Kohlerhaus

The Building

Building pre-intervention

Building pre-intervention: 23_historic_image_1.png

Building pre-intervention: 24_historic_image_1.png

Building post-intervention

The building is a big residential house, part of the building is dated 14th century. The use of the building changed a lot of times. With the last renovation ten flats were designed: one is permanently occupied; the others are holiday apartments. The historical research carried out by the architect revealed the rich past of the building, that served as priest house, hotel or guest house. The retrofit of the building included external insulation the wall with reed mats, new replica windows and new building services (radiating heating and mechanical ventilation).

More Details

The Solution

Solution post-intervention

Solution post-intervention: FotoBaustelle_3.png

What is the Solution?

A massive stone wall was renovated with a combination of external and internal insulation using reed mats and insulating plaster. On the outside, 12 cm of reed mats and 3 cm of insulating plaster were used and internally 2 cm of reed mat and clay plaster were applied. Only in the ground floor wall heating system is installed. This due to two reasons: the absence of niches in the ground floor (present instead in the upper floors) makes it difficult to position the radiators; the wall heating system helps in case of rising damp.

Why Does it work?

A natural material for the insulation of the wall was chosen to respect the existing stone wall. Moreover, the architect tried to reconstruct the external aspect of the wall as it was in 1784: the window framing and the type of plaster are part of this choice. The coupled use of external and internal insulation makes the solution moisture safe. The wall heating system in the ground floor intends to stop the rising damp.

PROS

Use of natural material.
The low risk of interstitial condensation because the wall is warmer thanks to the external insulation.

CONS

The solution cannot be used if the external wall is decorated and changes the volume of the building.
The depth of the opening’s changes.
The material is prone to decay in case of water infiltration.

Insulation material

Reed mat

Insulation thickness

140

Thermal conductivity

0.065

Health issue

information not available

Technical drawings

Additional documentation

Kohlerhaus - reed mat.pdf

Installation Method

On the outside 12 cm of reed insulation and on the inside 2 cm with clay plaster were installed. Only in the ground floor wall heating system is installed. This due to two reasons: the absence of niches in the ground floor (present instead in the upper floors) makes it difficult to position the radiators; the wall heating system helps in case of rising damp.

Moisture Management and Technical Compatibility

The coupled use of external and internal insulation makes the solution moisture safe. The wall heating system in the ground floor intends to stop the rising damp.The temperature, relative humidity and the CO2 level are monitored in the bedroom and in the living room in two flats; outside temperature and relative humidity are also monitored. Interstitial temperature and relative humidity are monitored between the external insulation and the stone wall, within the stone wall, between the internal insulation and the stone wall, and the internal and external surface temperature.

Airtightness

Attention was paid to the joints walls-roof and walls- windows