2026-10-202026-10-202026-07-17SOUSA , Leonardo de, MIRANDA, Gustavo Coelho. Estimativa preliminar de quantitativos e orçamentos com LLMs. Orientador: Felipe Moreira de Sá. 2026, 24 f. Trabalho de Curso (Bacharelado em Engenharia Civil) – Faculdade de Engenharia Civil, Instituto de Tecnologia, Universidade Federal do Pará, Belém, 2026. Disponível em:https://bdm.ufpa.br/handle/prefix/10395 . Acesso em:.https://bdm.ufpa.br/handle/prefix/10395Preliminary quantity and cost estimation is relevant to the feasibility assessment of construction projects, but it is developed under incomplete technical information. This study evaluated the applicability of a generative artificial intelligence tool based on a large language model (LLM) for estimating construction service quantities for a social housing development and assessing their impact on the budget. The applied, quantitative and comparative study was conducted as a case study involving 25 single-storey houses in Ibiraiaras, Rio Grande do Sul, Brazil. Based on pre-design assumptions, a quantitative work breakdown structure was generated, reconciled with the executive budget, and valued using equivalent unit costs. Optimistic, primary, and pessimistic scenarios were compared with the reference executive budget. The executive budget totaled BRL 3,453,894.98, while the estimated scenarios reached BRL 3,044,185.96, BRL 3,185,622.90, and BRL 3,644,414.71, respectively. Results showed better agreement for services with direct geometric interpretation, but relevant deviations for installations, roof work, superstructure, painting, and external items. The executive budget was encompassed by the range formed by the three scenarios, indicating that the method can support early feasibility decisions. It is concluded that LLMs can organize an initial estimate and identify review priorities, but they do not replace detailed quantity takeoff and executive cost estimation based on complete technical documentation.Acesso AbertoInteligência artificial generativaModelos de linguagem de grande porteQuantitativos de serviçosHabitação de interesse social.Estimativa de custosGenerative artificial intelligenceLarge language modelsConstruction quantitiesCost estimationSocial housing.CNPQ::ENGENHARIAS::ENGENHARIA CIVILTrabalho de Curso - Graduação - ArtigoAttribution-NonCommercial-NoDerivs 3.0 Brazil