This paper introduces an open-source analytics framework designed to assist in creating low or net-zero carbon buildings and urban districts. Integrated with URBANopt™, an open-source platform for energy analysis in districts and communities, this framework equips researchers, architects, engineers, and other stakeholders with the necessary tools to evaluate the carbon footprint implications of their design choices.This paper introduces an open-source analytics framework that enables users to design for low or net-zero carbon buildings and urban districts. The framework provides researchers, architects, engineers, and other stakeholders with the tools necessary to understand the impact of their design decisions on buildings’ carbon footprints.

The framework enables the analysis of various scenarios, incorporating both historical and future emission factors, and can span across different climate zones, each with distinct grid and emissions characteristics. We enable the analysis of different scenarios that reflect historical or future scenario emission factors and span across different communities with unique grid and emissions characteristics. The results demonstrate how users can evaluate the impact of design upgrades and controls strategies in the building/community systems and analyze their effects on carbon-emissions at a district-scale.

The results showcase the framework's capability to evaluate the impact of design upgrades and control strategies on carbon emissions in district/community buildings. An analysis using a hypothetical district in Denver, Colorado, showed reduced emissions from energy efficiency upgrades and control strategies, highlighting the sensitivity in their effects on emissions and energy use.

Building energy codes are among the most cost-effective strategies for reducing carbon emissions. In this study, we have enhanced the U.S. DOE’s commercial and residential prototype model frameworks. These were originally designed to support the development of building energy codes based on energy use and cost metrics. Now, we have augmented these frameworks to quantify carbon emissions. This is achieved by simulating hourly building energy usage and utilizing the Cambium hourly emission rates. To integrate these two different geographic scales – the eGrid regions from which the Cambium emission rates are derived, and the ASHRAE climate zones where energy simulations are conducted – we have established quantitative mappings between climate zones and eGrid regions. These mappings are created for both commercial and residential prototype buildings, using commercial construction volumes and residential construction permits, respectively. This approach allows our analysis framework to account for emission rate disparities across various eGrid regions within a particular climate zone, as well as for energy consumption variations in buildings with different functionalities

This research investigates the ecological and microclimatic implications of implementing green façade systems in a residential district. The evaluation is grounded in a Life Cycle Assessment that scrutinizes greenhouse gas emissions, encompassing both the material life cycle and transportation aspects. Complementarily, the study employs a Microclimatic Analysis utilizing the Universal Thermal Climate Index to elucidate microclimatic conditions, considering the variations in plant and construction selections. The findings show that certain green façade configurations contribute to a reduction in emissions and an enhancement of microclimatic conditions, thereby suggesting a potential for synergistic integration within urban planning frameworks. This investigation underscores the efficacy of green façade applications in fostering urban sustainability and accentuates the necessity of harmonizing environmental considerations with microclimatic factors in urban planning decision-making processes.

The future climate significantly impacts building performance and increases uncertainties in energy simulations. A rising temperature trend is expected to heighten cooling loads during summer and result in more carbon emissions. Understanding the impact of future climate on building performance is significant for policymakers to make informed decisions. Building retrofit measures can improve building energy efficiency and reduce operational carbon emissions, yet their effects under future climate conditions have not been fully investigated so far. Thus, we proposed an assessment methodology for evaluating long-term energy consumption and operational carbon reduction potential using a building stock dataset. For this study, commercial buildings in the northwestern (NW) region were utilized to assess the impacts of future climate and building retrofit. In addition, we selected Montana with a cold and dry climate as an example to analyze and discuss the carbon emission reduction potential in buildings. The main findings are: (1) Under future climate trends, changes in energy use intensity (EUI) will fluctuate due to variations in heating and cooling degree-days (HDDs and CDDs) and increasing HDDs will lead to increasing EUI. (2) After applying annual building retrofitting, the long-term EUI reduction potential of buildings in the NW region will decrease with the increasing retrofitting degree, and the short-term EUI reduction potential will be impacted by the change of heating and cooling degree days. (3) In Montana, the long-term carbon intensity reduction potential of retrofitted buildings will decrease under future climate trends with the increasing renewable energy penetration.