Have an unused roof terrace? Then your garden-in-the-sky or outdoor living room dreams are going to waste. Because while a bare roof terrace may look like an exposed, sterile expanse of hard surfaces and straight lines, it’s a space ripe with possibilities.

Do you crave an alfresco dining space or more room to entertain? Perhaps you envisage star gazing on warm nights, or gathering around a fire pit with friends? If you lack a garden, it’s a chance to create a little green oasis, and if it’s privacy you seek, your roof may provide the ideal retreat where you can string up a hammock or sink into a lounge chair, far removed from the hustle and bustle below.

A well-considered design can transform an unloved rooftop into an outdoor haven. The following guidelines will help you get the most out of your space.

Technical considerations
Before you jump into choosing your roof terrace decor, there are technical aspects to consider. The weight of planters, pergolas or robust furniture could be more than your rooftop was designed to support, so consult a professional to establish the load bearing capacity of your roof. This will then guide your design, as heavy items may need to be positioned directly above load bearing walls.

If you have a lush roof garden in mind, make sure you have the ability to install an irrigation system and that you have adequate drainage.

Finally, if you plan to use your terrace after dark, check that you will be able to hook up lights.

Shape and structure
Most roof terraces are long and narrow, so use planters or trellises to zone spaces for eating, sitting, or sunbathing. Look at what existing structures can be used to your advantage: is there a corner just begging for a sectional sofa to be fitted into it? Is there a wall you can grow a vine up, or use to attach a shade system to? Can you surround your seating area with planters to make a private garden nook?

Review the view
You roof may well have the best views in the house – but it can also lack privacy from neighbours. Many roofs are also where unsightly air conditioning machinery and solar panels have been hidden from view. If that is the case, think about how your design can block the less attractive aspects and how you can orient your design to capture the best vistas.

Temper extreme weather
The effects of wind increase the higher you go, so a windbreak may be a wise choice. Permeable screens such as louvered or slatted panels are better at filtering wind than solid screens (which cause more turbulence).

Creating shade will also be essential for any daytime use. Pergolas provide both a covered space for dining or lounging, and a support climbing plants. Alternatively, consider retractable awnings or shade sails – providing you have something to attach them to; failing that, a large parasol is easy to take down on windy days.

Beware of assuming that lots of white accessories will make you feel cooler on hot days – all that white can be blinding in sunlight. Instead, go for bold tones or soothing neutrals that will absorb some of the light making it easier on the eye.

Make floor plans
Roof terraces that weren’t originally designed for daily use may be bare cement or an expanse of brilliant white. Investing in a floor treatment ensures the space feels designed rather than an afterthought. Timber or composite decking is a relatively lightweight option that is pleasant underfoot and attractive to look at. If paving is your preference, porcelain is the most durable option: some designers mount pavers on feet, which avoids the need for mortar and also allows for drainage.

Plant perfection
Between the lack of access to groundwater and the exposure to sun and wind, containers will quickly dry out, so choose your plants carefully. Opt primarily for tough, drought-tolerant endemic species that are adapted to the climate. These can be interspersed with succulents, cacti and other plants with thick waxy leaves that retain water well, as well as plants with narrow, pointy leaves (bamboo, rosemary, lemongrass) that have smaller surface areas and thus reduced evaporation.

Accessorise to your style
Is there a particular use or activity you envision for your roof terrace? A barbecue, a telescope or a fire pit, for instance? Plan your zones around these features and choose furniture that is designed for outdoor use.

Finally, stamp your personality on your rooftop with accessories that reflect your style: think outdoor rugs, colourful cushions, lanterns and strings of lights, that will transform it into an inviting and atmospheric space.