"I'd been through this phase of writing stuff that felt stale, stuff that I wasn't happy with, and you can kind of tell when your heart's not in something."
She decided to try working in secondment, and ended up in a hotel near Herefordshire where she grew up. All of a sudden the inspiration arrived and songs began to emerge.
"It was honestly like floodgates opening, I just started writing and writing.
"[Being in that location] added a lot to the record because, well, there was something special about it. I couldn't be on my phone, I was staying in a weird hotel where there was no signal, and I was surrounded by the most beautiful countryside, and so there was nothing superficial to distract me in any sense."
Then she joined up with producer Jim Eliot (who's also worked with Ladyhawke and Kylie Minogue) in a converted barn to record the album, and things clicked into place.
"When I worked with Jim I felt like everything I wanted to do I was able to do, and that was just magic."
Writing on her own after a break-up, Goulding found the loneliness confronting but inspiring, so though there are moments of emptiness and sadness to be found on Halcyon, there's also a great deal of happiness.
"I think being alone, and experiencing that loneliness has brought different things out of me, it means that I think more about things. I wrote Joy about someone who has this kind of epiphany or realisation, that moment when you know that everything is going to be okay, it's going to be better."
And it seems things have turned out well for Goulding: she's now in a happy relationship with in-demand DJ Skrillex, and her latest single Anything Could Happen is climbing charts worldwide.
Though Halcyon (which is a reference to a bird of Greek legend that would lay its eggs in a floating nest and make the ocean peaceful and calm) isn't a change of direction for Goulding, she thinks of it as more of a pop record than Lights.
"On Lights it was clear I was heavily influenced by electronic and pop music, but this time I've really committed. I wanted it to be an album about my voice, and about one kind of sonic sound. It's hard to explain but for me it's way more of a pop record, it's more repetitive, it's louder, and it's way bigger."
Indeed, with a voice that can find character in any register, and layers of orchestral sounds along with some folk influences, and strident percussion, it's a definitive and confident album - and one that she hopes will be just as powerful performed live.
"I want to be safe in the knowledge that I can tour and play festivals for a long time. The main thing is that I want a good reputation as a live performer. If I have that, I'd be so happy."
Who: Ellie Goulding
What: Second album Halcyon, out now
Where and when: Performing with her five-piece band on Thursday October 25 and Friday October 26 at the Studio
-TimeOut