% ============================================================================ % UQO Working Paper No. 20 — From Listing Images to Property Valuation % ============================================================================ \documentclass[12pt,letterpaper]{article} % --- Encoding & Language --- \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[english]{babel} % --- Page Layout --- \usepackage[letterpaper,top=1in,bottom=1in,left=1in,right=1in]{geometry} % --- Typography --- \usepackage{mathptmx} \usepackage{microtype} \usepackage{setspace} \onehalfspacing % --- Math --- \usepackage{amsmath,amssymb,amsthm} \theoremstyle{plain} \newtheorem{proposition}{Proposition} \theoremstyle{definition} \newtheorem{assumption}{Assumption} \newtheorem{definition}{Definition} \theoremstyle{remark} \newtheorem{remark}{Remark} % --- Tables --- \usepackage{booktabs} \usepackage{tabularx} \usepackage{multirow} \usepackage{threeparttable} \usepackage{siunitx} \sisetup{input-symbols = {()}, table-format = -1.3, parse-numbers = false} \usepackage{array} \usepackage{adjustbox} % --- Figures --- \usepackage{graphicx} \graphicspath{{figures/}} \usepackage{subcaption} \usepackage{float} \usepackage{tikz} \usetikzlibrary{arrows.meta,positioning,shapes.geometric,fit} % --- Colors & Links --- \usepackage[dvipsnames]{xcolor} \usepackage[colorlinks=true,linkcolor=NavyBlue,citecolor=NavyBlue,urlcolor=NavyBlue,breaklinks=true]{hyperref} % --- Bibliography --- \usepackage[authoryear,round,semicolon]{natbib} \bibliographystyle{aer} % --- Captions --- \usepackage[font=small,labelfont=bf,labelsep=period,justification=justified,singlelinecheck=false]{caption} % --- Headers & Footers --- \usepackage{fancyhdr} \pagestyle{fancy} \fancyhf{} \renewcommand{\headrulewidth}{0pt} \fancyfoot[C]{\thepage} % --- Section Formatting --- \usepackage{titlesec} \titleformat{\section}{\large\bfseries}{\thesection.}{0.5em}{} \titleformat{\subsection}{\normalsize\bfseries}{\thesubsection.}{0.5em}{} \titleformat{\subsubsection}{\normalsize\itshape}{\thesubsubsection.}{0.5em}{} % --- Appendix Support --- \usepackage[toc,page]{appendix} % --- Misc --- \usepackage{enumitem} \setlist{nosep,leftmargin=*} \usepackage{url} % --- Generated numbers (every figure quoted in the text) --- \input{tables/numbers} % ============================================================================ % METADATA % ============================================================================ \newcommand{\WPnumber}{20} \newcommand{\WPtitle}{From Listing Images to Property Valuation: A Multimodal AI Framework for Automated Building Characterization and the Cost Approach} \newcommand{\WPsubtitle}{Evidence from Québec single-family listings matched to the assessment roll} \newcommand{\WPdate}{October 2026} \newcommand{\WPversion}{1.0} \newcommand{\WPabstract}{% The cost approach to value requires a specification of the improvements---materials, finish grade, condition, renovations---that assessment rolls do not record and that appraisers obtain by inspection. We ask whether that specification can be extracted from the photographs and text of a for-sale listing by general-purpose vision--language models, and what a transparent cost indication built on it is worth. We formalise an extraction-to-valuation framework with five evidence classes (administrative, visual, proxy, text-claimed, latent), deterministic cross-image aggregation, text--image--record reconciliation, a fully sourced cost schedule and uncertainty propagation, and we apply it to \nSample{} Québec house listings matched within 15~m to their roll unit (\nImagesSample{} photographs, three extractor tiers, \nRefsVerified{} verified references). Visible exterior attributes are extracted with high agreement against broker fields (roof covering \accroofcovering\%, garage type \accgaragetypeattacheddetached\%, cladding \acccladdingprimarybrokersidings\%) but storeys agree with the roll only loosely ($\kappa=\kappastoreysvisible$), and the most cost-relevant interior evidence is simply not shown: within the first ten photographs, \shownBasement\% of listings show a basement and \shownBathroom\% a bathroom, a missing-not-at-random structure that no extractor can overcome. Relative to a roll-only baseline, image and text attributes raise the median cost indication and move its ratio to the asking price from \priceRatiosonnetBZeroB{} to \priceRatiosonnetBThreeB{} (median absolute deviation \priceMdapesonnetBZeroB\% to \priceMdapesonnetBThreeB\%), mainly through condition-adjusted depreciation; the gain is real but modest, and the level of the indication depends more on the published unit-cost anchor than on anything seen in the images. A calibration against assessor building values on five metropolitan areas transfers to a geographic hold-out and implies a hard cost near \$300 per square foot, consistent with 2026 Québec industry guides and well above a Montréal hard-cost band. We release the ontology, prompts, schedule and code, and we are explicit about what the data cannot establish: no expert labels exist, latent defects are unobservable, and the cost indication is a screening tool, not an appraisal.% } \newcommand{\WPkeywords}{cost approach, automated valuation, vision--language models, listing photographs, depreciation, assessment roll, Québec} \newcommand{\WPjel}{R31, R32, C45, C55, D83} % --- Author --- \newcommand{\WPauthor}{Simon-Pierre Boucher} \newcommand{\WPaffiliation}{Département des sciences administratives\\ Université du Québec en Outaouais} \newcommand{\WPemail}{simon-pierre.boucher@uqo.ca} \newcommand{\WPaddress}{Gatineau -- Pavillon Alexandre-Taché\\ 283, boulevard Alexandre-Taché\\ Gatineau, Québec, Canada J9A 1L8} \hypersetup{pdftitle={From Listing Images to Property Valuation: A Multimodal AI Framework for Automated Building Characterization and the Cost Approach},pdfauthor={Simon-Pierre Boucher}} % ============================================================================ \begin{document} \input{sections/titlepage} \input{sections/introduction} \input{sections/setting} \input{sections/literature} \input{sections/framework} \input{sections/data} \input{sections/methodology} \input{sections/results_extraction} \input{sections/results_cost} \input{sections/robustness} \input{sections/discussion} \input{sections/limitations} \input{sections/conclusion} \newpage \bibliography{references} \input{appendix/appendix} \end{document}