Hardscape: the built structure that carries a landscape and its drainage.

The built, non-living elements of a landscape: paving and paths, kerbs and edging, steps and ramps, retaining walls, seating, pergolas, planters, water-feature structures and surfacing. It is normally executed before planting because it involves excavation, machinery and levels.

Almost always because of what is underneath: inadequately compacted subgrade, poor bedding, no edge restraint, or water trapped below the surface. Surface material is rarely the cause. Getting the base right is unglamorous, invisible in photographs, and the difference between paving that lasts and paving that is relaid.

Paving that lets rainfall infiltrate rather than run off: through porous blocks, open-jointed units or gravel systems on a draining base. It reduces runoff, recharges groundwater and eases stormwater load, which makes it worth using on parking areas, paths and low-traffic surfaces on most Indian sites.

By durability under the expected loading, slip resistance when wet, surface temperature under sun, appearance, local availability and cost, and how easily the surface can be lifted and reinstated when buried services need attention. In hot climates the heat a surface holds is a real comfort consideration, not a detail.

Yes, in nearly all cases. Hardscape involves excavation, compaction, machinery movement and levels, all of which damage finished planting. Buried services should also be laid and tested before surfacing, so that finished paving is not opened again within months.

Only as much as the circulation and use require. Excess paving increases runoff, raises local surface temperature and reduces the planted area doing the environmental work. Where large paved areas are unavoidable, permeable systems and shade planting mitigate part of the effect.