Grand Designs’ ‘Fossil house’ is for sale in Devon

This unusual Devon property is inspired by an ammonite fossil found on its site and mimics the form of a Fibonacci spiral.

Practice Sadler Brown designed Oat Errish for its current owners, Stephen and Elizabeth Tetlow, in 2017, taking cues for its biomorphic design from the fossil of an ancient aquatic mollusc – a naturally occurring example of the Fibonacci sequence.

‘The inspiration for the shape came from an ammonite fossil that we had on our dining room table,’ the Tetlows told Grand Designs magazine when the organic building appeared on the award-winning show in 2017. ‘The building is shaped in what is known as the golden ratio in both plan and section… It’s found in nature too, such as in the spiral patterns in pinecones and the fronds of a fern. So, the idea was to design our home to reflect the nature around it.’

The five-bedroom Paragraph 55 home is in the Blackdown Hills – an area of outstanding beauty on the border of Somerset and Devon, near Taunton. Its sweeping curved exterior is inset with oak-framed picture windows – each offering a unique perspective on the undulating landscape beyond. The shape of the building also enhances its energy efficiency: it’s fitted with custom curving photovoltaic panels, while the conservatory acts as a solar and heat collector contributing to the building’s MVHR system.

Exterior walls are faced in local stone, while the roof is fabricated from 4,600 slats of redwood cedar, Siberian and English larch that creates a protective shell over the building and helps bed it into its setting.

Inside, living spaces are ‘upside down’: the living room and kitchen are a tremendous sweeping space crowned by arched beams and white walls. Meanwhile, the five bedrooms are tucked beneath, cocooning them as quiet sanctuaries.

Oat Errish is for sale via The Modern House for £1.95m and comes with 7.6 acres of wild meadowland.