A site-built wood garage costs more than a kit but is the easiest to match to a house, insulate, convert later and brace for earthquakes. Kits, metal buildings and pole barns cost less up front and suit rural lots. A carport is the lowest-cost cover. Below, each one compared, with HomeGuide's national figures.
Every dollar figure on this page is a national figure published by HomeGuide, not a quote from us. HomeGuide publishes no garage price for Santa Rosa or for California, so we do not claim one. Clay soil, slope, fire zone rules, seismic bracing and access all move the price of a garage here. Figures read on HomeGuide in October 2026.
Is a metal or prefab garage kit cheaper than a stick-built garage?
Yes, up front. HomeGuide's modular garage page lists a prefab 2-car garage at $7,200 to $26,000 for the unit only, or $11,000 to $37,500 with foundation and assembly, against $25,000 to $60,000 for a custom-built two-car on its build a garage page. Garage kits alone run $2,000 to $20,000 for materials. HomeGuide's metal building page puts a prefab metal 20 x 20 garage at $11,000 to $30,000 installed. A kit still needs a permit, a slab, footings and anchors that meet California's seismic rules, which closes some of the gap.
Is a steel garage as durable as a wood-framed one?
Steel lasts well and does not rot or feed termites, which are a real problem in Sonoma County wood. A wood-framed garage lasts just as long when it is kept dry, sits on a proper foundation and is painted. Steel can dent and, without insulation and vapor control, drips condensation on cold mornings. HomeGuide's outbuilding page lists condensation control at $1 to $3 per square foot. Wood is easier to insulate, finish, add windows to and later convert into a unit.
Pole barn garage or stick-built: which is right?
A pole barn, also called post-frame, sets heavy posts in the ground instead of building walls on a full foundation. HomeGuide's pole barn page lists $15 to $40 per square foot installed, against $25,000 to $60,000 for a standard 2-car stick-built garage on the same page. A 24x24 pole barn runs $8,600 to $23,000 there. Pole barns suit rural parcels near Kenwood, Sebastopol or Glen Ellen for equipment and trailers. In town, a stick-built garage is the usual choice because it is easier to match, insulate and permit.
Should I build a carport or a garage?
Build a carport if you mainly need shade and rain cover on a small budget; build a garage if you want security, storage, a workshop or a future unit. HomeGuide's carport page lists a single-car carport at $2,000 to $7,200 installed and a double at $3,200 to $12,000. A garage costs many times that, but it locks, it keeps dust and pollen off, and it can hold a lot more.
Can a carport be enclosed into a garage later?
Yes, if its posts, roof and slab are sound and the spacing allows a door. HomeGuide's carport-to-garage page lists a typical conversion at $10,000 to $40,000, with a 2-car at $20,000 to $40,000. Many carports were built on thin slabs without footings under the posts, so the slab edge may need new footings before walls go on. The same page lists permit fees for this job at $500 to $3,000.
Can I add a garage to a house that has none?
Yes, you can add a garage to your house if the lot has room inside the setbacks and a way for a car to reach it. Many Santa Rosa homes from the 1940s and 1950s were built with no garage or with a carport. A detached garage at the back of a long driveway is often the simplest fit; an attached one needs room at the side. HomeGuide publishes no figure for adding a new attached garage to an existing house as its own item.
Can a detached garage have a bathroom and plumbing?
Yes. A bathroom in a detached garage needs a drain line to the sewer or septic, water, a vent and often a permit review for use. HomeGuide's detached garage page lists plumbing at $450 to $1,800 per fixture. The drain must run downhill to the main line, so the slab height and the distance to the house matter. If you might turn the garage into a unit later, put sleeves for drain and water in the slab now.
What does a workshop garage need?
A workshop garage needs more power, more light, good ventilation and a floor that can take heavy tools. Plan a subpanel and enough circuits for a table saw, a compressor or a welder. Add windows or skylights for daylight and a side door. In Santa Rosa's warm summers, a window on each side or a vent fan helps. A thicker slab under heavy machines and a wide door for bringing in lumber are worth planning from the start.
Want a number for your own lot? We visit, measure and check the rules, then put the scope and price in a written quote. Call or text (707) 392-2557.