New Housing Project Builds on the City's Rooftops

A prototype of a penthouse apartment shows us how the need for more housing in Copenhagen can be reduced by building prefab, environmentally friendly penthouse apartment units on top of existing flat-roof apartment blocks, typically from the 60s and 70s.

From Sunday 28 August, it will be possible in Ørestad near Copenhagen to tour a prototype of a new style of housing that provides healthy and bright housing of high architectural quality at prices most people can afford. The prototype can be viewed at a new exhibition at Rued Langgaardsvej between the University of Copenhagen, Amager and the IT University of Copenhagen.

An 84 m2 apartment unit has been prefabricated in a turnkey industrial process and then hoisted like a ready-made "housing container" into place on top of the flat roof of one of the city's buildings. This type of architecture is particularly widespread at the periphery of the city and could potentially amount to upwards of 100,000 m2 of building ground.

The concept was developed by the SOLTAG network, a consortium of leading Danish companies from the building sector. Utilising the flat roofs as new building foundations relieves the pressure on the city's limited building ground resources.

"It makes sense to think vertically when establishing new housing in the city. Higher up we find fresh air and plenty of daylight – two qualities that are in high demand in the housing sector," concludes SOLTAG, which comprises Kuben Byfornyelse Danmark; the architectural firm of Nielsen & Rubow; the consulting engineering firm of Cenergia; and VELUX A/S. SOLTAG is also backed by a number of innovative building material manufacturers and sponsors.

The penthouse was industrially fabricated by JYTAS A/S. Industrial fabrication is also excellent for precision production of the apartment's technical installations and fixtures as well as for optimising assembly. Prior to fabrication, thorough research and product development were conducted, focusing on design, materials and an architectural idiom that balances daylight and solar radiation.

The design is based on careful placement of vertical windows in combination with roof windows in sloping roofs. The daylight from roof windows can better penetrate deeper into the interior than from vertical windows, while a supplement of sunscreening and Venetian blinds can help regulate the sun's heat. The units are air tight and free of cold bridges, and their energy data meet not only the new energy provisions, which will enter into force at the new year, but also future energy requirements for housing. Furthermore, the units are equipped with a heat recovery ventilation system, a solar heating installation for heating water, solar cells and a small heat pump. All of this enables us to produce quality housing that meets requirements for CO2 neutrality without the need for a traditional heating system and, thus, without the need to couple the unit to the building's existing heating system.

The exhibition on Rued Langgards Vej is also sponsored by the DEMOHOUSE Project under the EU's 6th Framework Programme; the City of Copenhagen's City Ecological Foundation; the Danish Energy Authority; Elkraft-PSO; and Ressourcegruppen Danmark. The Ørestad Development Corporation made the building ground available for the exhibition.

The penthouse apartment was presented to the building sector on 26 August and will be open to the public from 28 August 2005 between 1 and 4 p.m. The penthouse exhibition will run until the end of November and will be open to the public on demand. Appointments for tours may be made via e-mail to For more information, see

Caption: Environmentally friendly, prefabricated penthouse apartments ready to hoist up to the roof of an apartment block. It sounds too good to be true, but it can be a reality in Copenhagen. The exhibition is open to the public from 28 August 2005 between 1 and 4 p.m. The penthouse apartment will be on show until the end of November. Anyone interested may make an appointment for a tour via e-mail to