New Construction Research Articles

Energy and Greenhouse Gas Savings for LEED-Certified U.S. Office Buildings

In this work, we present results from the largest study of measured, whole-building energy performance for commercial LEED-certified buildings, using 2016 energy use data that were obtained for 4417 commercial office buildings (114 million m2) from municipal energy benchmarking disclosures for 10 major U.S. cities. The properties included 551 buildings (31 million m2) that we identified as LEED-certified. Annual energy use and greenhouse gas (GHG) emission were compared between LEED and non-LEED offices on a city-by-city basis and in aggregate. In aggregate, LEED offices demonstrated 11% site energy savings but only 7% savings in source energy and GHG emission. LEED offices saved 26% in non-electric energy but demonstrated no significant savings in electric energy. LEED savings in GHG and source energy increased to 10% when compared with newer, non-LEED offices. We also compared the measured energy savings for individual buildings with their projected savings, as determined by LEED points awarded for energy optimization. This analysis uncovered minimal correlation, i.e., an R2 < 1% for New Construction (NC) and Core and Shell (CS), and 8% for Existing Euildings (EB). The total measured site energy savings for LEED-NC and LEED-CS was 11% lower than projected while the total measured source energy savings for LEED-EB was 81% lower than projected. Only LEED offices certified at the gold level demonstrated statistically significant savings in source energy and greenhouse gas emissions as compared with non-LEED offices.

“Embodied and Operational Carbon of Typical Heating, Ventilation and Air Conditioning (HVAC) Systems in Office Buildings in Washington State: A study of buildings registered under LEED v3 2009”

Heating, Ventilation and Air Conditioning (HVAC) systems contribute significantly to operational energy and CO2e emissions during the service life of office buildings. Over the last decade, stringent energy codes have enabled the introduction of new HVAC technologies to reduce operational CO2e emissions. However, life cycle carbon emissions of buildings are odivided into operational carbon (OC) and embodied carbon (EC). Operational carbon are the CO2e emissions generated from the burning of fossil fuels used to heat, cool and power the building space during its service life, while EC encompasses the CO2e emissions equivalent to producing, procuring, installing, mantaining, repairing and disposing of the materials and components that make up the building. Over the last decade, broad efforts have improved the understanding of the role that HVAC system selection play in overall OC, nevertheless, EC of HVAC has remained unexamined This paper aims to identify typical HVAC systems used in office building design in Washington State and explore the effects of current practice on total energy use, operational and embodied CO2e. The study sample is composed of twenty office buildings in Washington State registered under the LEED v3 2009 version, from which 15 have obtained LEED certification in the last two years. The projects are registered under the New Construction (NC), Core and Shell (CS), Existing Buildings and Operation and Maintenance (EB:OM) and Commercial Interiors (CI) products and comply with the requirements established in the ASHRAE 90.1-2007 energy standard. The results show that typical HVAC system selection is often a combination of different technologies for ventilation, heating and cooling, and that in general: smaller buildings tend to incorporate high efficiency packaged units while medium and large size buildings typically rely on High Performance Variable Air Volume (HPVAV) systems or hydronic systems such as chilled beams and water source heat pumps (WSHP). The results also indicate that data available through the LEED v3 2009 documentation system on embodied carbon of the mechanical systems is limited and that simplified methods to assess embodied carbon of HVAC are needed in order to integrate EC into whole life assessment of Mechanical Systems.

Technical Evaluation of LEED-v4.1-(BD+C: NC) for Rating and Certification of Sustainable New Construction Outside the USA

Worldwide, all the current sustainable rating and certification systems are targeting fair and applicable rating criteria and conditions to best matching the circumstances and sustainable needs of every nation for their environmental conditions, equity needs, and economic concerns. This paper is made to evaluate and measure the compliance of LEED-v4.1-(BD+C: NC) sustainable rating and certification system [1] with the sustainability concerns of the new construction (NC) market outside the USA through considering Egypt as an example and conducting a detailed comparative analysis between the LEED-v4.1-(BD+C: NC) sustainable rating and certification system [1] and the authors' proposed sustainable rating and certification system for new construction in Egypt (Bonna (2018) [2]), to highlight most of the missing sustainability rating credits/issues which are necessary for Egypt and not found within the LEED-v4.1-(BD+C: NC) rating system [1]. Zuo and Zhao [3] emphasized that the green buildings in different countries are designed and built according to local climatic conditions and to suit the requirements of the locals and therefore, the assessment criteria for these green buildings are different.

The Impact of Engineering Quality on Rating of Sustainable New Construction: A Major Influence

This paper is made to describe the major impact and influence of the engineering quality achieved in new construction (NC) on their sustainable rating outcomes by performing a complete overview of the intent of engineering quality within the main categories and their related mandatory & scoring credits of the proposed sustainable rating & certification system for new construction in Egypt presented by the accredited Ph.D. research (Bonna (2018) [1]) made by the above authors for the purpose of promoting the sustainable building practices and embracing the potential of green buildings in Egypt. The total quality assessment (TQA) systems evaluate ecological, economic and social aspects with criteria organized into categories including resource consumption, harmful impacts on humans & environment, comfort, longevity, safety & security, design/planning quality, construction quality, quality of amenities & site, and economics (Hastings and Wall (2007) [2]). The proposed system's main categories and their related credits which have technical scope related to engineering quality, as described below, are based on the TQA main parameters which can help in better sustainable quality deliverables of new construction projects including the environmental quality, social quality, and economical quality.

The GPRS-V2-2017-NB National Rating System of Sustainable New Buildings and Major Renovation: A Technical Evaluation

Worldwide, all the current sustainable rating systems are targeting fair and applicable rating criteria and conditions to best matching the circumstances and sustainable needs of every nation for their environmental conditions, equity needs, and economic concerns. This paper is made to evaluate and measure the compliance of GPRS-V2-2017-NB (GPRS (2017) [1]), which is the Egyptian national rating system for sustainable new buildings and major renovation, with the sustainability concerns of the new construction (NC) market in Egypt through conducting a comparative analysis between this system and the authors' proposed sustainable rating & certification system for new construction in Egypt (Bonna, Hazem, R. (2018) [2]) to highlight most of the missing sustainability rating credits/issues which are necessary for Egypt and not found within the GPRS-V2-2017-NB rating system. Fowler and Rauch [3] performed a comparative analysis of five international green building rating systems to check their compliance criteria to rate green projects inside USA, where the authors concluded that BREEAM was inapplicable to all the U.S. General Services Administration (GSA) project types, CASBEE employment in GSA building classification is not possible, and LEED was the only rating system that is applicable to all GSA project types.

A Comparative Analysis of Gold Leadership in Energy and Environmental Design for New Construction 2009 Certified Projects in Finland, Sweden, Turkey, and Spain

The Leadership in Energy and Environmental Design (LEED) is currently intensively applied in several European countries. The aims of the present study were to compare the difference between (i) two countries from the same region (i.e., Finland vs. Sweden or Turkey vs. Spain) and (ii) two European regions (northern Europe [Finland and Sweden] vs. [Turkey and Spain]) when the LEED- New Construction (NC) 2009 Certified rating level certified projects were analyzed. We found that, in the northern and southern parts of Europe, LEED- NC 2009 credit achievements in terms of Sustainable Sites (SS), Water Efficiency (WE), Materials and Resources (MR), and Indoor Environmental Quality (EQ) were similar, whereas credit achievements in Energy and Atmosphere (EA) were different. High achievements were revealed in WE and SS, with values of 80–100% and 70–75%, respectively; intermediate achievements were revealed in EQ, with values of 40–60%; and low achievements were revealed in MR (20–40%). EA achievements were intermediate (60–65%) in northern Europe, while they were low in southern Europe (40%). This evidence can help recognize the categories that are performed with a high number of points and those that are performed with a low number of points.

Incentivizing the Daylit Hospital: The Green Guide for Health Care Approach

Daylight is usually mentioned immediately after reduced energy use in conversations about sustainable building design, yet in North America, daylight remains the most-asked-for/least-delivered aspect of the caregiver work environment. In Europe, essentially the same care practices continue to be accommodated in daylit building configurations. Recognizing that the daylighting credits in Leadership in Energy and Environmental Design (LEED) for new construction (NC) are more difficult for large healthcare projects to achieve during the design process, and that two daylighting credits are probably not enough of an incentive to change North American healthcare design practice, the Green Guide for Health Care (GGHC) has both simplified the process of calculating daylight achievement levels and increased the number of daylighting credits available from two to five.