Design requirements and design concept: The project is an attempt to create high-quality architecture and a modern home with unconventional methods. The focus here was the cost-efficient building activity and scrutinizing supposedly legal standards. A significant part of the solution was to transfer material from the industrial construction into housing construction in an appealing way.
World Architecture & Design Awards 2019
Third Award Award | Category: House Design
Architects: Jürgen Lehmeier
Studio: büro für bauform
Team: Jürgen Lehmeier, Eduard Klotz, Kathrin Krones
Building location Pirna/ Sachsen
Property 1107 m2
Living space 118 m2
Construction costs 292.000.-€
Design requirements and design concept: The restricted budget of 300.000,- EUR for the manufacturing costs for the cost type 300+400 collided strongly with the space requirements of the client. The optimal exploitation of the development plan and the building law led to disassembling the building into its necessary parts, optimizing it and reassembling it additively. The compulsory eaves height of the building with 5,5m and the maximum permissible eaves height for the garage with 3,0m were decisive. The central block, here defined as the conservatory, is not subject to any requirements and serves as a mediator for the other two parts of the building, contains the development [of energy] and collects and distributes energy.
The residence: The building structure meets all legal requirements of the development plan and the building regulations. It is also the section of the building with the least length. It includes all functions of a home. 3 bedrooms, kitchen and dining room.
The garage: With the eaves high of 3m the garage also meets the required maximum height of the state building regulations. It also provides all additional functions of the building like the technical rooms, as well as a toilet and an entrance.
The energy garden, the energy concept: The middle building combines several functions at once. It serves as the central element for the distribution and development [of energy], it mediates between its neighbors and is part of the energy and ventilation concept. Because of the big air volume in the middle building, a ventilation system is not necessary. The energy garden acts as a large air/heat collector and distributes the energy in the house through natural convection. Sensor controls open and close the large north-facing skylights and dissipate too much heat if applicable. The middle building consists of the material polycarbonate which is mainly used in the industrial construction. The building material as “Mehrkammerplatte” with a thickness of 60mm combined with thermally separated profiles reaches a whole U-value more than a triple glazing. The profit from solar energy compensates the larger losses in the critical months of December through February. On sunny days in the winter heating will not be necessary during the day. A base plate with a higher thickness and parts of solid construction ensure an adequate storage mass in the house to balance temperature peaks. Efficient low-temperature systems for heating were installed throughout the house.
Construction/material and budget: A surfaced-coated concrete floor slab is used for the ground floor, into which all the media including the underfloor heating have already been integrated during the early construction phase. This process is borrowed from industrial construction, but for housing construction without a known example so far and required rethinking on the part of designing as well as implementation. That is why the trades of electrical and sanitary have already been at the construction site from an early point on. The facade made of polycarbonate together with the timber skeleton construction represents an extremely cost-effective design. The material has a light- transmittance of approx. 60% under excellent thermal insulation properties (up-value 0,71 W/qmK). The result of this is light-flooded interiors.
The mounted ventilated facade of the remaining building consists of standardized trapezoidal sheet metal and is as a construct the most sustainable form of the facade. All materials remain separable and recyclable. Wood/aluminum windows resume the materiality of the skeleton construction and contrast conscious with the cool concrete. They provide a pleasant and warm ambience in the interior.
Next to the waiver of a cellar and the consistent exploitation of the building law, the transfer of existing standards from the industrial construction especially led to success. The main focus was to develop details and to combine different materials, so that the claims of a residential use are actually taken into account. This is where a lot of rethinking had to be done and a lot of persuasion on all sides needed to be achieved. The result is a confident building, which seeks for discussion, but does not break the tradition with its form and appearance as a prototype of a house.