"hellohelio+", plus-energy-homes in green neighborhoods

energy-generating housing group of single family garden houses in cooperative direct-development model


The construction of Europe's first affordable plus-energy-neighborhood with 25 single family houses and 6 duplex apartments organized around a common square will start in May 2011 in Offenbach, Germany. The minimum-energy-houses are equipped with photovoltaic panels that provide energy for heating, hot water and the household electricity, possibly including energy for mobility with e-smarts and e-scooters. The goal of providing these qualities at very affordable costs is possible as the result of three key factors: (1)The design of the houses and the technological equipment are at the same time (architecturally and technologically) sophisticated and minimalistic, (2) the photovoltaic panels on the roofs are installed and owned by the city's energy supplier and (3) the development is based on the model of "Baugruppen" (a direct development model where private clients with assistance of the architect contract directly with the individual trades and thus save overhead costs).

Although not only the insulation standard but also the technology used is meanwhile each for itself off-the-shelf standard, it's affordability and it's successful market placement has been possible through the unique combination of a win-win contracting model:  The special development model in cooperative client groups and of an architectural and unbanistic standard unknown in the industry. bb22/wohnbund in collarboration with leber architects has specialised in this approach to project management and architecture through a series of award-winning realisations in the Frankfurt region, i.e. Cooperative Housing "Frankfurt Families", Group Development "Courtyard Houses Riedberg" and "Green Houses Riedberg", 3 Housing Groups in Darmstadt, just to menton a few.

With a 2 storey modular house of 6,3 x 10,1 Meters as a base, the architects developed a series of house types that can be pre-configured by the clients in an internet configurator (available from November 2009). this configurator generates for each variation plans, costs and other raconsequences, enabling the client to adjust precisely to individual wishes and posibilities. The houses are entirely prefabricated and controlled in the workshop, then delivered to the site and built up within 6 weeks.

All variations keep on the exterior a unified character of the entire neighborhood, clients' wishes are only marginally possible here. Even garden shacks and fences come within the system and are mandatory for the client. This provides for a form of sustainability of the developement that is often neglected: Even on the long term the good neighborhood and the unified character cannot be destroyed by the untrained taste of the regular client and by the bargain offers of the home-builder construction supermarkets. But what on the first glimpse seems to be constrainig for the client, quickly turns out to be asset: the home-builders understand the high quality of the elements, are happy that shading and roofing, protection and storage are all there and well designed. The industry simply does not normally provide any ideas and designs for these supposedly "unnecessary" decoration.

All variations of the houses provide base standards:

- Open and very straight foward designed floor plans that provide generous spaces (room height of more than 270 cm in the ground floor) with at the same time high efficieny in sizes. Exteriors are well arranged and protected, exterior storage is standard. The floor plans can "grow" and "shrink" with additions and moveable separations, providing a home for changes of life styles and family sizes.

- Very large windows to the south and the west for energy gains and with full sun-shading with sliding shutters. The windows are wood windows with core insulation in form of "air bubbles" (Airotherm), with triple "white" glass panes with high solar gains factors (61%) and "warm edge technology".

- The exterior walls are thermal-bridge free 3-layer wood constructions, insulated with recycled cellulose, one of the only insulation material that provides protection against long-wave radiation losses and that is both in production and in recycling fully sustainable. The exterior cladding is an undestructible artificial stone panel in friendly colors or a 3-layer wood panel.

- The houses are equipped with regenerative air systems with heat regains and earth collectors (for winter pre-warming and summe cooling of the air intake). The warm water is provided directly at the faucets without losses through circulation and storage. The heating is an immediately responding floor heating system.

- Massive hardwood floors, interior doors with full room height, designer bathroom equipment and French window doors in the bedrooms are standard.




project development, concept, design, realization, urban design


in planning


wohngeno green developments

scope 1,1 hectares




stefanie schuster (project architect)


maheras, wilhelm

project partners   

wohnbund frankfurt gmbh, leber architekten, darmstadt


mainfeld, frankfurt

graphic design

axel schneider / gojo