The construction sector’s hidden role in deepening global inequalities

The con­struc­tion and oper­a­tion of build­ings con­sti­tute one of the main sec­tors emit­ting CO₂, the primary anthro­po­gen­ic green­house gas. In 2023, the sec­tor accounts for around 34% of energy-related CO₂ emis­sions (up to 37% when includ­ing emis­sions from build­ing mater­i­als), and 32% of glob­al energy demand¹. “Its share of glob­al green­house gas emis­sions is con­sid­er­able and can­not be ignored,” says José Lopez. Indeed, if we are to lim­it glob­al warm­ing to 1.5°C, the sec­tor accounts for 11% of the glob­al mit­ig­a­tion poten­tial by 2035.

And yet, this sec­tor is still a long way from achiev­ing its decar­bon­isa­tion tar­gets. Over the past two dec­ades, glob­al CO₂ emis­sions from build­ings have ris­en by 50%². Whilst emis­sions linked to build­ing use should have fallen by 28.1% between 2015 and 2023 to meet the sector’s decar­bon­isa­tion tar­gets, they have ris­en by 5.4%. None of the indic­at­ors, includ­ing energy intens­ity, the share of renew­ables, envir­on­ment­al cer­ti­fic­a­tions, invest­ment or policy pro­gress, is meet­ing its tar­gets. The reas­on? “The trend is driv­en by emer­ging and devel­op­ing eco­nom­ies, par­tic­u­larly in Asia,” notes José Lopez. Grow­ing energy demand is driv­en by Africa, Asia and the Pacific, and stud­ies show that this growth is set to con­tin­ue. As for developed eco­nom­ies, they have reduced emis­sions from res­id­en­tial build­ings and have man­aged to sta­bil­ise those from the non-res­id­en­tial sec­tor, accord­ing to the IPCC. Aus­tralia, Japan and New Zea­l­and are excep­tions, and the tra­ject­or­ies of these coun­tries as a whole vary significantly.

But cau­tion is needed: we must avoid simplist­ic argu­ments that point the fin­ger at emer­ging and devel­op­ing eco­nom­ies whilst prais­ing developed eco­nom­ies. “Cli­mate change is an indic­at­or of inequal­ity, and the build­ing sec­tor actu­ally illus­trates a double inequal­ity,” adds José Lopez. “The coun­tries that have his­tor­ic­ally emit­ted the most are not the ones build­ing the most today, and the pop­u­la­tions most in need of improved thermal com­fort are often those with the least means to access it sustainably.”

The IPCC’s 6th Syn­thes­is Report details the factors explain­ing why emis­sions from the sec­tor con­tin­ue to rise, focus­ing on the res­id­en­tial sec­tor, which is the primary com­pon­ent: pop­u­la­tion growth (28%), the increase in liv­ing space per cap­ita (and thus the lack of energy-sav­ing meas­ures, 52 per cent) and the rise in the car­bon intens­ity of the glob­al energy mix (16 per cent). How­ever, these factors vary greatly by region: for example, many people lack access to hous­ing, and the lack of energy-sav­ing meas­ures and the increase in liv­ing space per cap­ita there­fore affect only a por­tion of the glob­al pop­u­la­tion. Whilst pop­u­la­tion growth has a mod­er­ate impact on developed regions, it accounts for a large pro­por­tion of the rise in emis­sions in devel­op­ing regions. The oth­er factors, such as rising liv­ing stand­ards, a lack of energy-sav­ing meas­ures, and low uptake of renew­ables and energy effi­ciency, are also marked by sig­ni­fic­ant region­al disparities.

And how can we talk about the build­ing sec­tor without con­sid­er­ing the people involved? “Hous­ing is a right; there are colossal chal­lenges of social and geo­graph­ic­al equity in the face of dis­par­it­ies in access to hous­ing, health­care and edu­ca­tion,” agrees José Lopez. Whilst the grow­ing demand for energy is driv­en by Africa, Asia and the Pacific, their per cap­ita emis­sions remain well below those of developed regions. In 2019, glob­al aver­age emis­sions from the res­id­en­tial sec­tor stood at 0.85 tonnes of CO₂ per per­son per year. Emis­sions from the (res­id­en­tial) build­ing sec­tor exceed 1 tonne per per­son in sev­er­al regions (Europe and Euras­ia, North Amer­ica, East Asia, the Middle East and Aus­tralia, Japan and New Zea­l­and). Con­versely, all oth­er regions are below 0.3 tCO₂ per per­son (Africa, Lat­in Amer­ica and the Carib­bean, South-East and South Asia, and the Pacific)⁵.

These dis­par­it­ies high­light a cent­ral issue of cli­mate justice: the regions that con­trib­ute least to emis­sions are often those where con­struc­tion and adapt­a­tion needs are greatest. “Today, emer­ging and devel­op­ing eco­nom­ies want to build in the same way as Europe,” con­tin­ues José Lopez. “We need to strike a bal­ance and not simply con­verge towards the West­ern mod­el. This applies to devel­op­ing eco­nom­ies, but also to developed ones, which must make a sig­ni­fic­ant effort to reduce their energy con­sump­tion.” The aim is to achieve decent liv­ing stand­ards for the entire pop­u­la­tion, whilst adjust­ing stand­ards. In the sole car­bon-neut­ral scen­ario repor­ted by the IPCC, where stand­ards are the same across developed and emer­ging eco­nom­ies, the optim­al liv­ing space amounts to 20–40m² per per­son. “This also raises the ques­tion of the sector’s devel­op­ment mod­el: should we rep­lic­ate energy- and mater­i­al-intens­ive, high-car­bon mod­els, or devel­op mod­els adap­ted to loc­al con­texts that are more frugal and resi­li­ent?” points out José Lopez.

How­ever, pro­gress on build­ing and renov­a­tion codes and stand­ards has been slow, with around 20 new codes adop­ted in 2023, com­pared with just 3 in 2024. “Over­all, their level of imple­ment­a­tion remains lim­ited,” adds José Lopez. Accord­ing to the Inter­na­tion­al Energy Agency, around half of new build­ings con­struc­ted in emer­ging and devel­op­ing eco­nom­ies are not covered by energy per­form­ance reg­u­la­tions (com­pared with less than 30% for res­id­en­tial build­ings in developed coun­tries). How­ever, demo­graph­ic fore­casts point to glob­al pop­u­la­tion growth and a sig­ni­fic­ant rur­al exodus, with Africa and Asia account­ing for 90% of the lat­ter. “A doub­ling of built-up area is fore­cast by 2060, driv­en mainly by Africa,” says José Lopez. “Yet it is very dif­fi­cult to counter the stand­ard­isa­tion of con­struc­tion mater­i­als, such as con­crete, steel and glass, which mar­gin­al­ises oth­er sec­tors, such as earthen brick, which is par­tic­u­larly rel­ev­ant in Africa.”

Finally, whilst inequal­it­ies are glar­ingly obvi­ous in terms of respons­ib­il­ity and demo­graph­ic chal­lenges, a fur­ther one is added: the effects of cli­mate change. In Europe, for example, dir­ect CO₂ emis­sions from the build­ing sec­tor fell in 2022 thanks to mild winter tem­per­at­ures⁶. Con­versely, the rise in extreme weath­er events such as heat­waves poses a par­tic­u­lar chal­lenge in the Asia-Pacific region. “These events, com­bined with poor-qual­ity con­struc­tion and rising liv­ing stand­ards, are caus­ing a surge in the use of air con­di­tion­ing,” com­ments José Lopez. Two-thirds of the world’s pop­u­la­tion lives in hot cli­mates, so access to cool­ing solu­tions is becom­ing a pub­lic health issue. But its expan­sion can increase emis­sions and strain on elec­tri­city grids, and we expect energy con­sump­tion in the build­ing sec­tor for air con­di­tion­ing to triple by 2050!

The levers for decar­bon­ising the sec­tor are well known, as the IPCC explains: mod­er­a­tion (occupy­ing all exist­ing build­ings, shar­ing hous­ing, adjust­ing size to chan­ging needs, etc.), energy effi­ciency and redu­cing the car­bon intens­ity of energy. Imple­ment­ing these meas­ures would be effect­ive: the mit­ig­a­tion poten­tial amounts to 8.2 bil­lion tonnes of CO₂ by 2050. It is highest in emer­ging and devel­op­ing eco­nom­ies (5.4 bil­lion tCO₂) des­pite these coun­tries cur­rently emit­ting less CO₂ in this sec­tor and stands at 2.7 bil­lion tCO₂ for developed eco­nom­ies. “Real­ising this mit­ig­a­tion poten­tial poses a major social chal­lenge: the poorest house­holds often live in the least energy-effi­cient homes. Without appro­pri­ate sup­port­ing meas­ures, the build­ing sec­tor trans­ition there­fore risks exacer­bat­ing inequal­it­ies,” con­cludes José Lopez.

Anaïs Marechal