Your attic estimate, online

How the range is worked out

The estimator does not guess. Every line in it is a spread that Bay Area contractors and cost guides publish for that kind of work, collected on October 14, 2026. Nothing in it is an Attic WISE price list: we don't have one online yet, so we show you what the market charges instead.

Work priced by area is multiplied by the attic size you enter. Taking out old insulation runs $1 to $3 per square foot in the published Bay Area figures, and blown-in insulation runs $1.20 to $4.50 per square foot. One-off jobs, like air sealing or closing rodent entry points, use the typical job range for that work. The estimator adds up all the lows, adds up all the highs and rounds both out to the nearest $50.

A few rules shape the number:

• Thin insulation is priced like a new install. HomeGuide prices topping up the same as starting from bare joists, so there is no discount for what is already there.
• Old, dirty or rodent-damaged insulation comes out first. Removal is added for those answers, and rodent damage also adds a cleaning and sanitizing job.
• Small attics hit a floor. Some companies have a minimum charge of $1,500 to $2,000, so the top of the insulation line never drops below $2,000.
• Crawl spaces borrow your attic size. Both sit over the same footprint; the inspection measures the real area.

Adding every high end together overstates the top of a long list, because a job rarely lands at the top price on every line. Treat the top of a big bundle as a ceiling, not a forecast. Every range and its sources are on the cost page.

What the free inspection covers

We go up through your attic hatch and measure how deep the insulation really is. Then we look at the things that move the price: gaps around the top plates, wires and light fixtures, any sign of rodents, how air gets in at the eaves and out at the roof, and the condition of any ducts running through the attic. Before we leave, we talk you through what we found. The attic inspection guide has the full checklist.

After the visit you get a written quote: what comes out, what gets sealed, what goes in and how deep. The materials carry the manufacturer warranty.

Rather not have a visit?

Pick "Estimate from photos or video" instead. The page after you send the form lists what to photograph: the hatch, a wide shot of the attic floor, a tape measure standing in the insulation, and anything that worries you. Only go up if you can do it safely, stepping on the joists and never between them. If the photos can't answer something, we'll suggest a visit.

Renting?

You can still ask for an estimate. The property owner has to approve the work before anything is installed, so bring them in early. A written quote is easy to forward to an owner or a building manager.

What we don't handle ourselves

Some things in an attic need a different trade. If you see gray-brown, pebble-like fill, it may be vermiculite, which the EPA says to treat as if it contains asbestos and leave undisturbed. Tell us in your notes and we'll point you to an asbestos consultant. Old knob-and-tube wiring goes to an electrician before insulation goes near it.

If you find rodent droppings, please don't sweep or vacuum them; California's public health department advises against it (why). Choose "Rodent damage" in the estimator and we'll take it from there.

Where we work

We work in homes across Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara and Sonoma counties, from a base in Redwood City. If your ZIP code isn't obviously in one of them, the estimator still works: send the request and we'll confirm we can get to you. Prefer to ask first? The contact page has every way to reach us, and the services page explains each kind of work in the range.