If you go down to - no, not the woods, today - but the Scottish National Gallery of Modern Art at the end of the week, you will find that Catherine Wheels theatre company has been in wily cahoots with the gallery, devising a promenade installation that chimes in with the current exhibition, Witches And Wicked Bodies.

Inside the self-contained unit known as Modern One, there is now a little house that harbours a very old story. Perhaps you are thinking "exhibition... witches... must be Hansel and Gretel". Actually, Catherine Wheels did a spooky-brilliant outdoors version of that Grimm tale as part of the National Theatre of Scotland's inaugural Home event. In time it came indoors, but this latest venture is no rehash of that earlier triumph. This new work (for everyone aged seven and over) is called HUFF, it is based on the tale of Three Little Pigs and it is the product of two exuberant talents: Shona Reppe and Andy Manley.

They have worked on each other's projects in the past - Manley provided input on Reppe's Potato Needs A Bath and The Curious Scrapbook Of Josephine Bean. Reppe created the superbly detailed sets for his award-winning Mikey And Addie and The Ugly Duckling, which ran at the Arches last December. It is the first time, however, that they have collaborated and for each of them it's a definite shift away from the theatrical forms that have made their shows hot tickets on the global circuit.

For a start, neither of them is performing in HUFF. There are no live actors involved at all. Instead, groups of only three at a time will take off their shoes and go into the specially-constructed little labyrinth of rooms. En route from Mother Pig's home to the exit, what they hear and see and even touch will conjure up the fate of those little porkers as they try to keep safe from the hungry wolf whose catch-phrase, you'll remember, is: "I'll huff and I'll puff and I'll blow your house down."

Needless to say, deciding to make HUFF was the easy part of the process. What followed was a period of aspirational brain-storming that then had to come to heel. Creating different environments that could "speak" in primarily visual imagery - and, in effect, portray characters who were not physically there - had to be anchored in what was practical within the confines of Modern One, as well as tight timescales and budgets. Issues of "how literal? how explicit? how simple? how symbolic?" ping-ponged back and forward as Manley and Reppe tried to work out what each room needed so as to fire young imaginations, and how they could balance out the details so as to avoid information overload.

Some folk would probably have reverted to the safety of what was familiar, with Reppe crafting some plumptious piggy-wiggy puppets to illustrate Manley's storytelling skills. But the urge to do something new in terms of performance work for children was,like that determined wolf, not to be put off by apparently insurmountable obstacles. Moreover, they loved the story - though both remain perplexed as to why so many people think of it as a jolly rhyming tale for nursery tots, or a watered-down cartoon where nobody gets killed, not even the wolf.

"You can discover a lot of fun in it," says Manley "and we've worked that into the objects we use in each room, but it's really meant as a cautionary tale. There's this feeling that the little pigs who try to keep the wolf at bay by building houses from straw and sticks are taking the lazy way out. And it doesn't work. The house built from bricks, however, does withstand the wolf's attacks but..."

Neither is keen to give too much away about the brick room and its contents. What they do say is it raises questions about what we cheerfully assume is a happy ending. Reppe does drop a tantalising hint. "Really - and maybe not everyone will take it this way - it's saying 'yes, you're safe. But at what cost?' If the wolf can't get in..."

She's much more willing to enthuse about how Three Little Pigs is "a gift, visually." "There are so many textures to work with - the straw, the sticks, those bricks - and all kinds of possibilities with colour palettes. As a performer and director, Andy is very visual in his own approach to making theatre. Some people just don't think that way at all. You can suggest something to them, and they really don't understand why you feel it will add anything to an audience's experience. There is a soundscape. Sometimes you have to put on headphones. And you'll always be told when it's time to move on. But we both wanted this to be a highly visual adventure, where the materials used are part of that experience.

"At one point we thought 'sticks? could that be lollipop sticks? could the straw be drinking straws?' But straw bales are amazing to work with. We felt we could push the visual elements in all sorts of ways. Be very playful, or unexpected. But some references had to be true to the original story."

Manley, who is still paint-spattered from a session decorating one of the rooms, admits he's curious to see how the different age groups respond to what's a seemingly unsupervised journey through the installations - there will be CCTV, just to make sure no-one channels their inner wolf and wrecks the place. "I suppose what struck us both about the story is what gets lost in the name of safety. And society, these days, is very risk-averse in how it cares for its children. They seem to spend a lot of time in their rooms. Maybe not rooms built of bricks, but they're still shut off from an outside world that's maybe safer than the virtual world they enter on-screen. The flyer for HUFF asks 'who will save your bacon?' - it's up to everyone to decide that for themselves."

HUFF is at the Scottish National Gallery of Modern Art from Thursday to September 22. Admission is free but online booking is essential at nationalgalleries.org/HUFF