Typically, buildings are predominantly influenced by their exteriors, wherein the heat gain/loss through the envelope surpasses the internal heat generation (Givoni 1998). The building envelope's significance lies in its potential to contribute up to 73% of the total heat gain/loss (DOE 2004). Therefore, energy-efficient building envelopes can mitigate reliance on fossil fuels and minimize environmental pollution. This paper investigates the thermal performance of a hotel's envelope in Matheran concerning energy efficiency. As Matheran's tourism revolves around its pristine environment, preserving its quality necessitates environmentally sustainable development and operations. Consequently, the adoption of green measures becomes crucial, particularly in existing hotel envelopes, as new constructions are prohibited in Matheran. To achieve this, understanding heat gain parameters based on the material characteristics of different envelopes becomes paramount. The primary objective is to conduct a comparative analysis of two distinct building envelopes within a Matheran hotel: the traditional load-bearing Laterite stone construction and the contemporary RCC framed brick structure. The aim is to identify the most energy-efficient option based on their potential for energy savings. Both envelopes undergo thermal performance simulation modeling using ECOTECT and eQUEST software. The analysis of the simulations reveals that the traditional construction's building envelope exhibits superior thermal performance, thus rendering it more energy-efficient. Furthermore, the study proposes enhancing the energy efficiency of the contemporary envelope by modifying its roof, wall, and fenestration properties. The proposed modifications are then subjected to simulation to determine their impact on thermal performance and potential for improved energy efficiency.