Terracing splits one height difference across two or more shorter walls. It often avoids the engineering and reinforcement a single tall wall would require, it usually looks better on a residential lot, and it creates several usable levels instead of one. The catch is that tiers set too close together stop behaving as separate walls.
Height limits that push you toward terracing
Segmental wall systems have published limits for unreinforced height, above which geogrid reinforcement or engineered design is required. Local rules also commonly set a height at which a permit and stamped plans are needed.
Terracing keeps each individual wall below those thresholds, which can simplify a project considerably. It is not a loophole, though — a tiered arrangement built too tightly is treated as one taller wall for design purposes, because that is structurally what it is.
The other driver is appearance. A single tall wall in a residential backyard reads as infrastructure. Two shorter walls with planting between them read as a garden.
Spacing between tiers, and why it matters structurally
The upper wall sits on the soil that the lower wall is holding. If it sits close to the lower wall, its weight and the pressure behind it are transferred into the lower wall's backfill zone — effectively loading the lower wall as though the two were one.
Design practice is to set the upper tier back from the lower one by a distance related to the lower wall's height. Set back far enough, the tiers act independently. Set back too little, the lower wall is carrying a load it was not sized for, and it is usually the lower wall that fails.
This is the detail most often ignored on DIY and low-bid tiered walls, precisely because a generous setback consumes the flat space the terracing was meant to create.
Drainage across multiple tiers
Each tier needs its own drainage zone, pipe and outlet. Water shed by the upper terrace arrives in the lower tier's backfill, so the lower wall typically handles more water than the upper one.
The tiers also need surface drainage between them. A flat planted strip between walls collects water unless it is graded to fall along the terrace toward a controlled discharge point, and standing water on a terrace ends up in the wall below it.
Getting this right at design stage is straightforward. Retrofitting it means excavating a finished terrace.
Planting the terraces so they don't become maintenance
The strip between tiers is often too narrow to mow and too visible to neglect, which is why planting choice matters more here than in an open bed.
Choose things that spread and stay put: low evergreen shrubs, ornamental grasses, creeping junipers, liriope, and groundcovers that knit together and suppress weeds. Avoid anything that needs regular pruning at height, and avoid trees entirely — roots and retaining walls are a slow-motion conflict.
Mulch on a terrace washes off during storms unless the surface is level and the planting is dense enough to hold it. Dense planting is the better long-term answer than more mulch each spring.
When one wall is still the right answer
Terracing consumes horizontal space. Where the slope is short and steep, or the yard is narrow, setting the tiers back far enough leaves you with two strips instead of one usable area — at which point a single engineered wall gives you more of what you wanted.
It also costs more in some cases: two walls means two bases, two drainage systems and two sets of caps, which can exceed the cost of one taller reinforced wall.
Southern Style Turf & Design designs terraced and single-wall solutions across Lake Norman and will show you both where the site allows a genuine choice. Free on-site estimate.
Frequently asked questions
When should you terrace a retaining wall instead of building one tall wall?
When the slope is long enough to give up horizontal space, when keeping each wall shorter avoids reinforcement or permit thresholds, and when you want multiple usable levels rather than one.
How far apart should terraced walls be?
Far enough that the upper wall's load is not transferred into the lower wall's backfill — a setback related to the lower wall's height. Tiers built too close behave structurally as one taller wall.
Does each terrace need its own drainage?
Yes, each tier needs its own aggregate zone, pipe and outlet, plus surface grading along the terrace so water does not stand on it and feed the wall below.
What should I plant between terraced walls?
Low evergreen shrubs, ornamental grasses, junipers and dense groundcovers that hold the surface and suppress weeds. No trees — roots and walls do not coexist well.
Want this looked at on your property?
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