Citation: Pandey, S.P.; Yu, H.; Lau, C.; Ng, K. New Coal Char-Based Building Products: Manufacturing, Engineering Performance, and Techno-Economic Analysis for the USA Market. Sustainability 2024, 16, 1854. https://doi.org/10.3390/ su16051854 Academic Editors: Amit Kenny and Mert Yücel Yardımcı Received: 19 January 2024 Revised: 10 February 2024 Accepted: 20 February 2024 Published: 23 February 2024 Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Article New Coal Char-Based Building Products: Manufacturing, Engineering Performance, and Techno-Economic Analysis for the USA Market Suraj Prasad Pandey , Hua Yu , Chooikim Lau and Kam Ng * Department of Civil and Architectural Engineering and Construction Management, University of Wyoming, Laramie, WY 82071, USA; spandey1@uwyo.edu (S.P.P.); hyu3@uwyo.edu (H.Y.); clau1@uwyo.edu (C.L.) * Correspondence: kng1@uwyo.edu Abstract: Common building products, i.e., thin brick and stone veneer, add the look of brick walls or the enduring charm of natural stones into buildings and houses without imposing a substantial increase in structural load. This study investigates the mechanical strength, durability, and economic feasibility of producing innovative char-based thin bricks and stone veneers. The char-based thin brick vacuum treated with hydrophobic liquid exhibits water absorption rates within the 4–7% range, displays durability against 50 freeze–thaw (F-T) cycles, and maintains a saturation coefficient below 0.6. In contrast, commercial thin bricks have water absorption of 9–12%. Treated char-based stone veneer has water absorption of 5.3% and an average compressive strength of 19.2 MPa, maintains its structural integrity throughout 50 F-T cycles, and exhibits a negligible linear shrinkage of ap- proximately 0.01%. In contrast, commercial stone veneers have water absorption of 10–16%. These engineering properties meet the criteria as per ASTM standards C1088 and C1670 for thin brick and stone veneer, respectively. A techno-economic study was preliminarily conducted to examine the potential cost efficiency and cash flow in manufacturing these char-based building products. The manufacturing cost of USD 25.83 is lower than the average market price of 64.65 USD/sq. m. for thin bricks. The manufacturing cost of USD 32.65 is lower than the average market price of 129.17 USD/sq. m. for stone veneers. These comparisons present a compelling economic advantage for their commer- cialization. This comprehensive study has demonstrated the advantages of sustainable char-based stone veneers and thin bricks regarding engineering performance and economic benefits. Keywords: char product; masonry veneer; engineering properties; net present value; internal rate of return; sensitivity analysis 1. Introduction Thin bricks and stone veneers are common building products used primarily for deco- rating the external façade of a building or structure [1]. These products require less material for manufacturing and less labor for installation when compared to traditional bricks and natural stones. These inexpensive products bring the look of brick walls or natural stones to a building made from wood or other materials [2]. They have a maximum thickness of 44.5 mm for thin bricks [3] and 67 mm for stone veneers [4]. They are lightweight products and do not impose a substantial increase in dead loads for the buildings. In addition to aesthetic beauty, these products affect the temperature flow and humidity [5] between the atmosphere and the inside of the buildings. They act as an additional layer outside the main wall to provide insulation. This leads to a reduction in energy consumption [6] as the heat loss rate is slow compared to a building without an external cladding material. Conse- quently, there will be savings in cost and energy. Countries such as America, Canada, New Zealand, and England have experienced growing use of these products [6]. Some notable examples where such products are used include the University of Wyoming in America and the Electricity Museum in Portugal [6]. The lighter weight of these veneers compared Sustainability 2024, 16, 1854. https://doi.org/10.3390/su16051854 https://www.mdpi.com/journal/sustainability