Sophisticated hillside living or a house with a glass "head"

Longitudinal structure oriented perpendicularly to the slope with a glass 'head'. Both floors offer an excellent view of the city of Warburg and its surroundings.

It would be hard to find a more beautiful view. The plot has a semicircular layout, and in its center stood a building from 1955. It was a single-story house in the local traditional style with a gable roof and orientation parallel to the slope, featuring an attic and a dominant dormer. The existing structure, the home of the investor's parents, was expanded in 1987 due to the growing family, with an addition in a postmodern style. Locals aptly called the building "the house in the cradle". The view is oriented southeast, with the town of Warburg and its surroundings spreading out below the house, and in the distance, the ruins of Desenberg Castle on a volcanic hill in the otherwise flat area of Warburger Börde.

Competition for a New Project
The owner quickly reconsidered the idea of renovating the old structure. The costs would be the same as for a new building, in addition to limitations in spatial layout and overall design concept. After the final decision to construct anew, the project was entrusted to four local architectural firms. The investor left the architects very free-handed. The requirements were defined only in the following areas: number of occupants, transparency, openness, modern interpretation, and energy efficiency of the building. The winning design was submitted by Ladleif Architekten from the city of Kassel. It turned out that the client was open to a bold and extraordinary concept characterized by the longitudinal, rod-like execution of the building, oriented perpendicularly to the slope. One-third of the length of the structure essentially hovers in the hillside. The main living zones are located in two levels stacked above each other, each oriented toward the front with a view. The ground floor features a kitchen with a prominent glass area, allowing for a view. On the upper floor, the owners have a living area with a terrace and an excellent view of the surroundings.

Part of the brief from Ladleif Architekten describes the outdoor space with sandstone walls and terraces that radiate from the semicircular layout of the plot and integrate original trees and greenery.

Dialogue Between Modern and Regionally Typical Materials
Variations in the facade execution contribute to the differentiation of the building and living zones. The highest floor with an overhang has a ventilated facade made of eternit panels in a shade of red wine from the back. Window profiles and lighting areas are integrated into the envelope made of cement-bonded fiberboards in a horizontal position. Their deeper embedding is important for space dedicated to concealed external shading. The facade on the ground floor, where the main entrance zone and spacious kitchen are located, alternates between transparent and closed surfaces. It opens up toward the valley, where the fully glazed corner across the entire height of the floor allows for views of the landscape, not just while cooking. The entrance gate to the property is also visible from the kitchen and dining room. At the front, under the kitchen and adjacent terrace, the building sits on a plinth made of sandstone from the Weser River, which frames the space around the terraces and creates a background for the underground garages. This element returns the original material to the project, as the historical boundary walls in the slope around the plot are also made of sandstone.

Aluminum profiles in matte gray TIGER with a metallic texture harmonize with the red facade, white ceilings and walls, wooden solid boards, and gray basalt slabs on the floor.

No Barriers Between Internal and External Space
The glazed walls significantly contribute to the quality of life in the house, particularly the opening areas in the kitchen on the ground floor and in the living room on the upper floor. Visually and functionally, the glazed facade and sliding systems break down the barriers between internal and external space. This is especially true when these walls can be opened on nice days, naturally extending the living space to the areas of the terraces and beyond... The described merging and utilization of internal and external space nearly without boundaries led to the choice of a uniform material for the floors: in the ground floor, the architect chose basalt slabs, while on the first floor, hard and durable oak boards were used.
 
Cutting-Edge Technologies
During the planning phase, the choice of facade materials included discussions about steel and copper. However, high-quality aluminum profiles were unequivocally selected for the glazed areas. The aim was to achieve narrow sightlines, automated control, and a uniform minimalist appearance for windows, doors, fixed glazing, and skylights simultaneously. Given the impressive dimensions of the elements, it was necessary to also consider high static load-bearing capacity. The profiles are equipped with highly thermally insulated safety triple glazing, with the weight of individual glass panes being approximately 500 kg. The size and weight of these elements require special technology for assembly with aluminum profiles and appropriate techniques for installation on-site. In connection with highly thermally insulated profiles from the German brand Schüco from the HI (High Insulated) series and maximally insulated profiles from the SI (Super Insulated) series, the elements achieve excellent U values (Ug 0.7 W/m²K; Uw < 1.0 W/m²K).

The kitchen on the ground floor offers a view like from an airplane cockpit. This is made possible by two glazed walls converging in the corner (6.11 x 2.5 m and 7.37 x 2.5 m).

Installation and Finishes
The most technologically sophisticated wall features sliding doors from the Schüco ASS 70.HI system combined with fixed surfaces from the Schüco FW 50+ HI facade system, used in the kitchen and living room. The implementation was provided by Budo Metallbau GmbH from Warburg. The fixed part profiles are perfectly recessed to the floor level, while the movable surfaces are guided on rails embedded in the floor. As a result, there is a completely barrier-free access throughout the space, further supported by an elevator located at the rear of the building. The uniqueness of the Schüco aluminum profiles installed in the facade and roof also lies in their surface treatment. In this case, the investor selected a high-quality textured TIGER surface in gray and matte finish, which harmonizes beautifully with the purity and brilliance of the glass. The color synergy on the facade is complemented by a striking shade of red wine, which contrasts with the white surfaces on the walls and ceilings.

Energy Efficiency and Self-Sufficiency
In addition to design and functionality, emphasis was placed on energy efficiency and sustainability in the proposal. The client requested the use of renewable energy sources while eliminating dependency on a single source. The ideal became a combination of a pellet boiler and a gas condensing boiler. Solar thermal collectors, located on the flat roof, provide hot water year-round. The family house is equipped with a floor heating system and a ventilation system integrated into the facade on both floors. A decentralized ventilation system with heat recovery ensures fresh air supply in the living areas. With such "self-sufficient" measures set in place, the new building achieves very good consumption and energy savings results.

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PROJECT DETAILS: Family House in Warburg, Germany
Architect: Meinrad Ladleif, Ladleif Architekten BDA, Kassel
Construction Company: Budo Metallbau GmbH, Warburg-Dösssel
Execution Period: 2009 - 2011
Usable Area: 280 m2 / 2 floors
Brief Profile: Concrete structure with 16cm (ground floor) and 20cm (upper floor) external insulation and a suspended, back-ventilated facade of eternit panels in red wine shade, triple glazing for windows and doors, fixed glazing, sliding systems, and skylights, external blinds for sun protection
Systems: Schüco FW 50+.SI (for fixed glazing and skylights), Schüco AWS 75.SI (window system), Schüco ADS 75.SI (door system), Schüco ASS 70.HI (sliding lift doors, motorized drive hidden in the frame)
Energy Concept: Pellet boiler combined with gas condensing boiler (backup source), solar thermal collectors for hot water, floor heating system throughout the house, integrated ventilation system in the facade - decentralized ventilation system with heat recovery in the living areas of the house, approximate consumption values: useful energy around 56 kWh/m²a, total energy around 66 kWh/m²a, primary energy around 18 kWh/m²a.