Eek, who is currently working on a number of architectural projects in the Netherlands, said many architects do little more than produce drawings and leave others to work out how to build them.
"I think most architects are in fact not architects, because most buildings are drawings which are filled in by engineers trying to achieve the drawing of the architect," he told Dezeen. "So they are not interested in terms of building."
"I don't mind if I insult architects," he added.
Dezeen met Eek at his Eindhoven workshop – a former Philips ceramics factory in the city's Strijp R district, converted by the designer in 2010. The result attracted requests to collaborate on further architectural projects.
In response the designer set up Piet Hein Eek Architecture in January 2015 in partnership with Iggy Dekkers – an architect who'd lost her job during the recession after being told she "made architecture like a designer".
In addition to renovating an old mill in France's Dordogne region into a pair of holiday homes, Eek's architectural offshoot has redeveloped two disused industrial buildings in Strijp R – in walking distance from the designer's own workshop.
The most recent of these is the RAG building – a former pump house which has been converted into ten apartments. The designer purposefully retained the building's original structure, keeping its distinguishing industrial elements and constructing a central "pathway" with apartments arranged either side.
"The RAG building has a lot of details that are quite different from standard procedures in architecture, but the building is already there so you can't use the standard all of the time, you have to adjust to the building," said Eek.
"I try to highlight the quality. The difference between most architects is that we try to be efficient and pragmatic with what's available, and the other thing is that we like the whole process."
"A lot of the redevelopments are quite nice as long as it's well done with respect for the old building," he added. "As soon as the architects try to do something nice that's the thing we try to get rid of immediately after it's delivered, you know, because they need to do something special."
Eek's partner Dekkers took responsibility for selling the homes herself – in line with the practice's "whole process" philosophy.
All of the RAG apartments were sold before renovation began, meaning prospective buyers made purchases with only orange strings to mark out the proposed floor plans. The studio then worked with the future inhabitants to customise the apartment layouts.
"You build for somebody but they're not involved in the building. It's totally idiotic," commented the designer, who told Dezeen his approach to architecture is more collaborative - allowing both developers and residents the chance to contribute to the concept.
Eek also rejects the idea of renderings, explaining that a previous successful pitch for a project relied on sketches that had been completed in just ten hours.
"We just organically develop a huge building," he said. "As an architect you want to make a building, and we say we don't want to make that building. We want others to do their thing and we take care of the infrastructure and facilitate people's dreams, and that's incredibly nice."
Piet Hein Eek Architecture is currently in the running for what Eek called "the biggest project in Eindhoven at the moment", although details are still under wraps.
Eek isn't the only designer who's made ventures into the world of architecture. Thomas Heatherwick – who claimed designing a building is "exactly the same" as designing a Christmas card – is creating a Maggie's care centre in Yorkshire, England.
Other designers-turned-architects include Karim Rashid, who has designed a seven-storey structure in New York, and Nendo founder Oki Sato, who is working on a shopping centre, station and series of private homes.
Dror Benshetrit, founder of Studio Dror, recently caused heated debate in the Dezeen comments section when he claimed that there was no need to be an architect to be capable of designing buildings.
Eek also believes the movement of designers towards architecture is inevitable, citing architects' lack of technique.
"It's not strange at all and these days it doesn't even make a difference because most architects won't do anything in terms of technique – they have engineers to actually see if it is possible," he told Dezeen.
"We're quite extreme because we actually think about the details of the flooring, the thickness and the concrete and steel, and we try to solve all those details, because we think that it is important that all those are taken care of in a way we like."
He also attributes his architectural success in part to his ability to think "totally freely" about the problem and the solution.
"I don't like standard," he told Dezeen. "If things are standard, I get irritated. If somebody says I make it like this because I always do it, that's a lot of the buildings now. They do it, and every time they do it stupid."
"I would say if it's stupid try and do it again next time better because then you can create a better standard."
Architectural photography is by Thomas Mayer.