When Kiran Sarin built her dream house in Delhi's New Friends Colony there was only one thing wrong: there wasn't enough space for the elaborate garden she had always wanted.

But nature enthusiast Sarin didn't let that stop her. "I had a garden made on my terrace. It's good to bring nature into the house," she says.

Today, her rooftop garden is in full bloom. It's about 20 ft from the ground but has a lawn in the centre surrounded by an astonishing collection of seasonal and perennial plants. The garden attracts scores of birds and also a few squirrels.

Sarin has found an answer to a dilemma that many city dwellers face. Only a privileged few in cities like Delhi can have real gardens. But, as Sarin has shown, there is an alternative. You can have a full-fledged garden made on your terrace. Be warned, however, that it is a messy and lengthy process.

The first and extremely important step is to have your terrace water-proofed. Otherwise there's a risk of leaks. Also, the terrace must be strengthened so that it can take the weight of all that earth and grass.

This type of work needs a contractor or a civil engineer. Says Rajeev Singh of Sansar Greentech, a leading landscape firm, "If the building is new then one can go for proper water proofing with slopes and can accordingly give the look of a natural garden. However, for old terraces one needs to form a base above the ground level with iron frames. This is further strengthened with fibre sheets."

The process takes between one month and two months and can cost anywhere upwards of Rs 20,000 depending on the size of the terrace.

The next step is to get in touch with a nursery or a landscape artist. Says Vikram Saini, of Masjid Nursery, "Once the civil engineering work has been done, we set up the garden."

Saini's job involves spreading a thick plastic sheet across the terrace. On top of that he lays river stones and then puts a net. This prevents the earth from draining and eroding.

Once the basic foundation has been laid, a mixture of earth and manure is spread out equally and then the grass is sown. The earth is generally between six inches to nine inches deep and therefore the roof needs to be pretty strong, otherwise it might give in after a few years.

This process takes between a week to 10 days and costs between Rs 40 to Rs 70 per square foot. Says Saini, "The costs are higher for a smaller terrace since the labour and transport charges are the same and it is not conducive for us."

Once the grass is ready, flower beds can be made and all sorts of plants can be grown. The only thing you can't do -- obviously -- is plant trees.

Singh recommends plants with short roots and of an evergreen nature as compared to big plants or those which require a lot of water. If you wants big plants then you should plant them in pots.

But looking after a terrace garden can be a bit different from looking after a garden on terra firma. Says Sarin, "Extra care needs to be taken during summer months as there is no natural shade in the form of trees and so an artificial shade needs to be created."

There are other important points that mustn't be forgotten. When getting a terrace garden made, remember to get a water connection up on the roof, or you'll forced to carry buckets to the terrace to water the garden.

Also, it's better if the staircase leading to the terrace is outside the house. That's because all the plants, earth and manure need to be carried to the top and the house could get extremely messy otherwise.

What's the best time to get a terrace garden made? Says Saini, "Between February and March is a good period. Then, by the time the monsoons come, the earth has settled down and the garden is in place."

How big a terrace do you need to have a full-fledged garden? Most nursery owners feel that the terrace should be at least 1,500 sq ft for the garden to really blossom.

"If the terrace is large we can do a lot of things such as laying down a path or making a rockery," says the manager of a leading nursery in Delhi.

Does this mean those of us with small terraces should give up the idea of having plants in the house?

Says Saini, "If your terrace is not very large or if you stay in a flat and have a balcony, you can always keep potted plants. You may miss the grass but there are loads of plants that bloom in pots."