| MEANING | DEFINITION | |
|---|---|---|
| BRE | Building and real estate | The sum of all activities, supply chains, processes and stakeholders in the whole life-cycle (WLC) of buildings, property and real estate only, not including civil infrastructure |
| DEs | Decarbonisation efforts | An overarching term referring to the goals, initiatives, strategies and actions (e.g. carbon budget, limit values, pledges, pathways) aimed at reducing carbon dioxide (CO2) and/or other greenhouse gas (GHG) emissions |
| GHGs | Greenhouse gases | The Intergovernmental Panel on Climate Change (IPCC) describes GHGs as the gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of radiation emitted by the Earth’s surface, by the atmosphere itself and by clouds. This property causes the greenhouse effect. Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3) are the primary GHGs in the atmosphere. Human-made GHGs include sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs), chlorofluorocarbons (CFCs) and perfluorocarbons (PFCs) (IPCC 2023) |
| SLR | Systematic literature review | A methodical comprehensive review of the existing literature |
| WLC | Whole life-cycle | All processes related to the planning, design, construction, operation, maintenance, refurbishment and deconstruction of buildings, including end-of-life processes |
Figure 1
Systematic literature review (SLR) search and results.
Table 1
Overview of the analysed factors, characteristics and evaluation factors in points.
| FACTOR | CHARACTERISTIC | POINTS | FACTOR | CHARACTERISTIC | POINTS |
|---|---|---|---|---|---|
| Temperature limit | 1.5°C | 1.10 | Decarbonisation goal | Net zero carbon | 1.10 |
| 2.0°C | 1.00 | Net zero emissions | 1.05 | ||
| None | 0.00 | Carbon neutrality | 1.00 | ||
| Main indicator | GHG emissions | 1.00 | Decarbonisation | 0.92 | |
| CO2 emissions only | 0.50 | Zero carbon | 0.83 | ||
| Other, non-GHG | 0.00 | Zero emissions | 0.75 | ||
| Life-cycle scope | WLC | 1.00 | Near zero emissions | 0.67 | |
| Embodied onlya | 0.67 | Low carbon | 0.58 | ||
| Operational only | 0.33 | Low emissions | 0.50 | ||
| Other | 0.00 | Net zero energy | 0.42 | ||
| Target year | 2020–25 | 1.10 | Zero energy | 0.33 | |
| 2030 | 1.08 | Near zero energy | 0.25 | ||
| 2035 | 1.06 | 2000 Watt Society | 0.17 | ||
| 2040 | 1.04 | Low energy | 0.08 | ||
| 2045 | 1.02 | None | 0.00 | ||
| 2050 | 1.00 | Scale of assessment | Whole BRE | 1.00 | |
| 2060 | 0.66 | Building stockb | 0.67 | ||
| 2100 | 0.33 | Individual building | 0.33 | ||
| None | 0.00 | Other | 0.00 |
[i] Note: aAlthough not further disaggregated, this can refer to up-front, use-phase or end-of-life embodied emissions (Caballero-Güereca et al. 2025).
bThe building typologies considered in the building stocks vary (sometimes only residential or educational buildings are considered).
BRE = building and real estate; GHG = greenhouse gas; WLC = whole life-cycle.
Note: aIn the literature, terms to describe the energy type (primary, final, renewable, non-renewable, etc.) might be used, but for this paper, they were grouped in the same category.
BRE = building and real estate;
GHG = greenhouse gas;
WLC = whole life-cycle.
Figure 2
Temporal distribution of documents by document type.
Note: Dot size is proportional to document count; maximum = 23.
Figure 3
Temporal and geographical distribution of documents considering the life-cycle scope.
Note: Dot size is proportional to document count; maximum = 14.
Table 2
Typologies of the terms and definitions for goals used in the literature.
| TERM | DEFINITION (AS USED IN THE LITERATURE) | REPRESENTATIVE DOCUMENTS |
|---|---|---|
| Low energy | Focuses on reducing operational energy demand in new buildings or retrofits | Blengini & Di Carlo (2010); European Commission (2019); Grove-Smith et al. (2018); Mata et al. (2020) |
| 2000 Watt Society | Swiss concept aiming to limit per capita primary energy demand to 2000 W by 2050 and transitioning to a fully renewable energy supply | Aumann (2012); Heeren et al. (2012); Purtik et al. (2016); Scarinci et al. (2017); Schulz et al. (2008) |
| Near-zero energya | Mostly used at the building level, it refers to the improving energy performance to minimise operational energy demand. Does not necessarily include renewable energy production | Attia et al. (2017); Besser & Vogdt (2017); D’Agostino (2015); D’Agostino et al. (2017); D’Agostino & Mazzarella (2019); Gauch et al. (2023); Kuramochi et al. (2018); Liu et al. (2019a, 2019b); Magrini et al. (2020); Mata et al. (2018); Oh et al. (2017); Patiño-Cambeiro et al. (2016); Reda & Fatima (2019); Santos-Herrero et al. (2018); Szalay et al. (2022) |
| Zero energy | Mostly used at the building level, it refers to the (currently outdated) concept of offsetting grid energy demand with on-site renewable energy generation and use across a time period (typically annually) | Belussi et al. (2019); Cao et al. (2016); Kylili & Fokaides (2015); Marszal et al. (2011); Mytafides et al. (2017); Saheb et al. (2018); Staniūnas et al. (2013) |
| Net zero energy | Used at building and building stock level, it refers to the balance between grid energy demand and renewable energy supply through renewable energy production and exports across a time period (typically annually) | Asdrubali et al. (2018); Feng et al. (2019); Harkouss et al. (2018); Kapoor et al. (2011); Kolokotsa et al. (2011); Korpal (2020); Liu et al. (2019b); Pless et al. (2014); Pless & Torcellini (2010); Sartori et al. (2012); Torcellini et al. (2015); Ürge-Vorsatz et al. (2020); Wells et al. (2018) |
| Low emissions | Reduction of CO2 or GHG emissions (operational and/or embodied) at any scale | Langevin et al. (2019); Oshiro et al. (2020); Scherz et al. (2023) |
| Low carbon | Broad term referring to the reduction of operational and/or embodied GHG emissions (‘carbon’ is commonly used in the literature as a proxy for all GHGs) at any scale | Akbarnezhad & Xiao (2017); Alwan & Jones (2014); Chandrakumar et al. (2019, 2020); Cui et al. (2019); Du et al. (2024); European Commission (2019); Fajardy & MacDowell (2020); Freis et al. (2016); Galimshina et al. (2024); Government of Canada (2016); Hafner & Özdemir (2022); Häkkinen et al. (2015); Koo et al. (2015); Kuittinen & Häkkinen (2020); Lützkendorf & Balouktsi (2022); Mata et al. (2020); Mota & Heras (2018); Nishioka (2016); Pomponi & Moncaster (2016); Resch et al. (2022); Satola et al. (2021); Shahmohammadi et al. (2024); UKGBC (2014); Wang et al. (2018); Wright et al. (2014); Yang et al. (2021) |
| Near zero emissions | Operational and/or embodied emissions at any scale are decreased to the minimum unavoidable ‘residuals’, but no negative emissions or offsets are considered | Chaudry et al. (2015); Georges et al. (2015); Knobloch et al. (2019); Ruparathna et al. (2017) |
| Zero emissions/zero carbon | Complete elimination of emissions without considering negative emissions. This term generally implies an incomplete scope (e.g. considering only operational direct emissions of buildings) | Chandrakumar et al. (2019, 2020); European Commission (2019); Kristjansdottir et al. (2018); Mata et al. (2020); Röck et al. (2020); Shahmohammadi et al. (2024); Stephan & Stephan (2020); Xing et al. (2011) |
| Decarbonisation | An overarching term describing the process to phase out the use of fossil fuels and eliminate the GHG emissions of a building stock or the BRE sector. Since it is a generic term, it is not linked to specific scopes or scales | Bataille et al. (2016); Broer et al. (2021); Camarasa et al. (2022); Hill et al. (2019); IGBC (2022b); Korpal (2020); Mota & Heras (2018); Ouria & de Almeida (2021); Shahmohammadi et al. (2024); Sulzer et al. (2020); Szalay et al. (2022); Toth et al. (2022); World GBC (2019); Xia-Bauer et al. (2024) |
| Carbon neutrality | A broad term commonly used at the operational level to describe a fully renewable energy infrastructure and at the embodied level to describe the use of bio-based products in buildings/stocks or the BRE sector which (temporarily) store carbon during its life-cycle, releasing it at the end of life (also known as the –1/1 approach) | Braune et al. (2019); Ferreira et al. (2020); Hu et al. (2022); Huo et al. (2021); Roca-Puigròs et al. (2020); Wheeler (2017); Zou et al. (2023) |
| Net zero emissions | The WLC reduction of emissions to the residuals and followed by an offset through using negative emissions through a net balance accounting (e.g. credits from avoiding emissions beyond the system boundary), the purchase of CO2 certificates or the use of negative-emission technologies (Lützkendorf & Frischknecht 2020). The balancing can be done across various time periods | Alaux et al. (2023); Allen et al. (2022); Balouktsi & Lützkendorf (2022); Bullen et al. (2021); Dai et al. (2024); Frischknecht et al. (2019, 2020); Fyson et al. (2023); Horup et al. (2024); Im & Kwon (2022); Lützkendorf & Balouktsi (2022); Lützkendorf & Frischknecht (2020); Maierhofer et al. (2024); Pórólfsdóttir et al. (2023); Priore et al. (2021, 2023); Robiou du Pont et al. (2025); Satola et al. (2021); Schmidt et al. (2020); Science Based Targets (2024); Shimoda et al. (2021); Stephan & Stephan (2020); Sugsaisakon & Kittipongvises (2024); World GBC (2019); Zhang et al. (2024) |
| Net zero carbon | This term is interchangeably used with net zero emissions. However, it also means that GHG emissions have first been lowered to a minimum during the WLC, and then the residual emissions are offset by negative-emission technologies. The balancing can be done across various time periods. The term is common in recent reports and policies, but not always explicitly defined to include embodied emissions. When termed as net zero ‘whole life carbon’, it includes both embodied and operational emissions. However, there is a lack of transparency in the granularity of materials and components considered, and completeness of life-cycle phases. In most of the literature found, it accounts not only for CO2 emissions but also for other GHG emissions. Most of the grey literature added through snowballing aligns with this goal | Amaripadath et al. (2024); Balouktsi et al. (2024); BPIE (2023a); Broer et al. (2021); CCC (2019); Cerasoli & Porporato (2023); EAC (2022); Global ABC (2024); Habert et al. (2020); He & Prasad (2022); Hill et al. (2019); Horup et al. (2023); Hu (2022); IEA (2022, 2023a); IGBC (2022a, 2022b); IPA (2021); JH Sustainability et al. (2020); Kruit et al. (2020); Kuriakose et al. (2022); LETI (2020, 2023); Maierhofer et al. (2022); Marin et al. (2024); Mitchell-Larson et al. (2023); Nugent et al. (2023); O’Dwyer et al. (2023); Oghazi et al. (2023); O’Hegarty et al. (2022); Ohene et al. (2023); Passivhaus Trust (2019); Prasad et al. (2021); Priore et al. (2022, 2023); Scherz et al. (2020); Schrembi (2022); Shabha et al. (2023); Sharmina et al. (2023); Sinclair (2020); Steininger et al. (2020); Szalay et al. (2022); Tirelli & Besana (2023); Toth & Volt (2021); Toth et al. (2022); Tozan et al. (2024); UKGBC (2019, 2021a, 2021b, 2024); Ürge-Vorsatz et al. (2020); Velten et al. (2022); WSP (2021); Wu et al. (2022); Xia-Bauer et al. (2024) |
[i] Note: aIn the literature, terms to describe the energy type (primary, final, renewable, non-renewable, etc.) might be used, but for this paper, they were grouped in the same category.
BRE = building and real estate; GHG = greenhouse gas; WLC = whole life-cycle.
Figure 4
Temporal distribution of decarbonization targets and goals.
Note: Dot size is proportional to document count; maximum = 16.
Figure 5
Assessment scale considered in the screened documents.
Note: Dot size is proportional to document count; maximum = 13.
Figure 6
Parallel coordinates plot showing how combinations of key analytical factors in the reviewed literature relate to alignment with current decarbonisation needs.
Note: Each line represents a single document, coloured according to its overall rating.