HVAC in a town built for weekends, not July
Frank Coggins built Berkeley Lake's original cottages in the late 1940s as a fishing and weekend retreat, years before the city incorporated in 1956 — and those cottages weren't built with metro Atlanta's brutal July heat (average high near 91°F, humidity often above 70%) in mind, because nobody was living in them full-time in August.
Sizing a system for full-time living
An HVAC assessment on one of Berkeley Lake's original cottage-era homes should check whether the system was ever upgraded for full-time occupancy, since a unit sized for occasional weekend use often can't keep up with a Georgia summer lived in daily.
Where a Berkeley Lake HVAC call can go
Details that speed up a Berkeley Lake HVAC quote
Let us know if your home is one of the original 1950s cottages, since it may still be sized for occasional use rather than a full Georgia summer lived in daily. Include condition, timing, and access constraints.
A mechanical permit, and maybe an electrical one
Gwinnett County issues the mechanical permit for HVAC work in Berkeley Lake, and a cottage converted from seasonal to full-time use may need electrical work too if the original panel predates year-round living.
See Berkeley Lake HVAC-permitting sources and verification notes.