Kindergarten and apartments

The Building

Building post-intervention

The complex is divided into two structures. The residential building is characterized by the building height and the facade design as the main volume of the ensemble. The previous commercial building is deeper and due to its L-shaped geometry, forms an inner courtyard which, with its round arches and the widely projecting roof, has a high spatial quality. The specifications of the city of Chur as client were clear. The artistically valuable ensemble was to be preserved in its original expression. The earlier interventions should be dismantled, the change of use of the annex should be visible from the outside as a renewal but should be connected with the original design. And in addition: "Since Chur has been an energy town since 2011, it was necessary to incorporate the latest findings in energy and building physics into the renovation.”

More Details

The Solution

Solution post-intervention

What is the Solution?

The floors of the ground floor are partially against the ground and partially towards unheated rooms. The decision of the stakeholder was to excavate to receive a very good insulated floor. The thickness is variable, but goes up to 50 cm.

Why Does it work?

The project includes a floor design which is compatible with the architecture expression of the building. The materials are also integrated to maintain architectural relationship with the context.

PROS

Excavating to create a thicker, well-insulated floor provided excellent thermal performance to the building.
A warmer and more comfortable living space was created thanks to this floor insulation.
The variable floor thickness allows the insulation to be tailored to the specific conditions of different parts of the ground floor.

CONS

Excavation can be highly disruptive, requiring significant work in the building, and very costly.
Special care must be taken to avoid undermining the historic building while excavating.
The original flooring and flooring materials were lost.

Insulation material

Foam glass gravel

Insulation thickness

500

Thermal conductivity

0.08

Health issue

information not available

Technical drawings

Installation Method

This retrofit solution is invasive, as it required substantial excavation and modification of the original floor structure. The intervention is irreversible due to the significant changes made to the floor structure.

Moisture Management and Technical Compatibility

information not available

Airtightness

information not available

Before retrofit

After retrofit

Before retrofit

Floor thickness

330

After retrofit

Floor thickness

980

Before retrofit

Floor build-up

Finish concrete [80mm], Concrete slab [250mm]

After retrofit

Floor build-up

Finish - parquet floor [10mm], Underlay concrete [80mm], Impact sound insulation [40mm], Concrete slab [200mm], Insulation - Foam glass gravel [500mm], Lean concrete [150mm]

Before retrofit

U-value

3.5

After retrofit

U-value

0.16