Firefighters were flown from Orkney to tackle a fire so forceful the building it engulfed was ravaged, leaving only a pile of rubble.

But now the world-renowned Fair Isle Bird Observatory (FIBO) is set to rise again after plans were submitted by Glasgow-based architects ICA ahead of projected completion by summer 2021.

The biggest building on Scotland’s most remote inhabited island was destroyed by the fire in March 2019.

Having gathered bird census data since 1948, the observatory monitors trends in climate variations and managers confirmed the vital data had been saved - thanks to digitisation and back ups.

Husband-and-wife team, warden David and administrator Susannah Parnaby, who staff the observatory were unharmed, as were their two daughters, but original artwork and handwritten diaries from pioneering Scottish ornithologist George Waterson were lost.

The Parnabys were able to move into the vacant schoolhouse, while other staff stayed in a flat in the south lighthouse, provided by the National Trust for Scotland, who own the island.

Recording of the data collected continued throughout the 2019 season with the same number of bird watching staff as previous years, although FIBO did lose out on additional data provided by guests.

The new observatory and guesthouse will be situated on the same site as the original, built from timber modules in 2009, making use of the existing foundation footprint as much as possible.

The structure will comprise of pair of gable-ended two-storey structures which will be connected by a single storey building affording unobstructed views over the imposing Sheep Rock on the island’s eastern coast.

The new observatory will be around 10% bigger than the original building with the guesthouse accommodation laid over the first floor surrounding an external courtyard.

FIBO Finance director Mike Ward told The Herald costs were expected to be around £6 million.

Architects at the firm have taken care to draw from existing historical buildings found on the island, nodding to traditional stone dwellings and mimicking traditional styles.

It is expected that planning approval will be granted within 12 weeks by Shetland Islands Council. Construction is scheduled to begin by September this year on the island, which is home to 55 people and lies 24 miles south of Shetland.

The challenges building on such a remote island present are being met head on by lead project architect Steven Byrne, who has designed the timber and stone cladding structure so that much of the materials can be made off site and transported to the island when weather conditions are suitable for the build.

He said: “The prefab panels and timber frames will already have insulation and wall lining in place before being transported to Fair Isle. A kit of parts speeds up construction.”

Weather conditions limit the amount of time builders can spend on the island, while getting to and from, not only the island, but the construction site will present difficulties.

Because of the weather and transport limitations, materials must be robust as contractors cannot attend the site quickly. As much of the construction will be built off site during the winter months, ready for assembly during Spring and Summer 2021.

Mr Byrne said: “It’s an extremely harsh climate where the building is situated and even when we get to the island there’s a challenge in delivery methods. The island itself is almost designing the building and the whole purpose is to view the island.

“It’s challenging but it’s not something we deal with every day.”