NEWSLETTERS
In Türkiye, various technical regulations have been introduced to reduce heat loss in buildings, improve energy efficiency, and support sustainable construction. Within this framework, TS 825: Thermal Insulation Requirements for Buildings and the nSEB (Nearly Zero-Energy Buildings) approach play a particularly important role.
Although TS 825 and nSEB are both key tools in achieving sustainable construction goals, they are often confused with one another. While they share similar objectives, they differ significantly in terms of scope and application.
What Is the TS 825 Standard?
TS 825 is a national standard that defines the rules and calculation methods related to thermal insulation in buildings. Developed to reduce heating and cooling energy consumption and improve energy efficiency in buildings across Türkiye, the standard specifies thermal transmittance coefficients (U-values) for building components as well as minimum insulation requirements.
First introduced on 14 June 2000, the standard was updated in 2024 to include revised minimum thermal insulation requirements for different climate zones and calculation methods designed to limit heat loss while taking both heating and cooling energy demand into account.
Unlike previous versions, the updated TS 825 standard evaluates not only heating energy demand but also cooling requirements, providing a more comprehensive approach to building energy performance. In addition, the number of climate zones in Türkiye was increased from four to six.
In summary, TS 825 provides a technical framework that defines how thermal insulation should be designed and implemented in order to improve energy efficiency and limit heat losses and gains in buildings.
What Is nSEB (Nearly Zero-Energy Buildings)?
nSEB (Nearly Zero-Energy Buildings)refers to buildings that have very low energy demand, are designed to achieve high levels of energy efficiency, and meet a defined portion of their energy consumption through renewable energy sources.
In Türkiye, the criteria for nSEB are defined under the Regulation on Energy Performance in Buildings.
The main requirements for nSEB include:
What Is the Difference Between TS 825 and nSEB?
These two concepts are frequently confused because their overall objectives may appear similar. However, they differ in both purpose and scope.
TS 825 focuses primarily on the thermal insulation performance of a building, whereas nSEB addresses the overall energy performance of the building, including both efficient energy use and the integration of renewable energy sources.
In this respect, nSEB represents a broader concept. While TS 825 emphasizes reducing energy demand through effective thermal insulation, nSEB considers the overall balance between energy consumption, energy efficiency, and renewable energy generation.
The main objective of TS 825 is to minimize the energy required for heating and cooling. The nSEB approach, on the other hand, first aims to reduce the overall energy demand of the building and then to meet a defined portion of the remaining demand through renewable energy sources.
Thermal insulation designed in accordance with TS 825 reduces a building’s overall energy demand. This represents an important step toward meeting nSEB requirements. The better the thermal performance of the building envelope, the lower the building’s energy demand will be, increasing the potential for renewable energy systems to cover a greater share of that demand.
Therefore, compliance with TS 825 is an important foundation for achieving nSEB performance, but it is not sufficient on its own. To qualify as an nSEB, a building must demonstrate both high energy efficiency and the required level of renewable energy use.
Overall, the TS 825 standard and the nSEB approach are two important complementary elements that help improve energy efficiency, minimize heat loss, and strengthen sustainable construction. While TS 825 improves the thermal insulation performance of buildings, nSEB builds on this foundation by incorporating the use of renewable energy sources. When these two approaches are implemented effectively, they enable the development of buildings with lower energy consumption and higher environmental performance.
Considering these two approaches together also creates benefits beyond individual buildings, extending to the neighborhood and urban scale. It can reduce the pressure on infrastructure, help balance energy demand across cities, lower the carbon footprint of buildings, and increase urban resilience to climate change. The combination of these benefits makes a significant contribution to sustainable urban development.
Two Critical Concepts in Energy Efficiency: TS 825 and nSEB
TS 825 and nSEBIn Türkiye, various technical regulations have been introduced to reduce heat loss in buildings, improve energy efficiency, and support sustainable construction. Within this framework, TS 825: Thermal Insulation Requirements for Buildings and the nSEB (Nearly Zero-Energy Buildings) approach play a particularly important role.
Although TS 825 and nSEB are both key tools in achieving sustainable construction goals, they are often confused with one another. While they share similar objectives, they differ significantly in terms of scope and application.
What Is the TS 825 Standard?
TS 825 is a national standard that defines the rules and calculation methods related to thermal insulation in buildings. Developed to reduce heating and cooling energy consumption and improve energy efficiency in buildings across Türkiye, the standard specifies thermal transmittance coefficients (U-values) for building components as well as minimum insulation requirements.
First introduced on 14 June 2000, the standard was updated in 2024 to include revised minimum thermal insulation requirements for different climate zones and calculation methods designed to limit heat loss while taking both heating and cooling energy demand into account.
Unlike previous versions, the updated TS 825 standard evaluates not only heating energy demand but also cooling requirements, providing a more comprehensive approach to building energy performance. In addition, the number of climate zones in Türkiye was increased from four to six.
In summary, TS 825 provides a technical framework that defines how thermal insulation should be designed and implemented in order to improve energy efficiency and limit heat losses and gains in buildings.
What Is nSEB (Nearly Zero-Energy Buildings)?
nSEB (Nearly Zero-Energy Buildings)refers to buildings that have very low energy demand, are designed to achieve high levels of energy efficiency, and meet a defined portion of their energy consumption through renewable energy sources.
In Türkiye, the criteria for nSEB are defined under the Regulation on Energy Performance in Buildings.
The main requirements for nSEB include:
- The building must achieve an energy performance class of at least B.
- At least 10% of the building’s total energy demand must be supplied from renewable energy sources.
What Is the Difference Between TS 825 and nSEB?
These two concepts are frequently confused because their overall objectives may appear similar. However, they differ in both purpose and scope.
TS 825 focuses primarily on the thermal insulation performance of a building, whereas nSEB addresses the overall energy performance of the building, including both efficient energy use and the integration of renewable energy sources.
In this respect, nSEB represents a broader concept. While TS 825 emphasizes reducing energy demand through effective thermal insulation, nSEB considers the overall balance between energy consumption, energy efficiency, and renewable energy generation.
The main objective of TS 825 is to minimize the energy required for heating and cooling. The nSEB approach, on the other hand, first aims to reduce the overall energy demand of the building and then to meet a defined portion of the remaining demand through renewable energy sources.
Thermal insulation designed in accordance with TS 825 reduces a building’s overall energy demand. This represents an important step toward meeting nSEB requirements. The better the thermal performance of the building envelope, the lower the building’s energy demand will be, increasing the potential for renewable energy systems to cover a greater share of that demand.
Therefore, compliance with TS 825 is an important foundation for achieving nSEB performance, but it is not sufficient on its own. To qualify as an nSEB, a building must demonstrate both high energy efficiency and the required level of renewable energy use.
Overall, the TS 825 standard and the nSEB approach are two important complementary elements that help improve energy efficiency, minimize heat loss, and strengthen sustainable construction. While TS 825 improves the thermal insulation performance of buildings, nSEB builds on this foundation by incorporating the use of renewable energy sources. When these two approaches are implemented effectively, they enable the development of buildings with lower energy consumption and higher environmental performance.
Considering these two approaches together also creates benefits beyond individual buildings, extending to the neighborhood and urban scale. It can reduce the pressure on infrastructure, help balance energy demand across cities, lower the carbon footprint of buildings, and increase urban resilience to climate change. The combination of these benefits makes a significant contribution to sustainable urban development.