Gabled homes with circular windows and an unencumbered solid volume hiding cosy yet expansive spaces within—a recurrent presence in several animated cartoons for children and by extension, an oft-drawn motif by young ones during their artistic expeditions—has been affixed by Leipzig-based architecture and interior design studio Atelier ST to design and make A Complex Duplex. The structure, conceived by Atelier ST’s founders and principal architects Silvia Schellenberg-Thaut and Sebastian Thaut, is made up of two large masses. “The shape of the two joined gable roof volumes plays with the semi-detached houses in the surrounding area, not least with a wink,” the architects share. The interiors, however, are seamlessly connected. Gabled structures, which stand as the epitome of residential architecture in Germany, served as the starting point for the architects to conceive this structure that at once ascribes to the contextual style of the neighbourhood and manages to stand out with its unconventional conception.

Atelier ST designs buildings that are subtle yet expressive and that host a series of carefully coordinated spatial experiences. Founded in 2005 by Silvia Schellenberg-Thaut and Sebastian Thaut, the studio works on public and private projects of different scales, in Germany and beyond. “Our focus is on art and cultural buildings as well as special residential buildings. Our speciality is building in a historically evolved context,” the architects share. “We look for places and tasks that challenge us,” they add. The German architecture studio focuses on building projects that blend with the contextual environment. At the same time, these structures embody a vibrant energy and a timeless form and aesthetic. A meld of traditional aspects and contemporary aesthetics, designs by Atelier ST holistically integrate the interiors into the overall concept, as well.

This overarching ethos finds its manifestation within the design of A Complex Duplex, as well. A Complex Duplex lies in close proximity to a forest. A typical suburban area seated on the outskirts of Leipzig, the neighbourhood is adorned with street-facing gable structures and verdant gardens. Additionally, the site is characterised by fruit trees, meadows and mature garden vegetation. The site of the private residence is surrounded by small-scale structures. Hence, the disjointed structure of A Complex Duplex manages to retain this contextual character whilst also fulfilling the requirements laid down by the clients. “Instead of uniform typification, the design pursues the goal of transforming the existing in such a way that an independent architecture is created. A clear and straightforward building volume with special openings into nature. In particular, the views take in the forest to the east and the orchard to the west,” the architects share.

The residential design is configured by Atelier ST for a family of four - a couple and their two children. The couple wanted to move from their converted school building in the city back to their childhood neighbourhood in Leipzig. When asked what the brief shared by the client was, the German architects shared, “They had purchased a plot of land with an old DDR house in their home country, which they now wanted to adapt for their needs. Inspired by their vacations, the clients wanted open, flowing spaces but also a retreat to get away from the stresses of everyday life. They also wanted to incorporate memories of their old home - an old school hall with large arched windows and split levels.”

The specifications described by the clients went on to define A Complex Duplex, which comprises circular and semicircular windows, houses airy residential interior spaces and is seamlessly connected both within the house as well as with the outside environment. “In keeping with the motto two is better than one, Atelier ST placed two narrow gabled houses so tightly together that they merge into one large house on the inside,” reads an excerpt from the project description. The shape of the structure, made up of two joined gable roof volumes, helped the architects conceive a space that fits well within the building lines while also accommodating the demanding spatial programme in a compact and cohesive manner.

The single-shell exposed concrete construction of the peripheral walls is load-bearing and hence, offers support to the overall structure. Acquired locally from the south of Saxony, the concrete used for construction is recycled. Its surface is characterised by a rustic texture that comes from rough-sawn board formwork. This rough texture sits in harmony with the nearby forests and houses.

The thermal insulation of the interiors is made up of hemp limestone, accompanied by clay plaster. Hemp limestone or hempline is an ecological and energy-efficient material not yet widely adopted in Germany. The thermal properties of hemp blocks help achieve a low energy and passive house standard without additional insulation. Its usage, hence, ensures a reduction in heating costs. Hempline also helps with climate control by regulating the moisture level within an interior space. “The monolithic construction method and carbon dioxide storing properties reduce construction costs and the hemp blocks have all the necessary certifications and technical approval in accordance with the applicable European standards,” the architects share. Further, the rapid growth of the hemp plant ensures that the production of the building material is regenerative and sustainable. “Biomass and raw materials for a small single-family home grow on approx. 2-3 hectares in just five months,” the studio reveals.

While the exterior of the residential building appears fairly simple and uncomplicated, its interiors unfold to reveal a sequence of interconnected spaces and levels that confound visitors with their placement and greet one in an almost impromptu manner. Further, the repetitive usage of arched fenestrations as well as arched doors and passageways within the house not only help create a coordinated aesthetic but are also evocative of the barrel vault ceiling in the school auditorium turned residence where the family previously lived. Diffused light filters through the arched windows and openings.

Different zones within the household are placed on different levels. An arched entrance leads to the foyer, which is also connected internally to the garage. This space paves the way for a narrow corridor that is straddled by the staircase and washroom on either side and leads up to the kitchen and dining area on the left and the living area on the right. All these zones exist sans doors and via arched passageways that subtly demarcate different portions within the house. The living area, slightly elevated and double-height, serves as the perfect spot for socialisation, conversations and lounging—all within an unencumbered expanse. An intermediate floor, which sits above the garage, accommodates the master bedroom with its accompanying washroom and wardrobe space. Moving further up the stairs, one is led to the children’s room, guest room and study.

With different zones separated from each other by steps and levels within the house, one can enjoy myriad outdoor views in different directions. Each room offers a novel view of the verdant landscape outdoors. The design of the house is also an attempt at breaking up the oft-practised standards of designing detached house estates. Instead, it melds two volumes that appear detached externally. The play with levels and fenestrations, accompanied by an open plan, creates an openness within the contemporary residence, an aspect that the client particularly insisted upon.

Project Details

Name: A Complex Duplex
Location: Moränenweg 14, 04349 Leipzig, Germany
Typology: Residential (duplex)
Architect: Atelier ST
Project Management Team: Silvia Schellenberg-Thaut & Sebastian Thaut, Juliane Diener
Site Management: Kilpper Architekten
Structural Design: Mayer-Vorfelder und Dinkelacker
Building Services: Winkler HSK GmbH for Heating, Ventilation and Sanitary services; Elektro-Füchse for Electrical services
Area: 560 square meters
Year of Completion: 2023