Above the village of Ullapool on the West Coast of Scotland sits a house with enough green points to stir even the hardest of eco-warrior hearts. Every piece of timber has been checked for chemicals, every splash of varnish and paint is organic and each hand-chiselled slate on the roof is local and reclaimed. It also looks stunning.

Danielle Grunberg originally had no intention of building an eco-bunker to satisfy her environmental principles. As soon as she saw the site she knew that whatever was built, the beauty of the Highlands had to be reflected inside and out.

But what she hadn't anticipated was the exhausting, time-consuming and often frustrating hunt for the greenest methods of construction. "I would spend hours ringing laboratory after laboratory checking on the wood. I refused to have anything pressure treated because it has all sorts of chemicals in it ... Some of the claims made are outrageous and the only...