The Korean Government also has made a significant effort to develop and enforce policies regarding regulations, certification system, financial support, and technical development. Since the 1980s, a number of policies have been adopted to improve building energy conservation in Korea, including the Building Energy Conservation Code (BECC) in the 1980s, the Regulations for Energy Efficiency Labeling and Standards in the 1990s, the Green Building Certification program and the BEECS in the early 2000s. The Korean government announced several major government projects in August of 2008, including their provision of a million green houses, in an effort to further their new vision of Low Carbon and Green Growth [
22,
23,
24]. This Green Growth aims at establishing a new paradigm that is expected to shift the current conflictive relationship between environmental protection and economic growth to one of cooperation; this will be accomplished by creating a new job market (and accomplishing other related goals) that responds to climate change and the current energy crisis [
25]. This policy of Low Carbon and Green Growth hopes to switch the human population from a vicious to a virtuous cycle in terms of energy, the economy, and the world’s climates and ecosystems; it aims to develop a new paradigm of balance between economic development and environmental conservation [
22,
23,
24]. To further these goals, the Korean government’s Ministry of Land, Infrastructure, and Transport (MOLIT) announced an “Activation Plan for Green Building” in November of 2009. The government’s aim is to keep updating building codes gradually such that by 2025 all newly constructed buildings will be zero-energy buildings [
24]. This is one significant reason why energy conservation policies in the building sector should now be consistently followed.
The Activation Plan for Green Building, announced in 2009, carries an especially important meaning for green buildings and building energy policy. This was the first plan to integrate a number of policies designed to promote the spread of green buildings and building energy conservation in Korea into a national vision for general conservation. Before this plan, each building’s energy conservation policy was implemented on an individual basis. MOLIT proposed a refined policy for promoting green buildings in 2011, and then enacted the Green Building Development Support Act in 2012; it was first enforced in February of 2013. MOLIT also furthered green building policies by establishing the Green Architecture Division in March of 2012, and designating the Korea Energy Agency (KEA), the Korea Institute of Construction Technology (KICT), the Korea Infrastructure Safety and Technology Corporation (KISTEC), the Korea Appraisal Board (KAB), and the Korea Research Institute for Human Settlements (KRIHS) to act as green building centers for the development and execution of a number of related policies. In addition, the Korean government announced its first green building master plan in December of 2014, which includes a five-year plan containing strategies for promoting the development of green buildings. By 2020, the government expects this plan to reduce the country’s production of greenhouse gases in the building sector by 26.9% [
24].
3.1. Building Energy Conservation Code
The BECC is a mandatory regulation to specify minimum requirements for building energy performance. The BECC has both prescriptive and performance approaches. In its prescriptive approach, the Code specifies a set of mandatory design criteria for the four main building sections (building envelope, mechanical systems, electrical systems, and renewable energy systems) as well as an evaluation of the Energy Performance Index (EPI) [
27]. In its performance approach, buildings are not yet mandated to meet the established criteria but it is recommended that builders evaluate the energy consumption levels of their designs according to ISO 13790 when constructing office buildings above 3,000 m
2 total floor area. In order to obtain a construction permit, a building energy conservation plan complying with specific design criteria, an EPI evaluation sheets, and energy consumption calculation results must all be submitted according to building type. The target building types for submissions have been expanded year by year, as shown in
Figure 4. Even though a public bath and a swimming pool were not common typologies, they were included in the target building types due to high energy consumptions. A dormitory was also considered separately from a multifamily residential building since its energy consumption profile was much more similar to lodging. Since September 2013, obligation to submit energy conservation plans have been expanded to all types of residential and non-residential buildings above 500 m
2 total floor area.
Figure 4.
Expansion of building types for submission of building energy conservation plans.
Figure 4.
Expansion of building types for submission of building energy conservation plans.
Each relevant institution has an assigned role. MOLIT announces the BECC, and KEA manages the practical aspects of the system by analyzing data, maintaining online review systems, developing guidelines, advertising, educating mandating authorities and architectural firms, and examining review outputs from other review institutions. The review process for building energy conservation plans is shown in
Figure 5.
Figure 5.
Review process of a building energy conservation plan.
Figure 5.
Review process of a building energy conservation plan.
The building energy conservation plan consists of three paths: energy conservation design criteria, EPI evaluation, and energy consumption calculation. All building types described in
Figure 4 should comply with the first two prescriptive paths. Office buildings with above 3000 m
2 of total floor area are required to comply with not only the prescriptive paths but also the performance-based energy consumption calculation.
First, nineteen criteria that comprise the architectural, mechanical, and electrical sectors of the building are obliged to meet specific design criteria. An example of the detailed list can be found in
Table 3. According to the heating degree-days, insulation criteria for building envelope are classified into three climate zones; the central zone, the southern zone, and Jeju Island [
27]. The U-value for each part of the building envelope is required to meet certain criteria, unless insulation beyond a certain thickness and of a certain performance quality is installed. In order to avoid heat loss from excessively large window areas, the criteria also regulate the average U-value for the whole building envelope. In Korea, because most residential buildings have underfloor radiation heating systems, the regulations also require the installation of insulation on the floor between the bottom of hot water pipes and the material beneath in order to minimize heat loss downwards. Moreover, an automatic standby power cut-off device must be installed for more than 30% of electric outlets, and whole house-off switches must be installed either by floor or by zone. For public buildings, shading devices are required, and more than 60% of total cooling systems capacity should be covered by alternative power cooling systems such as gas turbine cooling systems, small cogeneration systems, or renewable energy systems instead of electricity. The requirement for alternative power cooling systems was originally applied for public buildings above 3000 m
2 and was extended to buildings above 1000 m
2 in 2013. It was intended to promote the use of alternative power cooling systems for ensuring that power supply problems were not incurred by peak load in summer.
Secondly, the Energy Performance Index (EPI) is also a prescriptive compliance path which comprises 50 evaluation criteria within the architectural, mechanical, electrical, and renewable sectors. The EPI score is calculated as the sum of the credits obtained from each sector, with corresponding weighting. This type of evaluation method is also used for Korean green building certification systems, Green Standard for Energy and Environmental Design (G-SEED). The mechanical sector has the greatest number of evaluation criteria, followed by the electrical, architectural, and renewable sectors, in that order. However, the architectural sector offers the most possible credits, followed by the mechanical, electrical, and renewable sectors, in that order.
In order to get a construction permit, more than 65 of the 120 total credits must be obtained (this was 60 until September 2013); for public buildings, the minimum is 74. According to the analysis of office building samples from the submitted building energy conservation plan from 2008 through 2013, 57 percent of the buildings were able to obtain slightly more than 60 credits, and 25 percent of the buildings were able to obtain above 70 credits (see
Figure 6). The reason for this could be either that the buildings were designed to be barely beyond the baseline necessary to obtain a construction permit, or the buildings were already beyond the baseline for the permit so the building owners simply did not apply for the additional credits they could have obtained.
The most current of this information is used for inputs when running building energy simulations for the BEECS. The BECC has been enacted since the 1980s to minimize the energy consumption of newly constructed buildings. It has regularly been strengthened to target zero-energy buildings that will be built after 2025. In 2009, the Korean government announced that after 2017, they would require building envelope criteria to be up to the level of passive buildings. Accordingly, the criteria have been strengthened every two years. In addition, the government plans to revise the criteria to determine a rational thickness for insulation in building envelopes, as well as provide integrated criteria such as thermal bridge, airtightness, and solar control devices.
Table 3.
Mandatory energy design criteria of building energy conservation plan.
Table 3.
Mandatory energy design criteria of building energy conservation plan.
Sector | Mandatory Criteria |
---|
Architecture | Comply with U-value for walls, roofs, floors, windows, doors, etc. |
Comply with area-weighted average U-value for walls, windows, and doors |
Comply with insulation method for underfloor heating/installation of vapor barriers |
Install airtight windows |
Install solar control devices (only for public buildings) |
Mechanical system | Comply with design outdoor temperature and humidity for HVAC load calculation |
Install Korean Standard (KS)-certified pumps or high-efficiency pumps |
Comply with insulation requirements for ducts and pipes |
Install alternative power cooling system (only for public buildings above 1,000m2) |
Electrical system | Install high-efficiency transformers |
Install power-factor improvement condensers |
Install high-efficiency lighting/circuits for partial lighting |
Install certified high-efficiency LED lighting for parking lots and for emergency exit signs |
Install automatic illumination control systems in entrances of each residential unit |
Install whole house-off switch |
Install automatic standby power cut-off devices for more than 30% of electric outlets |
Figure 6.
EPI scores of office buildings in 2008–2013 (Number of samples = 343).
Figure 6.
EPI scores of office buildings in 2008–2013 (Number of samples = 343).
Lastly, in order to make up for the weak prescriptive approach of the building energy code, a performance approach has been test-operated for office buildings with above 3000 m
2 of total floor area. It is mandatory for these buildings to submit the calculated energy consumption for heating, cooling, domestic hot water, ventilation, and lighting by use of an official building energy simulation program, ECO2-OD [
28]. Until now, there is no specific requirement for calculated energy consumption, but its performance criteria are due to be suggested in near future. Additionally, this approach is expected to be expanded to various types of buildings.
3.2. Building Energy Efficiency Certification System
Figure 6 shows that most of the buildings were designed to be barely beyond the baseline of the mandatory design criteria. In order to promote the spread of high energy-efficient buildings, the system that could evaluate and certify energy performance of buildings other than the minimum design criteria should be required. Therefore, the BEECS was established to promote energy conservation in buildings and encourage energy efficient technologies by providing information on building energy consumption and GHG emission. The Ministry of Trade, Industry, and Energy (MOTIE) began the certification process in 2001 for new multifamily residential buildings. The certification system was expanded to new office buildings in 2010, and then to all types of buildings in 2013.
The first version of calculation tool for the BEECS was developed for multifamily residential buildings only. It was based on the variable heating degree-days method which has a similar concept with a heating degree days, but considers internal heat gains as well as a balance point temperature, the outdoor temperature required for space heating. This method has been widely adopted in other evaluation systems as well for calculating heating energy demand in residential buildings, including ISO 9164, SAP (Standard Assessment Procedure) in the United Kingdom, and HERS (Home Energy Rating System) in the United States.
The evaluation was performed by comparing the calculated heating energy consumptions of a residential building complex with those of the reference residential building complex. Through this comparison, a preliminary certification could be issued according to the energy saving ratio of the applied complex against the reference complex. Equations (1)–(3) show how to calculate energy saving ratio of a household, a residential building, and a residential building complex that applied for the certification.
where,
- ERh:
energy saving ratio of a household in a residential building (%)
- ERb:
energy saving ratio of a residential building (%)
- ERt:
total energy saving ratio of a residential building complex (%)
- Eref:
calculated heating energy consumption for a household in a reference residential household (GJ/year)
- Eh:
calculated heating energy consumption for a household that applied for the certification (GJ/year)
- ERah:
additional energy saving ratio of a household by use of designated energy conservation measures (%)
- ERab:
additional energy saving ratio of a residential building by use of designated energy conservation measures (%)
- Ah:
floor area for a household (m2)
- Ab:
total floor area for a residential building (m2)
- At:
total floor area for a residential building complex that applied for the certification (m2)
The preliminary certified residential building complex could be evaluated again to obtain a final certification after the completion of construction by confirming whether the energy saving measures were applied to the buildings appropriately and examining the infiltration rate (ACH) of a representative household through the blower door test. The energy saving ratio calculated from the equations above was used for determining the certification label, and the criteria was changed in 2010 as shown in
Figure 7. From 2001 to 2009, buildings with energy savings ratios above 33.5% could earn Label 1, but the minimum requirement for Label 1 has been strengthened to 50% of energy savings ratios since 2010.
Figure 7.
Previous criteria of the BEECS for residential buildings.
Figure 7.
Previous criteria of the BEECS for residential buildings.
However, this method was not suitable for non-residential buildings since it only focused on heating energy consumption and could not reflect actual energy consumption in buildings in detail. Consequently, a new calculation software program, ECO2, was developed in 2010 to calculate energy consumptions for heating, cooling hot water heating, lighting, and ventilation in non-residential buildings [
10]. Since May 2013, this method replaced the previous variable heating degree-days method for residential buildings as well.
In this program, building energy consumption is estimated by monthly calculation methodology in accordance with the ISO 13790 [
29], which is considered sufficiently accurate for application in energy certification [
30]. First, heating and cooling energy needs are calculated by considering various parameters regarding building envelopes, internal loads, user schedules, air change rates,
etc. Heating and cooling energy needs are defined as heat to be delivered to or extracted from a conditioned space to maintain the intended temperature conditions during a given period of time [
29]. Secondly, annual energy use for heating and cooling of buildings can be calculated considering HVAC systems and renewable energy systems (PV, solar thermal, and geothermal systems). Finally, annual primary energy consumptions are derived from annual energy use by the application of primary energy conversion factors in Korea: electricity 2.75, gas 1.1, district heating 0.728, and district cooling 0.937.
With the adoption of this new calculation method and software, the labelling criteria were also modified as shown in
Table 4. There are ten labels of certification from 1+++ to 7, according to the total primary energy consumption from heating, cooling, domestic hot water, lighting, and ventilation by building types.
Since 2004, the Korean government has required new multifamily residential buildings constructed by public institutions to acquire a certificate, and since 2008, those certificates were required to be at least Label 2. In 2010, the mandatory requirement was expanded to public office buildings, and since September of 2014, all public buildings above 3000 m2 of total floor area must acquire at least a Label 1 certificate. Multifamily residential buildings constructed by public institutions are obligated to have at least a Label 2 certificate.
Table 4.
Modified Criteria for the BEECS.
Table 4.
Modified Criteria for the BEECS.
Label | Annual Primary Energy Consumption (kWh/m2a) |
---|
Residential Building | Non-Residential Building |
---|
1+++ | Under 60 | Under 80 |
1++ | More than 60 and under 90 | More than 80 and under 140 |
1+ | More than 90 and under 120 | More than 140 and under 200 |
1 | More than 120 and under 150 | More than 200 and under 260 |
2 | More than 150 and under 190 | More than 260 and under 320 |
3 | More than 190 and under 230 | More than 320 and under 380 |
4 | More than 230 and under 270 | More than 380 and under 450 |
5 | More than 270 and under 320 | More than 450 and under 520 |
6 | More than 320 and under 370 | More than 520 and under 610 |
7 | More than 370 and under 420 | More than 610 and under 700 |
The BEECS is supervised by a partnership of the MOLIT and the MOTIE. The KEA provides executive management and accredited nine certification bodies conduct the assessment and issue the certificate. The certification is divided into two steps, a preliminary and a final. The energy efficiency label of the preliminary certification is determined by an evaluation of the design documents during either design or construction phases, while that for the final certification is determined through an evaluation of the as-built documents and a field inspection after completion. The certification process is shown in
Figure 8.
Figure 8.
Building Energy Efficiency Certification process.
Figure 8.
Building Energy Efficiency Certification process.
An owner or constructor can benefit from the certification. First, depending on the energy efficiency label, there may be local tax exemptions for the acquisition tax and the annual property tax on ownership of the building. An owner can be exempt from 5% to 15% of the acquisition tax (this began in January of 2010), and from 3% to 15% of the property tax (this began in January of 2011). Second, a preliminary certificate can mitigate the regulations affecting the building design. Local government regulations, such as a limitation on the maximum floor area ratio, landscaping area, and building height, can be mitigated by 4%–12%. In this case, the label of the final certification should be equal to or higher than the label of the preliminary certification. Third, construction companies can earn an additional point in the prequalification evaluation of bidders for public construction works ordered by the Public Procurement Service, which is responsible for purchasing goods and services including construction works on behalf of public organizations in Korea.