An attic over 130°F costs you $400 a summer. Here is the fix.
The summer math
A poorly ventilated Evanston attic regularly hits 145–160°F during July afternoons. That heat radiates down through even well-insulated ceilings and adds 15–25% to your central AC runtime. On an average Evanston cooling bill of $190/month June through August, that is $85–$140 per month in avoidable cost — $250–$400 over a single cooling season.
The winter math
The same poor ventilation that bakes the attic in summer drives ice damming in winter. Repeated ice-dam repair bills run $1,500–$5,000 per event. We see homes that have spent $20,000 on ice-dam-related interior repairs over a decade — and never paid the $6,000 it would have taken to fix the attic.
The fix
Continuous soffit intake, continuous ridge exhaust, R-60 cellulose insulation with air sealing of every ceiling penetration. Typical project cost $4,800–$7,500. Eligible for IRA 25C tax credit (up to $1,200 for insulation, additional credits for air sealing components).