Guide · Construction basics
How garden hardscape is actually built
Paths, walls and decks all follow the same discipline: put the weight on ground that won’t move, then build in layers. These are the sections we draw from — the same drawings BuildIn AI shows with every construction step.
Schematic, not engineering
Paths & paving
Schematic — typical construction, not to scale. Verify dimensions and requirements with your local building department or a qualified professional.
A paver surface is only as good as what is under it. Excavate, compact the subgrade, add 4–6 inches of compacted gravel, screed about an inch of bedding sand, then set the pavers and sweep joint sand in.
Two details decide whether it still looks right after three winters: the compacted base depth, and the 1–2% slope away from the house. An edge restraint — hidden or visible — keeps the field from spreading.
Gravel paths can skip the sand and pavers; the base discipline stays the same.
Garden walls
Schematic — typical construction, not to scale. Verify dimensions and requirements with your local building department or a qualified professional.
A freestanding wall is a small building: a concrete footing reaching below the frost line carries block or brick courses, capped with a coping that sheds water. Mortar joints are the wall’s weak plane — the footing is what keeps them aligned.
Drainage matters more than most people expect. Weep holes near the base and gravel behind retaining walls keep water from pushing the wall over; a capped wall with no drainage is a wall waiting to lean.
Retaining walls above a low threshold are usually regulated — and taller walls generally need engineered design.
Timber decks
Schematic — typical construction, not to scale. Verify dimensions and requirements with your local building department or a qualified professional.
Schematic — typical construction, not to scale. Verify dimensions and requirements with your local building department or a qualified professional.
Decks carry people, so the load path is explicit: decking → joists at 16 in on center → double beams → posts → footings below the frost line. The connection to the house — the ledger, with flashing and fasteners into the rim board — is the detail most failures trace back to.
If you’re planning a deck, our material calculator prices this exact structure for your dimensions, and the cost guide covers what moves the number.
Common questions
How deep does a footing need to be?
Deep enough to sit below your local frost line — commonly around 36 inches in much of the US, but this varies by region and your building department sets the requirement. Shallow footings in freezing climates heave and crack whatever sits on them.
Do I need a permit for a garden wall or a deck?
It depends on height and jurisdiction: many US jurisdictions require a permit for decks above roughly 30 inches, and retaining walls above a low threshold often count as structures. Check with your local building department before starting.
What goes under pavers?
Three layers: compacted subgrade, a compacted gravel base (typically 4–6 inches for patios and paths), and about an inch of bedding sand. Skipping base depth is the most common reason pavers settle unevenly after a few winters.
These drawings ship with your plan
BuildIn AI turns your backyard photo into a design, then resolves it into components, materials and a construction guide — with the structural diagram on the step where you need it.
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