# Measuring Carbon in Cities and Their Buildings through Reverse Engineering of Life Cycle Assessment
## 5 Conclusions  
It has been demonstrated through this paper that percentage and average calculation methods for LCA target, predicted or optimized (through a linear regression model), indicators values can be useful in finding excellent benchmarking in carbon emissions reduction, for measurements and sustainable design in cities. Possible future work includes the simulation of different cases for percentage calculation for impact estimations of a design in a city context. Minor findings are the following: the difficulty in using the chosen materials database for LCA calculation, the consideration of the loss of forests in the most of low carbon design solutions, and consequently of its carbon reduction removal; unconventional instead of conventional sustainable design solutions as the best asset for reduction of carbon emissions; and the recommendation for coherence of the use of real in situ measurements of carbon emissions. The model used in this paper was carried out in 2021 and 2022. However, the GWP results, and the model are the same for the updated Database and LCA tool in 2022 and 2023. Adding more data to the model for better accuracy in measurements, seemed the best option. This paper shows this is unnecessary; thus, as [PERSON] explained [67], the reasons for a RE application to a database are to comprehend the relation between the objects involved and to build upon it. Afterward, the method allows for redesigning the database structure, expanding the database with new database objects, and creating the system documentation. One of the hypotheses formulated relates to a Target in Carbon reduction of 11% when 25% of houses with a GWP\({}^{\text{T}}\) of around \(-30.000\) CO\({}_{2}\)eq or lower (\(-165\) CO\({}_{2}\)eq/m\({}^{2}\)). With reference to carbon emissions reduction recommendations and regulations in Denmark, this paper presents stricter target values than those. Since conventional values are around 86,580 CO\({}_{2}\)eq [65] in some recent studies; in regulations, limit values are around 110,000 CO\({}_{2}\)eq and very ambitious target values are around 74,000 CO\({}_{2}\)eq. In this paper, the reductions are considered from 92,530 CO\({}_{2}\)eq or from 83,120 or from 84,615 CO\({}_{2}\)eq average, which can be considered conventional housing in some studies, although can be considered low carbon housing in several actual regulations. The value 493 of GHG Emis. (Emission intensity on building level, CO\({}_{2}\)eq/m\({}^{2}\)), of the recent document these Table percentages is based on [10], and it was obtained using statistical data on construction cost per square meter. Further applications of the method should exploit its advantages which among others are its characteristics of a global method applicable in different countries and scenarios, the standardization of the method for different typologies and regulations, its interoperability with other sustainability assessment and design tools, its previous automation studies, flexibility and adaptability to be an easy guide for designers, normalization possibilities [68], and other methods compatibility [69]. To sum it up, this paper's RE has been proven to help measurements to identify unconventional solutions in materials and circular systems for buildings design, useful for partial design estimation based on total design, also for further analysis for very crucial indicators related, design for itself can lead to reaching European Targets for resilience, health and biodiversity would be protected first, \"clean energy\" used in a building in the use stage of the building has not as much influence as circular-low impact-healthy construction solutions in fast pollution reduction in a city context. However, this method's main merits are its capability for standardization, globalization, interoperability, automation, certification, economic benefits, and most importantly, for guiding designers.