How to Build a Garden Shed Guide for Eastern Washington Homeowners & Contractors

Do You Need a Permit? Start Here Before You Buy a Single Board

Every shed project we help plan at Builders Supply starts with the same question: “Do I need a permit for this?” It’s smart to ask first, because permit rules will shape your size, placement, and even your foundation choice before you ever pick up a hammer.

In most Eastern Washington jurisdictions — including areas around Spokane, Stevens County, and the rest of our service area — a common rule of thumb is that accessory structures 200 square feet or smaller may be exempt from a building permit. That’s roughly a 10×20 or 14×14 footprint, which covers a lot of typical storage sheds. But “exempt from a permit” does not mean “exempt from the rules.” You still have to follow:

• Setback requirements — how close the shed can sit to your property line, usually measured in feet from the rear and side boundaries.
• Easement restrictions — utility, drainage, or access easements can prohibit a structure even if the setback distance would otherwise allow it.
• Height limits — many jurisdictions cap permit-exempt sheds around 12 feet at the peak.
• Drainage requirements — your roof runoff generally has to stay on your own property, not shed onto a neighbor’s lot.

Once you go over that 200 sq. ft. threshold, add a second story, heat or cool the space, or plan to use it for anything beyond storage or a playhouse-type use, you’re almost always looking at a permit and a plan review. The same goes if you’re adding electrical service — running power to a shed often triggers Washington State Energy Code compliance, even on a small structure.

Check Before You Design, Not After

The biggest mistake we see is homeowners designing the whole shed first, then calling the county. Flip that order. A quick call to your local planning department (Spokane County, Stevens County, or your specific city) before you finalize dimensions can save you from redesigning a shed that’s already framed, or worse, having to move one after it’s built.

Choosing the Right Foundation for Eastern Washington Ground

This region gives sheds a rough ride. We get real winter freeze-thaw cycles, dry compact soils in the summer, and enough snow in Colville and Kettle Falls that ground movement is a real concern. The foundation you choose has more to do with your shed’s long-term performance than almost any other decision you’ll make.

Common Foundation Options

• Compacted gravel pad — Our most-recommended base for small to mid-size sheds. A 4-6 inch bed of compacted crushed gravel drains well, resists frost heave better than bare soil, and gives you a stable surface for skids or pier blocks.
• Pressure-treated skids — Set on gravel or concrete piers, skids let air circulate under the floor and are easy to level or re-level later. Good for prefab and kit sheds.
• Concrete pier blocks — A step up from skids alone, piers lift the structure further off the ground and work well on slightly uneven sites.
• Poured concrete slab — The most permanent option and the best choice if you’re planning a workshop, heavy equipment storage, or eventual electrical/heating additions. Slabs need to be below frost depth or properly designed for our freeze-thaw conditions, so this is where we often recommend talking to a contractor.
• Bare soil — We don’t recommend this. Direct ground contact invites rot, pest issues, and uneven settling, especially once winter moisture works its way underneath.

Drainage Comes First, Always

Before you set any foundation, grade the site so water moves away from the shed, not toward it. In the Spokane area and up into Colville and Kettle Falls, spring snowmelt is often the real test of a shed’s foundation — not the summer thunderstorms. A pad that’s raised even 2-3 inches above surrounding grade, with gravel that lets water percolate through rather than pool, will save you years of maintenance headaches.

Building for Snow Load, Wind, and Freeze-Thaw Cycles

Eastern Washington isn’t a one-climate region — Airway Heights and the Spokane area see moderate snow loads most winters, while Colville and Kettle Falls regularly deal with heavier accumulation and colder sustained temperatures. Whatever your exact location, your shed needs to be built for real snow, not just rain.

Roof Pitch and Framing

A steeper roof pitch sheds snow more effectively and reduces the load your trusses or rafters have to carry. For prescriptive stick-built sheds, dimensional lumber sized for local snow-load requirements matters more than most DIYers expect — undersized rafters can sag or fail after a heavy winter. If you’re building anything with a non-standard span or an open interior (like a shed doubling as a workshop), engineered trusses are worth the extra cost.

Anchoring Against Wind

Lightweight prefab and metal sheds are especially vulnerable to wind uplift, and our region gets its share of strong seasonal gusts, particularly in more open, rural properties around Colville and Kettle Falls. Proper anchoring — whether that’s auger anchors into soil, straps tied into a concrete foundation, or hurricane ties at the rafter connections — is cheap insurance against a shed that shifts or tips in a windstorm.

Handling Freeze-Thaw Movement

Ground that freezes and thaws repeatedly through the winter can heave shallow foundations. This is exactly why we push customers toward gravel pads, piers, or slabs set with frost conditions in mind, rather than sheds set directly on soil. If your foundation moves even half an inch unevenly, you’ll see it in sticking doors and racked walls within a season or two.

Materials That Hold Up in Our Climate

Once your foundation and framing plan are solid, material choice determines how well your shed ages over the next 10, 20, or 30 years.

Framing and Structural Materials

• Pressure-treated lumber for any skids, sills, or posts in ground contact or close to grade.
• Dimensional SPF framing lumber sized appropriately for your roof’s snow-load requirements — don’t guess here, especially for larger spans.
• OSB or plywood sheathing for walls and roof decking; plywood tends to handle moisture exposure slightly better during construction if you get caught by weather before it’s covered.

Exterior Protection

• Housewrap and flashing at all wall penetrations, window and door openings, and roof-to-wall transitions. This is cheap material that prevents expensive rot later.
• Architectural shingles or metal roofing — metal roofing sheds snow more readily and holds up well to UV exposure through our long, sunny summers. Shingles are a lower-cost option that still perform well if properly installed with adequate underlayment.
• T1-11, engineered wood siding, or metal cladding for exterior walls. Metal siding requires the least long-term maintenance; wood siding gives you a more residential look and is easier to modify or repaint later.
• Corrosion-resistant fasteners and structural connectors — hot-dipped galvanized or coated fasteners matter more here than people think, especially with our freeze-thaw moisture cycles working on any exposed metal.

Floor Systems

If you’re building a raised floor rather than a slab, use pressure-treated joists and rim boards with a proper moisture barrier between the framing and your plywood subfloor. This detail is easy to skip and hard to fix once the walls are up.

Prefab, Kit, or Stick-Built: Which Approach Fits Your Project?

We get this question constantly at all three of our locations, and the honest answer is “it depends on your site, your timeline, and your budget.”

Prefab Sheds

Best if you want speed and predictable pricing. A prefab shed can be delivered and set on a prepared pad in a single day. The tradeoff is less customization and sometimes lighter-duty materials that need upgraded anchoring for our wind and snow conditions.

Kit Sheds

A good middle ground for DIYers. Pre-cut components speed up assembly while still letting you build it yourself, control quality of materials, and make small modifications as you go. This is one of the most popular paths for customers building their first shed.

Stick-Built, Site-Built Sheds

The right choice if you want a custom footprint, better integration with an existing structure, or a build that can be upgraded later with insulation, wiring, or extra window/door openings. This approach costs more in labor and time but gives you the most flexibility — especially valuable if there’s any chance your “storage shed” becomes a workshop down the road.

Matching the Build to Its Future Use

Ask yourself now: is this shed only for lawn equipment and garden tools, or might it become a workshop, a small studio, or a place to store an ATV or snowblower with a workbench? If there’s any chance of “beyond storage” use, oversize your framing, plan your door openings wider, and consider a foundation that could support future electrical or insulation upgrades. Retrofitting a shed after the fact is almost always more expensive than building in that flexibility from day one.

What Actually Drives Shed Costs in Eastern Washington

There’s no single number that fits every project, but the cost drivers are consistent:

• Size — cost per square foot often drops as size increases, but total cost obviously climbs.
• Foundation type — a gravel pad is far cheaper than a poured, frost-protected slab.
• Prefab vs. site-built — prefab tends to be more predictable; site-built gives more control but costs more in labor.
• Roofing and siding choices — metal roofing and siding cost more upfront but need less maintenance over the shed’s life.
• Doors and windows — every opening adds framing, flashing, and material cost.
• Site access and grading — this is the most commonly underestimated cost. If delivery trucks or equipment can’t easily reach your build site, or your yard needs significant grading, budget extra.
• Permits and inspections — required once you’re above the local exemption threshold or adding utilities.
• Electrical, insulation, or HVAC — these can roughly double your effective cost per square foot compared to a simple unheated storage shed.

The hidden cost most homeowners miss is site prep. A poorly graded, poorly drained base might save you a few hundred dollars upfront, but it can cost you far more a few winters later in foundation repair, door realignment, or floor rot. In our climate, spending a little more to get the base right the first time is almost always the better investment.

Common Mistakes We See Eastern Washington Homeowners Make

• Assuming small means unregulated. Setback and easement rules apply even to permit-exempt sheds.
• Building too close to the property line without checking local setback distances first.
• Skipping proper drainage and base prep, which leads to rot, settling, and doors that won’t close right by year two.
• Undersizing framing lumber for local snow-load conditions, especially on wider spans.
• Ignoring roof pitch, leaving too shallow a slope for effective snow shedding.
• Not planning for equipment access — a shed that looks great but has a door too narrow for a mower or ATV isn’t doing its job.
• Adding power or heat after the fact without checking whether that retroactively triggers permitting or energy code requirements.
• Setting the shed directly on bare soil in a region with real freeze-thaw movement.
• Underestimating wind anchoring, particularly with lightweight metal or kit sheds on open rural lots.

DIY or Hire a Pro? A Practical Way to Decide

DIY Makes Sense When:

• You’re building a small, simple storage shed under your local permit-exemption size.
• You’re comfortable with basic carpentry and can build or hire out a level, well-drained base.
• The shed is for storage only — no plumbing, wiring, or occupancy planned.
• You’re working from a kit or a straightforward stick-built plan.

Hire a Professional When:

• Your shed is over 200 sq. ft. or otherwise triggers a permit in your jurisdiction.
• You need engineered trusses or a non-standard structural design.
• You’re adding heating, cooling, wiring, or plumbing.
• Your site is sloped, tight, near an easement, or has drainage complications.
• You want stronger assurance around snow and wind performance, or a warranty on the finished structure.

A simple rule that holds up across most of our customer base: DIY works well for small, simple storage sheds on easy sites. Bring in a contractor once size, utilities, site conditions, or code complexity start stacking up.

Whatever route you take, we’re here to help you get the materials right the first time. Builders Supply & Home Center stocks pressure-treated lumber, fram