Shaping the Energy Efficiency in New Buildings - Building Energy ...

there are also certain mandatory requirements that must be met regardless of anyalternative options. The approach to building performance varies between APPcountries. The United States employs an energy/cost/budget method, which is anenergy cost-based type of building performance that differs from other energyconsumption-based building performance approaches. Japan and South Korea employ a scoring or point approach, which fallssomewhere between a trade-off and performance approach. In Japan’scommercial code, each section of the code is scored separately, making it moreakin to the trade-off alternatives in countries with prescriptive requirements.Japan’s commercial and residential codes both also have performancerequirements based on energy consumption per square meter. In South Korea, allthe requirements in the building energy code are scored together, making it morelike a performance approach. South Korea also has prescriptive insulationrequirements in its general building code. China has adopted a hybrid approach: first, the building performance approach isused to determine the difference in energy consumption between a designed and areference building, then the difference is adjusted using the trade-off approach.Australia lists two types of building performance approaches for buildings. For dwellings,the thermal calculation method is employed to comply with the Australian BuildingCodes Board’s Protocol for House Energy Rating Software. Each dwelling unit has anenergy rating of not less than 3 stars. For commercial buildings, the codes set maximumregional annual energy allowances (in megajoules per square meter) by fuel and buildingtypes, with a separate section devoted to the methodology to calculate annual energyconsumption. There are also provisions for trade-offs and a building performanceapproach for houses.China’s commercial building energy codes combine the performance approach and tradeoffapproach. First, annual energy consumption is calculated and compared for heatingand cooling of a reference and designed building. Second, the trade-off approach is usedonly if the value of a designed building is higher than the reference case. A similarcombination approach also applies for residential building codes.Japan’s and South Korea’s building energy codes for commercial buildings adopt ascoring approach: the desired measures that lead to higher building energy efficiency arescored with higher points. Differing from its commercial building energy codes, Japan’sresidential building energy codes have prescriptive measures instead of scored ones,though with both the residential and commercial codes in Japan, there are performancebasedmetrics as well.South Korea has a recommended building energy efficiency rating system based on theperformance approach. However, in some areas such as new towns, municipalgovernments may require that their new buildings obtain a higher level label for energyefficiency than specified in the building code. In addition, South Korea is preparing anew performance-based code which sets requirements for maximum annual energy usage.Accordingly, after 2010, buildings over 10,000 square meters will be required to submitannual energy consumption and a CO 2 emission report to the government. Thesedocuments must be calculated by the performance approach.55