This house suffered from inadequate ventilation in some rooms, which was so noticeable during the winter months that the air conditioner was often used to reduce humidity and the sense of "stuffiness." A whole-house heat-recovery ventilation system was added, with a priority on ventilating these stuffy rooms, to very good effect.
insulate above-ground wall
Above-ground walls are typically cost-effective to insulate, for a number of reasons:
- they are more exposed to wind than foundation walls are
- they are less solidly built than foundation walls
- until the 1960s, they were usually built without any insulation in them.
Insulating above-ground walls usually involves drilling holes either on the inside or the outside of the wall and blowing cellulose insulation into each wall cavity. Since the cavities are usually only 16" wide and it takes two holes to fill each one, that's a lot of holes. If the holes are outside, they are covered with round plastic caps; when a house already has vinyl siding, these caps may be concealed behind the siding. If the holes are drilled inside, they are covered by a chair rail and crown molding.
The owners of this house had only recently moved in, after renting it to others. The tenants had used the thermostat very frugally so that the heating bills were unusually low and the computer model could not be made to match accurately.
We found a gas leak at the end of an old disconnected pipe where an appliance had been. We recommended removing and recycling the pipe, capping off the junction.
This house had extremely high baseline electricity consumption. Our main recommendation to the homeowners was that they reconsider whether they need to run two full-size freezers, three refrigerators, and a hot tub year-round.
This rural 2-story house was owned by a single mother of two teenagers. She qualified for the Weatherization Assistance Program, so they had come and blown insulation into the attic and replaced the windows, without first sealing air leaks or addressing other major problems with the house. I was very disappointed by the quality of work done by the WAP contractors.
This house presented us with some biological hazards, namely pigeons in the attic and a dead squirrel under the porch! There was also a significant amount of moisture in the crawl space, made worse by batts of insulation that had fallen from the flooring above.
This was one of the leakiest houses we have audited, due mostly to an open ceiling in the mechanical closet. This opening was left to provide make-up air to the natural-draft furnace, but it had the effect of opening the entire house to the attic via the ductwork.
This was a fairly straightforward audit -- the building was in very good shape and only needed air sealing and insulation.
An unusual feature of this house was a second-floor playroom, added on above the back porch in such a way as to be accessible only from a half-height door in one of the bedrooms. This unorthodox design resulted in a valley where the main roof of the house sloped into the wall of the playroom (see photo). This valley creates an opportunity for moisture problems. There was also no ventilation in the bathrooms, and the clothes dryer vented into a crawl space, creating more potential for moisture problems.
The most notable thing we found testing this house was that sewer gas flooded in when we did the blower door test. The floor drain trap had been routed into the sump pump hole so that the trap was always empty, allowing gas to enter the house from the sewer. The owner had the sump pump replaced immediately after our visit, and the problem was fixed.
This home proved a real challenge to model, since it had four gambrel roofs of differing sizes and two separate basements, each with its own furnace and water heater! Although the heating and cooling equipment was quite old, the heating bills were unusually low due to extremely frugal use of the thermostat, which is great, but it left little room for improvement! In fact, one of the furnaces had not been used at all in the previous winter, and the temperature in that part of the house was below 60˚F.
This house was in good shape overall, but it was significantly lacking in ventilation and had many moisture sources (including an untrained puppy), so we strongly recommended adding controlled ventilation while sealing air leaks. There was nearly twice as much air leakage as necessary, most of it from the hatches between the finished attic and the kneewall areas. The window frames also leaked quite a bit, and we were pleased to be able to recommend new windows (or repairing the old ones) as a cost-effective measure.