This document reviews and compares various domestic carbon accounting tools for assessing the carbon footprint of buildings, based on a case study of a Passive House. It analyzes tools such as the Athena Impact Estimator, Basic Freight Modelling Calculator, EcoTransit, RICS SMM7, and others. For each tool, it provides details on how it works and calculates carbon emissions, and evaluates its strengths and limitations for domestic building carbon assessment. In general, it finds that the tools provide varied levels of accuracy and customization, with many relying on approximations, limited construction options, or non-domestic data that impact their suitability for UK building carbon analysis.