Detached garage plans for a permit are a set of drawings that show where the garage goes on your lot and how it will be built. A complete set usually has five to eight sheets: site plan, floor plan, elevations, foundation, framing and roof, and sometimes electrical and details. Getting the set right the first time is the best way to avoid plan review comments, which for garages most often concern setbacks, height, wall bracing and foundations.
Quick answer: Detached garage plans for a permit typically include a site plan with setbacks and coverage, a dimensioned floor plan, elevations showing height, a foundation plan and section, framing and roof plans with header and bracing details, and an electrical layout. Prefabricated or kit garages substitute the manufacturer’s engineered drawings for some sheets.
The sheets in a detached garage plans set
| Sheet | Content |
|---|---|
| Site plan | Lot lines, house, garage footprint, setbacks, driveway, easements, coverage table |
| Floor plan | Dimensions, doors, windows, slab slope, stairs if any |
| Elevations | All four sides, height from grade, roof pitch, materials |
| Foundation plan | Footing and slab dimensions, anchor bolts, thickened edges |
| Building section | Footing to roof: wall framing, insulation if any, roof structure |
| Framing and roof plan | Header sizes, truss layout, bracing panels |
| Electrical plan | Panel or feeder, lights, outlets, opener, GFCI |
| Details | Wall bracing at door, connections, flashing |
Small garages may combine several of these on one or two sheets. Our pillar garage permit guide explains the zoning and code rules each sheet must satisfy.
Site plan
The site plan is checked first. Include the lot dimensions, house, garage, all other structures, setbacks to every line the garage faces, the distance between the garage and the house, easements, driveway and a lot coverage calculation. If the garage is close to the house, the distance may trigger fire separation rules. Our garage permit drawings include a coverage table on the site plan.
Floor plan
Dimension the outside walls, door and window openings, and interior features such as a workbench or stair. Note the slab slope toward the door or a drain, the garage door size, and any service door. If the garage includes a workshop or storage loft, show it. Our floor plans service draws this sheet to permit standard.
Elevations and height
Elevations show each side of the garage, the roof pitch, materials, and the height measured as your code defines it. Accessory height limits are often strict, and how height is measured (to the ridge, the mean roof height or the eaves) can decide whether a design passes. See how building height is measured. Our elevation drawings label the height dimension the way your code measures it.
Foundation
- Footing depth below frost line, width and reinforcement.
- Slab thickness, reinforcement or mesh, vapour retarder where required.
- Thickened slab edges or stem walls.
- Anchor bolts or straps: size, spacing, distance from corners.
- Door openings: how the slab and footing are detailed at the garage door.
Framing, headers and wall bracing
The garage door wall is the critical framing area. A 16-foot door leaves short wall segments either side that must still resist racking. The IRC offers prescriptive bracing methods, including portal frames for narrow walls, and engineered alternatives. Show the header size over the door, the bracing method and panel lengths, and hold-downs if required. Also show the roof truss layout and truss supplier reference, or rafter sizes.
Electrical
Show the power source (a feeder from the house or a separate service), lighting, receptacles with GFCI protection, the garage door opener, and any EV charger or workshop circuits. Note the feeder route and burial depth on the site plan. Many jurisdictions take the electrical permit separately from the building permit.
Optional extras that change the plans
- Loft or storage above: floor framing and load, stairs or pull-down ladder, guard at the opening.
- Bonus room or apartment: habitable space rules and possibly ADU zoning; see our ADU permit guide.
- Plumbing: sinks or bathrooms require plumbing plans and can raise zoning questions.
- Heating: mechanical permit and energy rules if the garage is conditioned.
Kit and prefab garages
For steel or wood kit garages, the manufacturer’s engineered drawings usually replace the framing and roof sheets. You still need a site plan, a foundation designed to match the manufacturer’s anchoring, and electrical information. See metal building permits.
Common plan review comments on detached garages
- Height exceeds the accessory limit, or the measurement method is unclear.
- Setback to the rear or side line not dimensioned.
- Coverage table missing.
- No bracing detail at the door wall.
- Footing depth not tied to frost depth.
- Electrical feeder not shown.
For responding to comments, see how to respond to permit correction comments.
Typical garage sizes
| Type | Typical size |
|---|---|
| One-car | 12 × 20 to 14 × 24 ft |
| Two-car | 20 × 20 to 24 × 24 ft |
| Two-car with workshop | 24 × 30 ft or more |
| Three-car | 30 × 22 to 36 × 24 ft |
Check the size against your accessory size cap and coverage before designing.
Who can prepare detached garage plans
In most states, homeowners, drafters and designers can prepare plans for a residential garage that follows the prescriptive code. Engineering is needed for designs outside the code tables: long spans, large door openings without prescriptive bracing, heavy roof loads, or poor soils. Some jurisdictions require a licensed professional for all accessory buildings above a size; check locally.
Frequently asked questions
What drawings do I need for a detached garage permit?
Usually a site plan, floor plan, elevations, foundation and framing details, and an electrical layout.
Can I use stock garage plans?
Yes, adapted to your lot, frost depth, loads and local code. You still need a site plan specific to your property.
Do garage plans need an engineer’s stamp?
Not usually for prescriptive designs. Long spans, wide openings or unusual loads may need one.
How tall can a detached garage be?
It depends on your accessory height limit and how height is measured. Many codes set limits well below the house height.
Do I need a survey for a garage permit?
Not always. Many offices accept a site plan from the plat, but tight setbacks make a survey wise.
