The single-storey bungalow, built in 1970, was largely in its original condition. Particularly notable were the existing windows, which still carried a date stamp from November 1969. As a result, their thermal performance was entirely inadequate by today’s standards – the double-glazed units provided very limited insulation and led to significant heat loss.
As part of the partial renovation, the window replacement was used as an opportunity to significantly improve living quality. Instead of simply replacing the existing windows, modern triple-glazed patio doors were installed. This solution not only provides substantially better thermal insulation but also creates direct access to the garden from all bedrooms.
This refurbishment of the existing building demonstrates how well-considered planning can achieve multiple improvements at once: more natural light, a stronger connection to the outdoor space, and a sustainable increase in energy efficiency.
Due to the new door openings, the existing radiators had to be repositioned. The radiators were moved to the side, which required adjustments to the heating pipework. Sections of the subfloor were opened to reroute the heating pipes to their new locations.
This measure illustrates how an energy renovation often requires technical adaptations, while at the same time offering an opportunity to optimise existing systems for greater long-term efficiency.
During the construction works, the interior finishes were also upgraded. The existing laminate flooring was replaced with high-quality parquet. In addition to its improved appearance, parquet offers greater durability and contributes to a healthier indoor climate – an important aspect of sustainable refurbishment of existing buildings.
A key element of the energy renovation was the improvement of the roof insulation. The existing 6 cm glass wool insulation was removed and replaced with a 22 cm layer of sheep’s wool insulation – an ecological and highly effective solution.
To access the roof space, the gypsum ceiling in the smallest room was removed. This proved to be a sensible decision, as the other rooms retained well-preserved timber ceilings typical of the building’s original 1970s character.
After removal, the roof space was thoroughly cleaned, and a vapour barrier was installed and carefully sealed – particularly around all rafters and structural elements. This precise workmanship is essential to prevent moisture entering the insulation layer and to ensure long-term performance.
As part of the renovation strategy, it was deliberately decided not to add insulation to the external walls. Although full façade insulation is often considered the optimal solution, experience in existing buildings shows that this is not always practical or cost-effective.
In older buildings, additional façade insulation can create complex thermal bridges, which are often difficult and expensive to resolve. Critical junctions such as foundations, roof edges, and window reveals require highly detailed planning and execution.
For this reason, the renovation focused on the areas with the greatest heat loss – windows, doors, and the roof. This approach enables a highly effective improvement in energy performance while maintaining a proportionate level of intervention, making it a typical example of a sensible refurbishment of an existing building.
The outdoor area was also upgraded as part of the renovation. The roof overhang above the seating area was additionally insulated to prevent heat build-up in summer. This measure has proven effective, keeping the seating area pleasantly cool despite its southern orientation.
In addition, a pergola was constructed in front of the south-facing bedrooms and planted with grapevines. Since the existing roof overhang did not fully cover the area, it was extended with a carefully designed glass roof. The pergola and glass roof were deliberately coordinated in both material and colour, creating a harmonious architectural composition.
This partial renovation of a 1970s bungalow demonstrates how targeted refurbishment of an existing building can significantly improve both energy efficiency and living quality.
A refurbishment that preserves the character of the house while enhancing living comfort and clearly demonstrates the potential of existing buildings – carefully planned, precisely executed, and in every respect a complete success.
| Area of expertise | Addition / Alteration / Renovation / Architecture |
| Status | implemented |
| Year | 2021 |