Site Prep 101: How to Prepare Your Land for Tiny House Delivery

The tiny house arrives on a truck. The truck backs into your property. Someone unhooks the trailer, lowers the jacks, and drives away. What happens in the three months before that moment determines whether you move into a comfortable, functional home or discover — too late — that you have no power pedestal, a site that drains into your subfloor, and a driveway that wasn’t wide enough for the delivery vehicle.

Site preparation is the part of the tiny house journey that gets the least attention and causes the most expensive surprises. Most buyers focus on model selection, financing, and interior design. Site prep — the clearing, grading, foundation work, utility trenching, and access route planning that has to happen before delivery — often gets treated as an afterthought. It shouldn’t be.

This guide covers every layer of site preparation, whether you’re placing a tiny house on wheels (THOW) on a gravel pad or installing a permanent modular home on a concrete slab. The requirements are meaningfully different, and the most common mistake is applying the wrong standard to the wrong situation. Before you plan your site, also check what your local jurisdiction requires in our 2026 ADU regulations guide — permit requirements vary significantly by state and county.

THOW vs. Fixed Foundation: Two Completely Different Site Preps

The single most important question in site preparation is: will this home be mobile or permanent? The answer determines the foundation type, the permit requirements, the utility connection standard, and what happens to the site if you ever move the structure. Getting this wrong — prepping a permanent foundation for a THOW that will eventually move, or treating a permanent placement like a temporary parking job — creates expensive problems later.

MagicBox THOWs ship with ANSI A119.5 certification and DOT-approved trailer frames, which means the home itself meets the regulatory standard for mobile placement — your site prep just needs to provide a stable, level surface and appropriate utility connections. For permanent placements, the foundation standard is set by your local jurisdiction’s residential building code. Our ADU regulations guide covers state-by-state requirements in detail.

Clearing, Grading, and Drainage

Before any foundation material goes down, the site needs to be clear, level, and set up to drain away from the home. These three elements — clearing, grading, and drainage — are where the majority of site prep failures originate, because they’re the least visible and the easiest to underestimate.

Clearing

Remove all vegetation, roots, and organic material from the footprint area and at least 3 feet around it. Organic material under a foundation compresses and decomposes over time, causing uneven settling. Tree roots that remain under a gravel pad will continue growing and can displace the pad surface or penetrate utility lines. Clear to bare mineral soil before any compaction work begins.

If there are trees near the intended site, check their root spread — a mature tree’s roots typically extend to 1.5× its canopy diameter. Roots under a gravel pad won’t stop growing; they’ll find the moisture and organic material your gravel retains. Place your site clear of major root zones where possible, or plan for root barriers.

Grading

The pad surface needs to be level to within ±1 inch across the entire footprint. A tiny house that sits on an unlevel pad places constant lateral stress on the trailer frame and can cause door and window frames to rack over time. Use a laser level during pad preparation, not just a spirit level — you need to check level across the full length and width of the home, not just at one corner.

The surrounding grade should slope away from the home at a minimum of 2% (roughly ¼ inch per foot) in all directions to direct stormwater away from the foundation area. Flat or inward-sloping sites pool water under and around the home, which accelerates corrosion, promotes mould under the floor system, and can cause the pad to shift over winter freeze-thaw cycles.

Drainage

For sites with clay-heavy soils or poor natural drainage, a perforated drain pipe (French drain) around the perimeter of the pad is worth the investment. Run it to a daylighting outlet or a dry well at least 10 feet from the home. In areas with heavy rainfall or high water tables, this single addition prevents more problems than any other site prep element. MagicBox’s aluminium frames are non-corrosive, but standing water under any home — regardless of frame material — creates issues over time.

Foundation Options for Every Situation

Foundation choice depends on whether the placement is temporary or permanent, your soil type, local frost depth, and whether you want the option to relocate the unit later. Here are the practical options, from simplest to most involved.

Compacted gravel pad (best for THOWs)

A compacted gravel pad is the standard foundation for a tiny house on wheels and the most cost-effective option for temporary or semi-permanent siting. The construction sequence: excavate 6–8 inches of topsoil across the home’s footprint plus 2 feet on each side, lay geotextile fabric to suppress weed growth and separate soil from aggregate, add 4–6 inches of compacted crushed stone (¾-inch angular gravel, not rounded — angular locks together under compaction), then top with 2 inches of compacted road base for a stable surface.

Total installed cost for a standard THOW footprint (approximately 10 × 30 feet) runs $800–$2,500 depending on excavation depth, soil conditions, and local material costs. This is typically the lowest-cost foundation option and leaves the site restorable if you move the home.

Concrete parking pads

A poured concrete pad provides a very flat, durable surface and is appropriate where the site will be permanent but the home might eventually move. Four-inch reinforced concrete over a compacted gravel base, sloped slightly (1–2%) for drainage. Cost runs $2,500–$6,000 for a typical THOW footprint. The pad remains after the home is removed, which may be an advantage (future parking or shed base) or a disadvantage depending on your plans.

Pier foundations

Concrete piers (either poured or precast blocks placed on compacted gravel) allow the home to sit above grade rather than directly on a pad surface. This improves underfloor ventilation and makes plumbing inspection easier. Piers are placed at each corner of the trailer frame and at intermediate points along the length — typically every 6–8 feet. The home is levelled by adjusting pier height or using shims.

Piers are the preferred foundation for sloped sites where a level pad would require significant cut-and-fill. On sites with significant slope (more than 18 inches across the home’s footprint), piers allow level placement without major earthwork. Cost varies widely depending on slope and pier depth.

Concrete slab (permanent modular homes)

For MagicBox permanent modular placements, a concrete slab on grade is the standard — typically 4–6 inches thick with reinforcement, poured over a compacted gravel base with a vapour barrier. In cold climates, the slab perimeter needs insulation to prevent frost heave and thermal bridging. A slab is a permanent commitment: it determines the home’s exact position and orientation forever. Get the placement right before the concrete is poured, including orientation for solar gain, views, and utility access. Cost typically runs $5,000–$12,000 depending on slab thickness, reinforcement, and local labour rates.

Utility Stub-Outs: Electric, Water, and Sewer

The utilities need to be in position — “stub-outs” ready at the home’s connection points — before delivery. You cannot trench for electrical or water after the home is placed without either moving the home or doing costly tunnelling under the trailer. Plan the utility routes before the site is prepared, not after.

Electrical

MagicBox THOWs use standard RV-style utility hookups — either 30-amp (for smaller models) or 50-amp (for larger models with full HVAC). Your site needs a weatherproof electrical pedestal, positioned within reach of the home’s power inlet — typically within 25 feet. The pedestal connects back to your main panel via a direct circuit. Have a licensed electrician install the pedestal and run the circuit; this work requires a permit in most jurisdictions.

For permanent modular placements, the connection is a hard-wired service entrance — a licensed electrician connects directly to your utility provider’s meter base. This involves scheduling with the utility company, which can add 2–6 weeks to your timeline depending on your area.

If you’re planning an off-grid solar setup, the battery bank and inverter typically go inside the home (MagicBox can integrate these at the factory), but the solar panels mount on the roof or on a ground-mounted array that needs its own pad and conduit run. Confirm the solar system spec with MagicBox during the order process so the factory wiring is compatible.

Water

Run a water supply line from your main supply (municipal or well) to a stub-out position within reach of the home’s inlet — typically the same side as the electrical pedestal. Trench below the frost line for your climate zone (typically 12–48 inches depending on location). PEX pipe is the preferred material: flexible, freeze-resistant, and simple to connect. Install a shutoff valve at the stub-out so you can isolate the home’s supply without interrupting the main line.

If your site is not served by a well or municipal water, a rainwater collection system or delivered-water tank is an alternative — both require planning at the site prep stage. For off-grid water, a 250–500 gallon tank positioned uphill from the home allows gravity-fed supply without a pump.

Sewer and grey water

Sewer is typically the most regulated utility connection. If you’re connecting to a municipal sewer system, you’ll need a licensed plumber and a permit. Trench from your stub-out location to the municipal lateral, maintaining a minimum slope of ¼ inch per foot for gravity drainage. The stub-out should be a 3-inch or 4-inch ABS or PVC pipe capped at the surface, positioned under the home’s drain outlet.

For sites without sewer access, options include: a septic system (requires a percolation test and permit; add 6–12 weeks for design and installation), a holding tank with pump-out service (simpler, no perc test required, but ongoing cost), or a composting toilet (eliminates black water entirely) combined with a greywater garden system or dry well for sink and shower drainage where local regulations permit.

Access Route and Delivery Clearances

The delivery vehicle for a tiny house on wheels is a standard semi-truck or large flatbed — typically 65–75 feet long with the trailer loaded. The access route from the public road to your site needs to accommodate this vehicle. This is the site prep element that buyers most frequently underestimate, and a route that doesn’t work on delivery day is a costly, stressful problem.

Minimum clearance requirements

If you’re uncertain about your access route, video-walk it and send the footage to your MagicBox delivery coordinator before confirming the delivery date. It’s far better to identify access issues 8 weeks out than on the morning of delivery. See our full guide on shipping and delivery logistics for the complete delivery process.

Complete Pre-Delivery Site Checklist

Use this checklist to confirm your site is ready. Everything here needs to be complete before your delivery date — not on the day of, not “nearly done.”

Site and foundation

Utilities

Access and delivery