Back in the early 1990s, before I joined the construction industry, I was taking college business classes. I remember learning how to assess a business using SWOT analysis. The acronym stands for strengths, weaknesses, opportunities, and threats. I’ve been applying this idea—with emphasis on weaknesses and threats—to the assessment of homes that are about to undergo renovations. I find the SWOT theory helpful for gathering data, determining scope of work, and developing a project plan.

I think it’s best practice to assess a home’s “strengths” and “weaknesses” before starting any renovations. When I work in existing homes, typically the owner’s goals include improving the structure, increasing energy efficiency, and elevating comfort levels. On occasion, the changes made do not have the expected outcomes and, in some instances, have damaged the structure or endangered the occupants.

A case example

Back in the early 2000s, I was hired to replace a shingled roof with a new metal roof. The job went well—both the homeowner and I were pleased with the outcome. The following year, I was asked to replace a few upper-level windows in the same house. The windows would not seal, and a woodpecker had made a hole in one that completely penetrated the wood frame. This job also seemed to be a success; continuity of the water control layer was improved and air leakage on the upper level was reduced.

The following spring, however, the homeowner told me there was a roof leak; water was dripping through the finished ceiling in several locations. When I arrived, I found the entire underside of the roof sheathing full of frost. The melting frost was the source of the water leaks. So, what changed to cause attic frost to form? The installation of new windows!

Attic…