Design decision
Why this idea works
A low board-formed retaining edge holds a gentle grade at the lounge terrace and gives it a warm textured wall, while native grasses soften the edge with little upkeep. The retaining edge is a real structural element, so its footing and drainage come first.
- The tradeoff
- The layout sets a clear direction, but it also commits the project to fixed relationships. Build the retaining edge with drainage and a footing before finishing.
- How to measure it
- Conceptual range: the lounge terrace field plus the board-formed retaining edge figured separately by length and height.
On your property
Plan it for your site
Keep the concrete field calm so the board-formed edge and grasses read cleanly, and slope the terrace to drain. Build the retaining edge with a footing and back drainage, plan the board forms for the grain, and set native grasses back from the seating.
- Build the board-formed retaining edge with a footing and back drainage.
- Plan the board forms for the grain and set native grasses back from seating.
- Slope the terrace to drain and keep the edge stable against the grade.
Before forms are set
Build implications
- Confirm before estimating A retaining edge with footing and back drainage.
- Confirm before estimating A board-form layout for the grain and grasses set back.
- Confirm before estimating Terrace drainage and a stable edge.
- Measure the site and establish elevations Record boundaries, thresholds, grade changes, utilities, and the dimensions of vehicles, furniture, equipment, or structures that affect the layout.
- Test how the space will be used Check walking routes, turning paths, door swings, working clearances, maintenance access, and the route back to the house or street.
- Resolve drainage, services, and structural support Decide where water goes and coordinate drains, conduit, irrigation, fuel, electrical work, footings, and independent supports before forms are set.
- Define and estimate each concrete element Confirm the slab or footing section, base, joints, edges, and finish, then estimate simple measurable fields separately from steps, walls, drains, and supported features.
Prevent these problems
- Starting with furniture instead of movementDining, cooking, and lounge zones need working clearances and a direct route to the house before the slab outline is fixed.
- Adding services after the pourGas, electric, water, drainage, lighting, and future conduit are easier to coordinate before concrete placement.
- Assuming the slab supports every featureRoofs, pergolas, kitchens, fireplaces, and seat walls often need separate footings or structural details.
Next step
Turn the idea into your estimate
Enter measurements from the property. The conceptual image does not provide a takeoff.
Estimate a similar concrete areaQuestions this idea raises
Why does a retaining edge need back drainage?
Water building up behind a retaining wall adds pressure that can push it out, so drainage relieves that load. It is a standard detail even at low height.
Are native grasses low maintenance?
Established natives suited to the site need little water or mowing, though they take a season to fill in. Match them to your conditions.
- Best when
- Lounge courtyards
- Reconsider when
- Reconsider the idea if circulation, utility coordination, clearances, and independent support for built features cannot be resolved on the property.
- Verify first
- Build the retaining edge with drainage and a footing before finishing.
- Professional input
- Coordinate the concrete contractor with utility and feature installers before the pour
Sources and further reading
- American Concrete InstituteTechnical context for the concrete work beneath outdoor features and furniture zones.
- NRMCA CIP 6: Joints in Concrete Slabs on GradeA practical reference for planning slab panels around fixed outdoor features.
- NRMCA CIP 11: Curing In-Place ConcretePractical guidance on curing methods and timing for new exterior concrete.
