Installing a new A/C system and wondering about insulation
114-year-old home, no insulation, redwood, plaster and lath, mostly knob and tube. Attic gets extremely hot in summer, despite two attic fans reducing the temperature. Want to make the attic usable year-round as a gym. Need it to be cool enough, around mid-70s for a few hours every few days.
Looking to install an A/C system, but unsure about insulation. The A/C companies we're working with aren't strongly recommending it.
What are the benefits of insulating the attic room (about 600 sq. ft.)? Will it significantly cut cooling costs? Cost is a concern, especially considering future expansion plans in 3 to 5 years.