer days. The ceiling between that environment and the living area at R-7 was doing almost no work.
Visible Mold at the Bathroom Ceiling — No Fan, Nowhere for Moisture to Go
The first floor bathroom had no exhaust fan and visible mold growth at the ceiling. Shower and bath moisture had nowhere to go except into the ceiling assembly. This is a health issue on its own — but the more urgent point is what happens after the recommended attic work is completed.
The roofline encapsulation and air sealing work will make this home meaningfully tighter. A tighter home holds moisture in the air longer. Without a mechanical exhaust path, the shower moisture that's currently causing mold will become more concentrated, not less. The attic work creates an obligation to address the ventilation at the same time.
Converting the Attic from Liability to Conditioned Storage
Insulating the attic floor wasn't the right answer for this home. The homeowner needed usable storage space — this is a 1958 rancher, smaller than what gets built today, and the attic is one of the only places to keep things. Spray foam roofline encapsulation solves both problems at once: it converts the attic to conditioned space while addressing the whole-house fan and pull-down stair leaks as part of the same application.
By insulating the roofline and gable walls, the attic goes from the primary source of the home's comfort and efficiency problems to a fully usable, conditioned part of the house. The AC runs less because it's no longer competing with 130–140°F overhead.
Two BGE Programs. One Audit Unlocked Both.
Timonium is BGE service territory. This homeowner had access to two separate programs — and the audit identified both during the same visit.
BGE Home Performance w/ ENERGY STAR
Rebates for insulation, air sealing, and related improvements — up to $15,000 for eligible work. As a BGE-approved contractor, we handle all rebate paperwork. Applied directly to your project cost.
BGE Free HVAC Tune-Up
The audit flagged a 12-year-old AC unit. Before any replacement decision, we referred the homeowner to BGE's no-cost inspection program. Fixing the envelope often defers replacement by years — or makes it unnecessary.
Why Envelope First?
An AC running hard in a leaky home isn't failing — it's compensating for building envelope problems. Sealing and insulating the attic reduces the system's load significantly. Most aging systems perform fine once the envelope is fixed.
We Handle the Paperwork
BGE rebate programs are confusing to navigate. As an approved contractor, we manage the entire submission. You don't coordinate with BGE directly — savings are applied to your project cost upfront.
This Home Isn't Unusual for This Area
Lutherville-Timonium developed heavily through the 1950s and 1960s, which means the housing stock along York Road and the surrounding neighborhoods is full of single-story ranchers, split-levels, and cape cods from the same era. They share a consistent set of building characteristics — and a consistent set of problems.
If your BGE bills feel higher than they should, your first floor is harder to cool than the basement, or your AC runs without ever catching up — the attic is almost always the right place to look before spending money on mechanical upgrades.
- Original 1950s–60s attic insulation that has never been replaced or upgraded
- Whole-house fans standard in this era — typically unsealed and leaking year-round
- Pull-down attic stairs with uninsulated frames and unsealed perimeter gaps
- Single-story construction means no buffer between living space and attic heat
- Basement air handlers pushing conditioned air upward through leaky ceilings
- HVAC equipment at 10–15 years old — often overworked in leaky envelopes
Projected annual energy savings for this specific home, based on the recommended scope and actual audit data
Available BGE rebates for the recommended work — applied directly to project cost by us as an approved contractor
Measured air leakage for this home — significantly above the threshold associated with chronic comfort and efficiency problems
Common Questions About Energy Audits in Timonium
Does Your Timonium Home Have the Same Issues?
If you own a rancher, split-level, or cape cod in Timonium built before 1980 and your AC runs constantly without catching up — an audit is the right first step before spending money on anything else.
BGE-approved contractor · BPI-certified auditor · Timonium & Lutherville, MD · MHIC #165469