In true Kiwi style, the trio - singer Ed Martin, drummer Shelton Woolright and bassist Matthews - were living at a beach bach while commuting to a nearby studio to record the follow-up to their 2011 debut, The Horrifying Truth.
"We'd get up, have breakfast, drive in this little Nissan Micra hire car, I'd get really shitty if I couldn't drive, we'd get there about 9, work till 5, then we'd head back. We had Sundays off," remembers Matthews.
They thought they'd easily finish the album during their eight week stint in Saint-Jean-de-Luz. But something kept getting in their way -- their own perfectionism.
"I'm definitely a perfectionist [and] so's Shelton," says Matthews, the band's chief lyricist.
"We allow each other to be perfectionists [but] we can get a bit long-winded about things."
Matthews says I Am Giant wound up spending most of 2013 working on Science & Survival, "deliberating about certain things".
The result is a super-polished rock record that glistens with radio-ready rock sheen - especially the album's grunty first two singles, Death of You and Razor Wire Reality.
"It's been hard work," Matthews admits. "We paid attention to detail and really got the performances right. If we were listening back to it the next day and it wasn't feeling great, we'd do it again.
"I foolishly said, 'If we don't get it all done, we can do it back at [my London studio]'. It took as much time as it needed to take, I suppose."
I Am Giant fans will discover their second album is heavier than their debut, a result of the constant touring the band undertook as The Horrifying Truth took off around the world.
"I still think it's I Am Giant, but it's heavier," admits Matthews. "I guess we've settled into our sound more. We've pushed things a lot more on this record -- it's heavier but the songs are better."
As for that overly earnest album title, Matthews confirms it's "not a joke".
"I'm sure there's some humour in there somewhere, I just can't remember right now," he says.
It's a line taken from one of his favourite lyrics on the album ("We're just passing by, this collision of science and survival") and Matthews says it reflects the deep thought he puts into crafting I Am Giant's lyrics.
"I'm the predominant lyricist. Usually I'll get a bunch of ideas and I'll show them to Shelton. We'll go through what we want to work on, get the music sorted, and send it to Ed, who'll put down some melodies and iron out things."
As for what his lyrics are about, Matthews wants fans to do some digging.
"There are a lot of different topics throughout the album. I want people to figure it out for themselves. The lyrics take a long time. Sometimes they'll take months. It's hard work - it can be so frustrating."
But that hard work is paying off: I Am Giant have just played to an estimated 30,000 fans at the Orange Warsaw festival in Poland, alongside bands like The Prodigy, Pixies, Queens of the Stone Age, Outkast and Kasabian.
And they're about to embark on a nine-date New Zealand tour that will take them from Invercargill to Auckland throughout July and the beginning of August.
Like those sunny days in France that the band was oblivious to, Matthews isn't concerned about leaving behind London's summer weather for a winter tour in New Zealand.
"Climate wise, Invercargill in winter will be about the same temperature as here," he jokes.
You can take the Kiwi out of New Zealand ...
What: I Am Giant's new album, Science & Survival
Also: Debut album The Horrifying Truth (2011)
On tour: July 17, The Bedford, Christchurch; July 18, Refuel, Dunedin; July 19, Saints and Sinners, Invercargill; July 24, The Royal, Palmerston North; July 25, Bodega, Wellington; July 26, The Mayfair, New Plymouth; July 31, Brewers Bar, Tauranga; August 1, Altitude, Hamilton; August 2, Powerstation, Auckland.
- TimeOut