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LichtAktiv Haus

How can energy-efficient architecture and high livability ideally be combined in modernising old houses?
LichtAktiv Haus involves the modernization of a 1950s so-called settler house situated in the Wilhelmsburg district of Hamburg. The experiment shows how the vision of abundant natural light, fresh air and open views can be realised even in the most challenging modernisation project. The aim is to combine optimum energy efficiency and the highest standards of livability in a home that operates on a carbon-neutral basis.

The Active House Radar shows the performance of the building based on calculated and measured data.
Calculation performance     
Measured performance
Energy calculations base on national building





Architectural concept
What makes the conceptual design of LichtAktiv Haus so unique is an innovative modernisation strategy that combines maximum livability with optimum energy efficiency. The once closed structure of the existing building is transformed into spacious rooms flooded with light, providing occupants with the best livability. In the premium version, the two children’s rooms, the two bathrooms and the bedroom are located in the old house. With a so-called ‘daylight lamp’, the space under the roof is extended, creating a central living area and reading room which receives an optimum influx of natural light. The living environment also opens up horizontally thanks to a glass facade extending almost five meters in length and facing the garden. The window area has been increased overall from 18 m2 in the old building to 60 m2. An extension is added, offering space for the living and dining room, kitchen and utility room.
A unique renovation project, LichtAktiv Haus transformed a box-like, closed structure into an open group of spacious rooms flooded with natural light. The LichtAktiv Haus can be realised in different variants - basic modernization and in modules according to financial ability, energetic ambition and need for extra square metres in the extension. 
The present building contains two children’s children's rooms, two bathrooms, a master bedroom, a central living area and a reading room. All rooms feature façade and roof windows that are positioned to ensure optimum distribution of natural light – and the home’s window area was increased from 18 m² to 60 m². Living area has been closed by a five-metres-long glass wall, which could be opened to the home’s garden. Everything is also extended for an open living room connected with a dining room. Also kitchen and utility room has been implemented here. Porch became a link between what is old and new. To provide electricity and hot water solar collectors and photovoltaic solar selles were used – everything to cover energy demands of the house.
The concept of LichtAktiv Haus was based on the "settler spirit", but instead of self-sufficiency in terms of food, the home is self-sufficient in terms of energy. 
Basic modernization
The approach used for this project is a basic way to modernise an existing building without
having to make major changes to the building structure, as only the facade is renovated
to make the building more energy efficient. The building stock is left in its original state, receiving only a new roof with roof windows which offer adequate daylight in the upper floor. Furthermore, solar collectors are being installed on the roof.
The interior of the building is organised more efficiently and provides generous space. The old extension is transformed into a kitchen and living space, creating a new entrance area as well as generous views onto the large garden.
Modular modernisation
The basic structure of the existing building and modular extension are the same as the LichtAktiv Haus, and different in size, materials, and technology. The modular modernisation part consists of an extension. Consisting of a timber frame construction, it allows a flexible modernisation in terms of length and its configuration depending on individual needs. Thus, the occupants are free to design and extend their house as well as to choose the material to go between the timber frames. The main difference to the LichtAktiv Haus is the use of technical equipment and the choice of the materials. The building is efficient in terms of the use of energy and space, and it opens the living area onto the garden.
Product overview 


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The house was designed by: Katharina Fey (TU-Darmstadt ee) and Professor Manfred Hegger; work-planning architects: Ostermann Architekten; engineers: HL-Technik, Peter Andres Lichtplanung, TSB-Ingenieure. VELFAC, WindowMaster and Sonnenkraft supplied the products for the house. Cooperation partners were: Knauf, Eternit, Grohe, Keramag, Nolte Küchen.

Diary of the test family

LichtAktiv Haus booklet

LichtAktiv Haus booklet


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