Modernizations in the Highdeck housing estate: We are creating living spaces with a future

1. Roof work

Construction period:
March 9, 2026 to July 24, 2026

The roof waterproofing is largely leaking and in need of replacement. Connections and parapet flashing are damaged and must be replaced due to the waterproofing work.

PV-ready is not present. Lightning protection is partially in place. Ventilation units are located on the roof.

2. Facade work

Construction period:
March 16, 2026 to November 17, 2026

The facade is fitted with an original insulation system consisting of plastered wood wool and polystyrene insulation boards and exhibits significant plaster damage. The insulating effect of the insulation layers no longer meets modern standards. The insulation is 4 cm thick and has a thermal transmittance of 0.784 W/(m²K).

The ceilings of the underpasses are not insulated and are partly in poor condition (water damage, holes, material peeling).

The building's base is made of blue-painted exposed concrete. This has spalling, in some places exposing the reinforcement. In some areas, the paint has faded or been painted over.

The old insulation is being replaced with an external thermal insulation composite system (ETICS). Optimized connections to windows and balconies further improve thermal insulation. Mineral wool is being used as the insulation material. The new U-value will then be within the range of the GEG (German Building Energy Act) requirement of 0.24 W/(m²K). The facade will be finished in the original color and texture, as agreed upon with the historic preservation office.
The ceilings of the underpasses will be removed and replaced with a new, exterior-suitable suspended gypsum board ceiling. The lighting will be converted to LED and new, vandal-resistant fixtures, matching the original fixtures, will be added. The lighting will be controlled by new occupancy sensors and lux meters.
The concrete base is being renovated in consultation with the heritage authorities. Damaged areas are being repaired, the reinforcement is being protected, and the base is receiving a new coat of paint.
Access to your apartment is not required for the facade work.

Added value (before-and-after comparison)
This improved insulation of the facade and underpasses can save up to 40% on energy costs. This depends on ventilation and heating habits, based on a room temperature of 20°C in living areas and 24°C in the bathroom.
The renovation of the concrete base serves to preserve the building structure and to ensure the building's stability.
Measures that sustainably reduce final energy consumption are considered modernizations according to § 555b paragraph 1 of the German Civil Code (BGB).

3. Heating

Construction period:
Individual date

As part of the tiling work in the bathroom, we will replace your radiator with a towel radiator.
The exact layout can be seen in the attached floor plan.

Added value (before-and-after comparison)
The measure will bring both functional and comfort-related improvements, such as increased comfort (towel drying) and modern design.
This leads to a lasting improvement in general living conditions and, according to § 555b paragraph 5 of the German Civil Code (BGB), is considered a modernization.

4. Electrical system

Construction period:
Individual date

The sub-distribution board, which is still present in most apartments in the cupboard or opposite the bathroom door, no longer meets current safety requirements and must therefore be replaced or upgraded.

The electricity meters in the hallway cabinets are mostly original to the building and technically outdated. The doorbell system dates back to when the building was constructed and is prone to malfunctions. There are no multimedia distribution points. The building is not equipped for solar panel installation.

In the original electrical boxes in the apartments (single-row, flush-mounted), residual current circuit breakers (RCCBs) will be installed for the electrical circuits, and the old circuit breakers will be replaced with new ones appropriately sized for the current load. New, multi-row surface-mounted boxes are already up to current technical standards and will remain untouched.
The electricity meters in the hallways are being replaced with meters featuring modern measuring devices.
The doorbell system is being rewired using bus technology. The apartments will receive new telephones. The doorbell system will be out of service for approximately one week during the upgrade.
Multimedia connections are being pre-installed in the apartments (by laying cables in the shaft with a new socket leading to the living area).

Added value (before-and-after comparison)
The new electricity meters allow for better consumption overviews and lay the foundation for the future use of time-variable tariffs, provided the supplier supports these features. The new sub-distribution boards in the apartments then meet current safety requirements.
Upgrading the doorbell system to bus technology with new apartment telephones makes the system more reliable, easier to maintain, and enables future connectivity to digital systems.
The cable installation for multimedia provides the basis for internet, TV and streaming, with the option of easily upgrading to fiber optics later.
This leads to a lasting improvement in general living conditions and, according to § 555b paragraph 5 of the German Civil Code (BGB), is considered a modernization.

5. Lines/Sanitary facilities

Construction period:
Individual date

The toilet cisterns and hot and cold water meters will be replaced. The ventilation ducts, wastewater and rainwater downpipes will be re-laid. Fire barriers between the floors will also be installed. The riser renovation will be carried out through an opening in the kitchen wall.
For this to happen, the kitchen unit adjacent to the bathroom must be dismantled and cleared, and the area cordoned off. The tenant is responsible for creating sufficient space for construction . Kitchen cabinets must be emptied, the area in front of the shaft cleared (kitchen dismantling is the tenant's responsibility), and the bathroom must also be emptied. A cleared path, 1 meter wide, must be provided to access the kitchen.
During the first week of work in your apartment, it will be necessary to remove the toilet on certain days. During this time, temporary bathroom containers with showers will be available in the courtyard for your use. The courtyard will be cordoned off and accessible only from the stairwells. This will prevent unauthorized access. The bottom of the bathroom doors may need to be shortened to allow for the installation of new tiles and ensure proper ventilation. If the door fits, this shortening will not be necessary.

Added value (before-and-after comparison)
The fire barriers significantly increase fire safety. Additionally, the fresh water pipes are insulated according to the German Building Energy Act (GEG) to reduce heat loss. This makes hot water available more quickly and lowers operating costs.
This leads to an increase in the utility value of the rented property and is considered a modernization according to § 555b paragraph 4 of the German Civil Code (BGB).

6. Sanitary ware

Construction period:
Individual date

The bathrooms are generally equipped with bathtubs, wall-hung toilets with concealed cisterns, ceramic washbasins, and single-lever mixer taps. There are a few floor-standing toilets.

In some cases, the kitchen sink cabinets in the apartments are damaged.

In the bathroom, all fixtures, including bathtubs, sinks, and toilets (including faucets, taps, etc.), will be replaced. Where existing, floor-standing toilets will be replaced with wall-hung toilets; where not yet present, single-lever faucets will be installed. Optionally, the bathtub can be replaced with a shower tray.
The arrangement of the sanitary fixtures remains unchanged.
Defective kitchen sinks are replaced with new ones as part of the pipe renovation.

Added value (before-and-after comparison)
Installing a wall-hung toilet with a concealed cistern makes thorough bathroom cleaning easier and meets today's living and furnishing standards. Furthermore, modern cisterns incorporate sound insulation and water-saving technology.
A new kitchen sink cabinet offers more comfort, better hygiene and a modern look.
This leads to a lasting improvement in general living conditions and, according to § 555b paragraph 5 of the German Civil Code (BGB), is considered a modernization.

7. Drywall and tiles

Construction period:
Individual date

The kitchens have tiled backsplashes, some original to the building and some that have been replaced. The bathroom walls are tiled all the way around up to a height of approximately 2 meters.

In some places, another layer of tiles has already been laid over it, but for the most part, the original tiles from the time of construction are still in place.

8. Hallways and stairwell

Construction period:
June 8, 2026 to November 27, 2026

The recessed lights are fitted with energy-saving LEDs. During the replacement, the fluorescent tubes and ballast are removed or bypassed. The wiring is converted directly to 230 V, and then LED tubes with a suitable base are installed.
In the stairwells, the light sources of the individual ceiling lights are also being replaced by LEDs.
The ceiling cladding is being renewed. The design and colors will remain as they were originally, since the house is a listed building.

Added value (before-and-after comparison)
Installing LEDs reduces operating costs and improves the lighting situation in the hallways, thus saving on operating costs.
This leads to a sustainable increase in the utility value of the rented property and, according to § 555b paragraph 4 of the German Civil Code (BGB), is considered a modernization.

9th elevator

Construction period:
Individual date

As part of this project, the drive system, controls, and cabin doors (using improved and energy-saving technology) will be completely renewed. The elevator cabins will receive new stainless steel interior walls. The shaft doors will be replaced – in consultation with the historic preservation office. Asbestos-containing brake shoes in the mechanical room will be professionally removed and disposed of.
The elevator will be out of service during the work. Tenants will be informed of the exact timeframes in advance.

Added value (before-and-after comparison)
The measure increases operational reliability, reduces downtime, and improves comfort, appearance, and accessibility.
This leads to a lasting improvement in general living conditions and, according to § 555b paragraph 5 of the German Civil Code (BGB), is considered a modernization.

10. Balconies

Construction period:
March 16, 2026 to November 13, 2026

The screed on the balconies is severely damaged in places – with cracks, breaks, and deposits. The existing balcony planters also contain hazardous materials (asbestos) and must be replaced.

The underside of the balcony has been cleaned.

As part of this project, the balcony surfaces will be completely renovated, sealed, and given a non-slip coating. The railings will be refurbished and repainted. The contaminated balcony planters will be professionally removed and replaced with new ones.
The work requires that the balconies be completely cleared – this includes plants, furniture, and any ceiling or wall-mounted fixtures. We will inform you of the exact timeframe in due course.
The ceilings (underside of the balcony) receive a thin layer of insulation which is then plastered over. This reduces heat loss at the transition to the rising structural element.

Added value (before-and-after comparison)
The balconies will be visually enhanced, sealed, and permanently repaired. The new balcony planters will eliminate any potential pollutant contamination.
Measures that sustainably reduce final energy consumption are considered modernizations according to § 555b paragraph 1 of the German Civil Code (BGB).

11. Ventilation

Construction period:
Individual date

As part of the modernization, a new, automatic ventilation system is being installed. The old ventilation ducts are being completely replaced. The new units react to humidity and occupancy, operate quietly, and are energy-efficient. The exhaust air system works in conjunction with the window vents. This ensures that a minimum air exchange is always maintained in the apartment, even when no ventilation is taking place. The ventilation ducts are routed through the building in accordance with fire safety regulations. The ventilation units on the roof are thermally and acoustically insulated and represent the latest technology.

Added value (before-and-after comparison)
These measures improve air quality and protect against moisture and mold. The fans will operate more quietly and reliably.
This leads to a lasting improvement in general living conditions and, according to § 555b paragraph 5 of the German Civil Code (BGB), is considered a modernization.

12. Fire protection measures

Construction period:
Individual date

As part of the modernization, these fire protection barriers are being retrofitted to prevent the spread of fire and smoke through installation shafts in the event of a fire.
As part of the modernization, the distribution boxes in the hallways will be fitted with fire-resistant cabinets that meet current requirements.

Added value (before-and-after comparison)
The measure serves to increase safety and represents a structural improvement in accordance with the current state of the art.
This leads to a sustainable increase in the utility value of the rented property and, according to § 555b paragraph 4 of the German Civil Code (BGB), is considered a modernization.

13. Window work

Construction period:
Individual date

The wooden windows are leaky, allowing moisture and drafts to enter the apartment. These original wooden windows are double-glazed (U-value of existing windows: approx. 3.5 W/m²K) and are often in very poor condition. This significantly reduces living comfort, leads to increased heat loss, and can cause long-term structural damage from moisture. Replacing the windows is therefore necessary to save energy, improve the apartment's value, and prevent damage. (U-value of replacement windows: 1.2 W/m²K)

Some of the apartments already have plastic windows installed. These will not be replaced.

Following the specifications of the heritage preservation office, the existing wooden windows will be replaced with new wooden windows featuring modern thermal insulation glazing. The wall connections to the facade and balcony will be improved as part of this process, to the extent permitted by heritage preservation regulations and the existing structure.
Wallpapering and painting work will take place on the interior window reveals. Window rebate ventilators will be integrated into the new wooden windows to allow controlled airflow, preventing mold and excessive humidity in the apartments. The plastic windows will not be affected.
The window work in your apartment is expected to take 2-3 days. The construction company will notify you of the exact date in due course.

Added value (before-and-after comparison)
Replacing windows improves living comfort and reduces heating costs. The figures apply to most window types and may vary slightly depending on the specific window. Energy savings are expected to be approximately 42%.
Measures that sustainably reduce final energy consumption are considered modernizations according to § 555b paragraph 1 of the German Civil Code (BGB).

14. Cellar

Construction period:
Individual date

Collective lines for various trades run through the tenants' basement storage areas.

The sewage pipes are made of asbestos cement. Some of them are leaking and have reached the end of their service life. Most of the drinking water pipes are uninsulated.

The ceilings are uninsulated.

The wastewater mains are being replaced. There will be brief periods of water shut-off. The drinking water pipes are being insulated.
Furthermore, ceiling insulation will be installed in adjacent rooms beneath heated living spaces.
During the pipe renovations and insulation work, the tenants' basement storage units must be cleared of construction debris. Tenants of the affected basements will be contacted by us in good time and must vacate their basements for the duration of the construction work.

Added value (before-and-after comparison)
The measures taken on the wastewater lines are necessary to ensure the functionality and preservation of the building.
The insulation measures contribute to improved energy savings.
Measures that sustainably reduce final energy consumption are considered modernizations according to § 555b paragraph 1 of the German Civil Code (BGB).