Open spaces: internal roads, paving and public realm works built to code.

Traffic loading, subgrade strength, drainage conditions and whole-life cost. Flexible bituminous pavement is quicker and cheaper to lay and easier to patch; rigid concrete pavement costs more initially but performs better under heavy slow-moving loads, in poorly drained locations and where water-logging is a recurring problem. The design is done to the applicable IRC guidance rather than by preference.

Because every layer above it is designed on its strength. A weak or wet subgrade forces thicker pavement layers, and a subgrade that was never tested is the usual explanation for a road that fails in its first monsoon. Testing before design is a small cost against the cost of reconstruction.

For open spaces, parking areas, service roads, footpaths and low-to-moderate traffic areas: particularly where the surface may need to be lifted for services and relaid, and where some infiltration is desirable. They still require a properly designed base, bedding sand and, critically, edge restraint; blocks laid without edge restraint spread and fail regardless of their quality.

By designing levels, camber and cross-fall so that water leaves the surface, and by providing storm-water drains with a defined outfall that actually has capacity to receive the flow. Drainage designed after the road levels are fixed rarely works, and an outfall assumed rather than verified is the most common defect in internal road schemes.

Dust suppression by water sprinkling and covering of stockpiles and haulage, working hour restrictions for noise, silt control so that runoff does not carry sediment into drains and water bodies, and segregation, storage and lawful disposal of construction and demolition waste in accordance with the C&D Waste Management Rules 2016. Where the site sits under a clearance or consent, those conditions apply on top.

Underground services (water, sewer, power and telecom lines that are not where the drawings say they are) and monsoon. Both are managed by early trial pits and service mapping and by sequencing the earthworks and base layers outside the wet season, rather than by adding float at the end of the programme.

They should be, along with kerbs, crossings, ramps and tactile provisions, because a footpath built later to a different level rarely reconciles with the road. Accessible detailing (continuous level, adequate width, gentle gradients at crossings) is set at design stage and is very difficult to retrofit.