Keep your pet cool - grow a roof garden for it

Green roofs are good. They clean the air, cool the house below and provide rest stops for birds and butterflies. If you work well with wood and want to try a green roof, why not start by building one for your dog?

Landscape architect Stephanie Rubin and her partner, sculptor Chris Isner, sell doghouses with rooftop gardens for $1,000 (Dh3,673) to $4,000 (Dh14,692).

Your home-made version will cost a lot less — and the dog in residence will appreciate a plant-topped refuge that is cooler, in every sense of the word, than anything else around.

To start, Rubin and Isner suggest you create a general design or scan for ideas on their website, www.sustainablepet.com

The configuration of the walls will vary depending on the size of your pet but the composition of the roof will remain the same: It must be shaped like a sandbox and slope gently, a maximum of 20 degrees.

Build it

At the bottom of the slope, drill holes for two or three bamboo drainage spouts that will pull water away from the doghouse.

The size of the holes should be determined by the diameter of the bamboo, about three-quarters of an inch to one inch.

Cut the bamboo into lengths that will extend about three inches out from the holes you drilled. Be sure seams are well caulked and the wood is well glued with nontoxic, waterproof wood glue.

The designers suggest building with treated wood, which repels fleas and ticks. This also prevents off-gassing. Finish the frame with nontoxic, ecofriendly paint, stain or varnish.

Chosen ones

Using a paintbrush, cover the rooftop with two layers of melted natural beeswax. Or use a rubberised roofing compound that's low in volatile organic compounds or VOCs; one example is Elasto-Seal rubber undercoat primer by Snow Roof Systems.

Next, add the drainage layer: Cover the roof's surface with an inch of gravel or 1-inch-diameter bamboo stalks split lengthwise and placed cut-side down.

Cut a piece of landscape fabric slightly larger than the roof; lay it over the gravel or bamboo. Glue excess fabric to the roof box to keep soil from creeping under.

On top of the fabric, add a 4-inch layer of planting medium — 60 per cent pumice, 10 per cent sand and 30 per cent soil rich in organic material.

Finally, the plants: Rubin's rooftops are filled with pet-friendly, nonpoisonous, mostly native plants that require no pesticides or fertilisers.

The plants are watered just as they would be if they were growing on the ground.