The House Stats
The house clocks in at 3,937 square feet. At 1,524 square feet, the original footprint is quite modest, with three bedrooms and two baths on the main level. But prior owners finished a covered porch, enclosed a three-seasons room over the entire two-car garage and, you guessed it, finished the full basement into a carpeted mold farm—more commonly known as a family/recreation room—a freezing cold and moldy bathroom and laundry, and two large, subterranean bedrooms.
As one might expect, while one of the prior owners did partially install an interior perimeter drain to deal with bulk water intrusion, there was no effort to control moisture diffusion behind the furred-out drywall and below the carpet pad. The real estate agent seemed to think that this finished basement was a real selling point. We just groaned.
The house was a short sale—sold “as is”—or, in other words, a never-ending nightmare of things failing and breaking. The systems were a rusty mess: there was a natural gas leak, gutters falling off, copper piping with pinhole leaks about to explode, two macerating ejector pumps leaking sewer gas, and a few overloaded circuits here and there.
In addition to these system failures, the classic 1954 aesthetic had been covered by six-panel faux colonial doors, bronze light fixtures, dark paint, and 1990s-dated bathroom and kitchen updates. What had once been a well-tended landscape was now overgrown with English ivy. And, for better or worse, it had a swimming pool with a leaky pump and broken valves, guzzling tons of chemicals.
So why did we buy such a money pit? The house was once a lovely example of mid-century modern residential architecture. The furniture we have collected over the years is all vintage 1950s to ’60s Danish modern; we lean toward Japanese detailing, simplicity, and textures. And we love drinking bourbon out of roly-poly glasses. I drove by this house every day for three years, and at least once a week for 12 years prior. We’ve always loved its uniqueness and lines. When you go inside and see the stone fireplace slicing through a wall of glass with a cathedral ceiling, you’re in genuine mid-century modern design heaven. It also has made a great family home and blank slate for testing and showcasing our ideas for residential retrofits and lawn rewilding.
Existing Conditions
Oversized HVAC Systems
When we first visited the house, it was clear that the furnace and air conditioner (AC) were in tough shape, and the previous owner had disclosed that the mechanicals were only 50% operational. We knew these systems would need to be replaced soon but did not understand the full extent of the problems, nor the urgency with which we would be forced to deal with them.
The original house had two gas furnaces, each rated at 80,000 Btu/h, and about five tons of AC. These systems served a single-zone duct system. Two furnaces and a one-zone duct system? Yup. It was one strange setup.
The addition over the garage was graced with another 50,000 Btu/h furnace and 2½ tons of cooling. With a total of 210,000 Btu/h of heat and 7½ tons of cooling, you might think that we had no problem staying comfortable … but you would be wrong!
Finally, the water heater was a standard-issue gas water heater with a hopelessly rusted flue that was sagging and spilling combustion fumes.
Windows from the 1990s
The windows were Andersen double-pane windows with fiberglass frames from the early 1990s and were definitely starting to show their age. A few window seals were broken and several had non-functioning latches that would not properly close.
There was also a very strange phenomenon that we have never seen before. On a handful of windows, condensation formed in a tidy oval in the middle of the window on the interior surface. Between this very common (in our house) but unusual occurrence, some wavy vinyl siding, and a trash can lid that literally melted on a spring day, we deduced that the window panes were bowing in towards one another, creating concave mirrors for melting the plastic siding and trash-can lids, resulting in colder temperatures at the center of glass rather than at the perimeter!
Air leakage
As one would expect, the house was the furthest thing from airtight. We logged 5,250 cubic feet per minute at 50 pascals of pressure during our blower-door test. In a fascinating twist, the utility incentive program would reward us for improvements, but the auditors and home energy improvement contractors are instructed to recommend cut-and-paste improvements that leave tons of energy and money on the table.
The audit suggested, for example, that our house was 1.27 times leakier than it should be to allow “for proper ventilation!” Air sealing as per the audit recommendation would have only reduced our air infiltration to 4,200 cfm. We have designed and delivered houses almost this large that tested out at 200–300 cfm, around 0.3 ACH50. Needless to say, we went above and beyond these air sealing recommendations, which was absolutely essential to us achieving the energy cost savings that we did. The incentives, while helpful, are not commensurate with our increased ambitions—and unfortunately could mislead some homeowners into doing less than what would be truly effective.
A Big Mold Problem in the Basement
From our first inspection, we knew there was a mold problem in the basement, but we did not know the extent of it. And, that was not the only air quality challenge. High levels of air infiltration and exfiltration combined with frame assemblies built on top of concrete slabs exposed to the exterior (sunroom and garage addition) resulted in focused areas of condensation-related moisture and its biological consequences. Poorly installed and maintained gutters and downspouts and typically poor window installation details led to some problems with bulk water entry into the basement.
