garage door handle

Building a Detached Garage

What permits are required?

  • Building permits are required for detached garages. If you are building an attached garage, please contact the Inspections Department for specific information. Submit an application and two sets of your building plans to the City of Hopkins Inspections Department. Building permits for garages will typically be processed within 5 business days of receiving a complete set of plans.
  • If you will be installing a heating or air exchange system in your garage, you will also need a mechanical permit.
  • For any electrical work being done, you will need an electrical permit.
  • If you will be installing any plumbing, you will need a plumbing permit.


It is the responsibility of the permit applicant to call the Inspections Department to arrange for the inspections. Advance notice of 24 hours is required. Three inspections are usually required for the construction of a garage. They are:

  • Slab Inspection - To be made after all formwork and reinforcing is in place but prior to the pouring of concrete.
  • Framing Inspection - To be made after all framing and bracing is complete, rough electrical (if any) is approved, but prior to the application of siding or roofing.
  • Final Inspection - To be made upon completion of the garage and grading is complete.

You will also need inspections if you have applied for permits in addition to your building permit.

Code requirements for detached garages

The State of Minnesota has updated the building code effective January 24, 2015. We are in the process of reviewing our website to make sure everything is up to code, but you should always review the State of MN Building Code before beginning any project.

Size and Location

City zoning ordinances regulate the size and location of detached residential garages. The following is a brief overview of these regulations. Please contact the Zoning Administrator at 952-548-6342 for specific requirements.

  • Detached garages must be located 6 feet minimum from the dwelling.
  • A three-foot side and rear yard setback is required.
  • If the drive-in door faces a street or alley, the garage must be set back 20 feet from the property line.
  • The lot coverage requirements vary depending on the zoning district where your home is located. Please contact the Zoning Administrator for specifics.
  • The height of the garage is limited to 15 feet measured to the midpoint between the eave and the peak of the roof.


Detached garages may be constructed on a thickened-edge floating slab. The makeup, characteristics, placement, finishing, and maintenance of concrete involve many factors too lengthy to be covered here. For an in-depth review of concrete, please read one of the many excellent books on the subject available at local building centers and bookstores. There are also many good websites that provide helpful information.

If you are constructing an attached garage, the foundation must extend at least 42 inches below finished grade. Contact the Inspections Department for specific requirements for attached garages.

Sill Plates & Anchor Bolts

Sill plates must be 2" nominal thickness and at least as wide as the wall studs. When plates rest on a concrete slab in contact with the ground, or when they rest on a masonry or concrete foundation wall and are less than 8" from exposed ground, they must be pressure preservatively treated or decay-resistant wood such as redwood or cedar.

Sill plates must be anchored to the foundation or slab with ½" anchor bolts that extend a minimum of 7" into the foundation or slab. A nut and washer must be tightened on each bolt to the plate. Anchor bolts must be spaced not more than 6' on center and must also be located within 12" from the ends of each plate section.

Approved foundation anchors may be used in place of the bolts when installed in accordance with the manufacturers installation instructions.

Wall Construction

Walls may be framed with minimum No. 3 grade 2x4 lumber spaced 16 or 24 inches OC. Utility grade studs may be used when supporting only a roof and spaced not more than 16 inches OC.

Wall studs are limited in height by the following:

  • 2x4 16 inches OC - 12 feet
  • 2x4 24 inches OC - 10 feet
  • 2x6 16 inches OC - 18 feet
  • 2x6 24 inches OC - 16 feet

Walls must be capped with a double top plate installed to provide overlapping at corners. End joints in top plates must be offset at least 24 inches.

Exception: A single top plate may be used provided the plate is adequately tied at joints and corners by a minimum 3-inch-by-6-inch by 0.036-inch-thick galvanized steel plate that is nailed to each wall segment with six 8d nails on each side and provided that rafters or trusses are centered over the studs with a tolerance of no more than 1 inch.

When rafters or trusses are spaced 24 inches on center and wall studs are spaced 24 inches on center, rafters or trusses must bear within 5 inches of the studs beneath.


Openings in exterior walls must be provided with headers. The size of the header will vary based on the width of the opening, the orientation of the roof framing, and the span of the roof-framing members. As a general rule, the following header sizes are acceptable:

  • For openings not exceeding 3'6" - (2) 2X4's on edge (one cripple stud each end)
  • For openings not exceeding 5'0" - (2) 2X6's on edge (one cripple stud each end)
  • For openings not exceeding 9'0" - (2) 2X12's on edge (two cripple studs each end)
  • For openings exceeding 9'0" - an LVL header is required

For information on garages with roof spans greater than 24 feet or for specific information on your garage design, contact the Inspections Department. For information on LVL headers, contact the LVL supplier.

Wall Bracing & Sheathing

Walls are required to be braced by one of the following methods:

  • Nominal 1x4 continuous diagonal braces let in to the top and bottom plates and the intervening studs or approved metal straps installed in accordance with the manufacture's specifications. Braces must be installed at an angle not to exceed 60 degrees or less than 45 degrees.
  • Wood structural panel sheathing not less than 5/16 inch for 16-inch stud spacing and not less than 3/8 inch for 24-inch stud spacing. Sheathing must be attached with a minimum of 6d nails at 12 inches OC.
  • ½ inch fiberboard sheathing applied vertically on studs spaced 16 inches on center. Sheathing must be attached with 1 1/2 inch galvanized roofing nails, 6d common nails, or 16 ga 1 1/2 inch staples spaced 3 inches OC around the perimeter and 6 inches OC on intermediate studs.

Wall Sheathing

The code does not require that walls be sheathed if let-in bracing is used. However, some siding is not permitted to be installed except over sheathing. Examples of this include aluminum, steel, and vinyl siding. If you will not be applying wall sheathing to your garage walls, be sure that the design is compatible with the siding material you will be using. Please contact the Inspections Department for further assistance.

Eave Projections

Eaves may project no closer than 2 feet from a property line that abuts another property. If you desire a 2 foot eave around your garage, the garage must be placed at least 4 feet from the property line. Eaves may not project beyond the alley line.

Roof Trusses

Wood trusses may be used as long as they are designed to meet state snow load requirements. Truss design drawings must be provided that include:

  1. Slope of roof, span and spacing.
  2. Location of all joints.
  3. Required bearing widths.
  4. All applicable design loads.
  5. Lumber size, species and grade for each member.
  6. Connection requirements for:
    1. Truss to truss girder.
    2. Truss ply to ply.
    3. Field splices.
  7. Calculated deflection ratio and/or maximum description fro live and total load.
  8. Locations of all bracing and size of braces required by the design.

Be sure to adequately secure the trusses to the top wall plate. Inexpensive metal connectors are available that are easy to use and provide a more secure attachment than toenails.

Never cut, notch, splice, or alter any portion of a truss except the tails of the truss without specific instructions from the truss designer.

Trusses typically require diagonal bracing at each end of the building and lateral bracing along the bottom cord.

Field Framed Rafters

If you wish to field frame your roof, please contact the Inspections Department for assistance due to the large number of variables involved with roof framing.

Roof Sheathing

Roofs may be sheathed with either lumber sheathing or wood structural panel sheathing. Because lumber sheathing is rarely used, it will not be covered here.

Following are some examples of some acceptable sheathing applications:

Span Rating
Panel Thickness
Maximum Span in Inches
w/Edge Support
w/o Edge Support
15/32 or 1/2
19/32 or 5/8
  • Panels must be continuous over two or more spans and be installed with long dimension perpendicular to supports.
  • Edge support may be tongue-and-groove joints, panel edge clips, lumber blocking or another approved supports.


For information on the various fastener requirements, please download Fasteners.


For information on wall coverings such as stucco, EIFS, masonry, veneers, or wood shakes and shingles, please contact the Inspections Department.

Weather-resistant sheathing paper is not required unless required by the siding manufacturer.

Siding Material Nominal Thickness Joint Treatment
Horizontal Aluminuma Without Insulation 0.019b
With Insulation 0.019 Lap
Brick veneer
2 Contact Inspections
Concrete masonry veneer 2 Division
Hardboard Panel siding - vertical 7/16 c
Hardboard lap siding - horizontal 7/16 c
29 ga. Lap
Stone veneer 2 Contact Inspections
Particleboard panels 3/8 - 1/2 c
5/8 c
Plywood panelsd (exterior grade) 3/8 c
Vinyl siding 0.035 Lap
Woode rustic drop siding 3/8 Lap
Shiplap 19/32 Average Lap
Bevel 7/16 Lap
Butt tip 3/16 Lap

a Aluminum nails must be used with aluminum siding.

b May be unbacked only when the maximum panel width is 10 inches and the maximum flat area is 8 inches.

c If boards or panels are applied over sheathing or a weather-resistive membrane, joints need not be treated. Otherwise, vertical joints shall occur at studs and be covered with battens or be lapped.

d 3/8 inch plywood cannot be applied directly to studs space greater than 16 inches o.c. when long dimension is parallel to studs. 1/2 inch plywood cannot be applied to studs spaced greater than 24 inches o.c. The stud spacing shall not exceed the panel span rating provided by the manufacturer unless the panels are installed with the face grain perpendicular to studs or over sheathing approved for that stud spacing.

e Woodboard sidings applied vertically shall be nailed to horizontal nailing strips or blocking set 24 inches on center. Nails shall penetrate 1 1/2 inches into studs, studs and wood sheathing combined, or blocking. A weather-resistant membrane shall be installed weatherboard fashion under the vertical siding unless the siding boards are lapped or battens are used.

All siding materials must be installed according to the manufacturer's written instructions.

For fastening siding materials, download Fasteners.


For information on roofing, see roofing.

Garage Door Openers

State law requires that all automatic garage door openers sold and installed be equipped with an automatic reversing device. This means that the door must have a means to reverse the closing function if something is detected in the path of the door.


  • Administrative Assistant

  • For information specific to setbacks:
    City Planner