A terrace planned for evenings, monsoons and the weight it carries.

Outdoor rooms, planned like indoor ones.

We begin with how you would like to spend time up there: quiet mornings with plants, dinners for eight, children playing, a barbecue on weekends, or all of these. Each use needs a different amount of level floor, shade, power and water, and the mix decides how the terrace is zoned. A terrace that tries to be everything everywhere ends up with furniture in the way of the garden.

The roof slab sets the limits. Soil is heavy when wet, a lawn build-up heavier still, and a raised deck or pergola concentrates load at its supports. We work with what the structure was designed for, use lightweight growing media and raised beds where full planting is not possible, and keep the parapet, the drainage outlets and the waterproofing layer intact. Fixings that pierce the slab are the commonest cause of leaks into the rooms below.

Water is the second constraint. Bangalore's monsoon puts a lot of rain on a flat roof in a short time. Decks sit on pedestals so water runs beneath to the existing outlets; planters stand on trays or drained bases; furniture and cushions have somewhere dry to go. Planned this way, the terrace drains as well after the work as it did before.

Shade and light shape when the terrace gets used. A pergola with slats or climbers, a retractable awning or a mature potted tree can make a west-facing terrace comfortable by late afternoon. In the evening, low bollards along paths, warm light under seating and a few uplights on planting do more than one bright flood. Weatherproof sockets for a fan, a speaker or a barbecue are easy to add now and awkward later.