Dozens of wooden boxes designed to replicate tree hollows have been installed in the Perth Hills to create habitats for birds and possums in fire-affected areas.

Eighteen months after fire swept through the suburbs of Parkerville and Stoneville, destroying over 50 houses, the bushland reserves are sprouting new growth and native animals are returning home.

Local expert Simon Cherriman was commissioned by the Mundaring Shire Council to build 40 nesting boxes for local reserves as part of the fire recovery program.

He will also teach residents how to build and install them in their backyards.

"The local people had expressed concern for what had happened to wildlife after the bushfires," Mr Cherriman said.

"During a bushfire, most animals will flee the flames and try to get to areas that are unburnt.

"If they are hollow-using animals, which depend on these very old trees which have natural hollows, then they can take quite a while to find a new home."

A badly burned possum emerges from the Stoneville bush earlier this year. ( 720 ABC Perth: Emma Wynne )

The nesting boxes are essentially wooden boxes of varying sizes, placed at different heights in trees for animals to find.

"A whole variety of animals use the boxes, from small invertebrates and insects that you can't even see, to ducks, black cockatoos, parrots, possums," Mr Cherriman explained.

"There are a number of different designs and we try and build them to suit different species.

"Very small tree hollows are used by some of the smaller birds, whereas black cockatoos need a very large tree hole to nest in."

A possum has found a new home in one of Simon Cherriman's nesting boxes. ( Supplied: Simon Cherriman )

Mr Cherriman has been building nesting boxes since he was 10 years old, and is often asked to make boxes for local people who have problems with possums living in the roof.

"We had a possum at home when I was a kid, and my dad was very reluctant to have this thing in our ceiling," he recalled.

"I built this nesting box that I had seen in a magazine, moved the possum out and we wired the roof off, and the possum lived in the box for three years.

"It was a female so it had a baby each year, which was pretty amazing to see.

"That was pretty much the hook I think for me, pretty addictive."

An inviting new home beckons in Stoneville. ( 720 ABC Perth: Emma Wynne )

During the workshops Mr Cherriman ran for the council in June this year, around 40 local residents made their own nesting boxes for their backyards.

"The workshops are a very practical way to engage people in the environmental issues on the area and also learn something that they might not have known," Mr Cherriman said.

"A lot of people in the workshops didn't actually know that a burnt tree can regenerate after a fire."

Also a tree climbing expert, Mr Cherriman plans to return in a few months and look inside each nesting box.

"Later this spring, when the breeding season for birds is more advanced and there is likely to be eggs or chicks in them, I will go out and check which boxes are in use," he said.

"Monitoring is a key part of nest box installation.

"Often these projects are about an initial feel-good response but environmentally, follow-up is really important to see what you are achieving, if anything, so you can use that information in the future."