Modular building structures with energy-efficient Schüco Alu Inside windows, which contribute to practically zero costs for heating and hot water

Assembly and Completion in the "Field Factory"
Student dormitories that provide high-quality accommodation for as many students as possible on the smallest area - this was the requirement of the builder - Studentenwerk Heidelberg - as part of a pan-European tender. The proposal from the Munich company LiWood AG convinced the client with a modular construction system, which guarantees not only assembly and completion on-site but also an excellent energy profile of the building and rapid construction. After completing the foundation slab, the construction company required only five months to deliver three buildings. An advantage was also the fact that the development, planning, and execution of this "turnkey" construction were handled by a single contractor who perfectly coordinated all operations. The assembly of modules, independent of weather conditions, took place in the "field factory" directly on the construction site. On average, six modules could be produced daily, which were then assembled into the respective buildings floor by floor.

Modern Apartments for 265 Students
The student dormitories comprise three five-story buildings with 265 beds in one- to three-room apartments, including twelve rooms for reading, classrooms, and cleaning supply rooms. The quality of living is enhanced by the buildings' orientation towards the east, south, and west. In particular, the buildings 660 (yellow) and 661 (blue) with an axis running east-west and apartments facing south provide ideal conditions. From the perspective of urban development, all three buildings are homogeneously integrated into the adjacent street Klausenpfad.

Color Concept Expresses Community and Identity
Graduated gray tones of the outer facade, a color concept designed by LiWooD, symbolize the community of the student dormitories. The buildings' identity is shaped by the primary color differentiation - the yellow, blue, and red buildings. This theme is echoed in the internal corridors, lined with irregularly arranged fiber cement panels in three shades of gray. The play with shades in the narrow corridors optically deepens the space.

Energy-Saving Windows with Slot Ventilation
The energy concept of the student dormitories features the ambitious aim of reducing heating and hot water costs to near zero. This was achieved in practice through a combination of an energy-optimal facade envelope, an air-water heat pump, and a powerful photovoltaic system, whose solar yield over a year corresponds to the consumption of all buildings (more details in the energy profile).

Energy losses through the facade were minimized by using patented energy-saving windows from Schüco. The Schüco Alu Inside plastic profile structure achieves insulation levels equivalent to a passive house without the usual steel reinforcements. The industrial, economical production of these innovative window systems is made possible by a patented technology that combines plastic with aluminum. The energy-efficient Alu Inside series is characterized by a significant reduction in weight while maintaining good static properties. Especially for window and door elements intended for passive houses, where highly insulated window elements with steel reinforcement and triple glazing exhibit considerable weights of window sashes, the lightweight constructions of Alu Inside represent a significant benefit.

In the project of the student dormitories, Schüco Alu Inside system windows were used, equipped with triple insulating glazing (Ug = 0.5 W/m²K) and 7-chamber profiles that achieve top thermal insulation values of Uf = 0.74 W/m²K. The windows also exhibit improved sound insulation with a rating of 32 dB.

Ventilation with Closed Windows
In addition to thermal comfort, effective ventilation also contributes to comfortable living. Air exchange in the rooms is ensured by Schüco slot ventilation, integrated into the window frame. Slot ventilation allows for air exchange even with closed windows. Air flows through two small ventilation slots located between the window sash and the frame. Their ventilation flaps have different counterweights, which regulate air passage depending on wind pressure. The supply of fresh air at the top of the window with a volume limiter ensures completely steady air circulation in the room.

Universal Modular Construction
The conceptual approach in designing and constructing the student dormitories in Heidelberg led to the creation of buildings with unrivaled low energy costs. According to the contractor, this efficient modular principle can also be realized in hotel apartments, retirement homes, or spa and therapy facilities.

 
Project Details:

Project Name: Student Dormitories Heidelberg (student one to three-room apartments for 265 students, divided into three buildings)
Builder: Studentenwerk Heidelberg
Development/Design/Construction: LiWooD Heidelberg AG & CoKG, Munich
Project Manager: Dipl.-Ing. (FH) architect Werner Kulessa
Completion: 2013; handover 5 months after completion of the foundation slab
Window System Supplier: Hans Greimel GmbH & Co. KG, Herrsching/Breitbrunn; www.greimel.com
More Information about the Project: www.liwood.com

Energy Profile:

Energy Production: air-water heat pump, photovoltaics
Energy Efficiency: KfW40
Primary Energy Consumption: 20.9 kWh/m²/a
Final Energy Consumption: 16.1 kWh/m²/a
Final Energy Consumption of the Entire Building Complex: approx. 96,600 kWh/a
PV System Output: 120.96 kWp
Yield from PV System: approx. 98,000 kWh/a

Schüco Alu Inside Windows:
Patented and certified window system by Passivhaus Institut Schüco Alu Inside, with a structure that connects plastic and aluminum. The installation was carried out along with the Schüco window slot ventilation.