For the duration of the design festival, which took place from 23 to 25 May, the 18th-century palace was transformed into an exhibition space that showcased a mix of workspaces and more homely lounge areas.
It showcased a whole collection of new Hay products, including three lights, four chairs and a handful of home accessories.
The exhibition comes in response to what Hay describes as the "shifting landscape of office environments", where employers are seeking to create more homely offices settings to comfort workers.
It was this that led the brand to Lindencrone Mansion. The building was erected in 1753 and is one of several grandiose mansions built for wealthy citizens in the city's Frederiksstaden district.
"The spaces we have created for 3 Days of Design are about both living and working, and perhaps the divide between those two parts of our existence is not so strict today," explained Rolf Hay, co-founder and creative director of the brand.
"As we look to the future of design, we should consider that a balanced lifestyle sometimes means living where we work, and working where we live."
A large room in the mansion with ornate plaster walls and crystal chandeliers was turned into a lounge area that could be used for informal gatherings amongst colleagues.
One of the new products, the Bernard chair by Shane Schneck, was dotted throughout. It features a wide, solid oak frame with sloping armrests and a pale pink leather seat.
The space was flanked by two long tables that could be used for dining or group meetings.
One was surrounded by the new AAC 100 chair by Hee Welling, which boasts a curved body and high backrest, while the other had the tubular steel Half Time chair designed by Danish architecture firm COBE.
Small study rooms tucked away at the corners of the mansion had desks topped with the newly-designed Matin lamp by Inga Sempé, which has a steel-wire stem and a pleated cotton shade that loosely resembles a coloured parasol.
Another room boasted an office-like installation, similar to Hay's installation for last year's Stockholm Design Week. Amongst the pale blue storage units and work tables were a couple of the brand's new Shade paper bins, which come with a grooved surface and chunky rim.
Other lounge-style areas throughout the building were completed with comfy oversized sofas, where workers could relax, and library-style shelving. The newly released Bubble lamp, originally designed by George Nelson for Herman Miller, was suspended from the ceilings.
"When we started Hay, we didn't produce lighting, so we had to buy lamps for our own stores, and George Nelson's Bubble lamp has been in our shop from the very beginning," added Rolf Hay.
"So this lamp has always been with us in a sense, and now I'm happy to give our Hay customers the opportunity to buy it and have it in their own lives."
The city of Copenhagen plays host to 3 Days of Design every year, with numerous shows and exhibitions that highlight the best of Danish design.
Also at this year's event, Japanese brand Karimoku launched an architect-designed collection of furniture, while Bjarke Ingels and Simon Frommenwiler collaborated to create a bright pink installation that looks like a house.