Add a room logo
About us

About us

In 2006 my husband and I were running a business rebuilding and redecorating old Swedish summer houses. We soon realised that there was a need for a new type of house – a small, high quality, well built house made out of sustainable materials where every square meter was well thought through and the living space could be increased by merging the outdoors and indoors in different ways.

It was then that we decided to develop a small house with many possibilities, a house that can grow according to different needs. Our aim is not only to build a small house but to create a small home which can be enjoyed for many years to come without the need of spending excessive time in the renovation or rebuilding process.

To accomplish our idea we approached one of Denmark’s most well-known architects Lars Frank Nielsen and with his help our modular house was born.

Our modular housing system allows the owner to add or subtract modules and combine them in different ways with endless possibilities.

It’s truly wonderful and exciting to see how our customers combine and use the wealth of modules and elements to create their perfect home.


Lars Frank Nilsen

Lars Frank Nilsen

Lars Frank Nielsen is one of the founders of Danish architectural practise 3xN, well known for numerous high profile buildings in Denmark and abroad. He qualified as an architect in Denmark and after many years at the helm of 3xN he decided to focus on the design of small buildings by setting up ONEN. ONENs aim is to develop products that provide simple solutions to complex problems. Their focus is on functional, minimalistic and sustainable design.

Add a Room developed the ONE+ system in collaboration with Lars Frank Nielsen.

Lars Frank Nielsen explains:

“The project started as a refinement of the mini house concept in Sweden. We, Add a Room and I, wanted to provide a design alter­native to the existing mini houses in Sweden called Friggebod that mostly look like play houses for children. Our goal was to design a simple, almost minimalistic house, a house that can stand alone, but also a house that can be pieced together unit by unit. During the design process, there has been an evolu­tion towards a true “multi-unit-concept”: you can start with a single unit and enlarge it step by step into a genuine holiday home.”