Published 15 June 2026^{Publication date of this guide, aligned with the page's schema.org markup (datePublished and dateModified: 2026-06-15).Source to be established — unverified figure} 21 min read · the essentials in 2 min LCI Geneva SIA 390/1 · 2032 · KBOB Updated June 2026

Embodied energy in construction

For decades, a building's energy performance was measured solely by its operational consumption. Today, the energy embodied in materials — embodied energy — accounts for about a quarter of the primary energy of a new low-energy building, and roughly half the carbon balance of a high-performance building heated from renewables^{SFOE/SwissEnergy, "Embodied energy in new buildings" (06.2017), p. 6: 42.0 kWh/m²·yr of embodied energy out of 158.9 kWh/m²·yr in total for a low-consumption apartment building, i.e. about 26%.Office fédéral de l'énergie (OFEN) / SuisseEnergie — L'énergie grise dans les nouveaux bâtiments — Guide pour les professionnels2017-06 · accessed 2026-09-04}. This has become a central issue, and Geneva's legal framework now reflects it directly.

In short

Two indicators sit side by side here. Only one is enforceable in Geneva: carbon, in kg CO₂-eq/m²·yr. The MJ/m²·yr of embodied energy serve for comparison, not for proving compliance.
The limit values are set by the RECMC: 5 kg CO₂-eq/m²·yr for renovation, 11.3 for new housing, 12.6 for offices, schools, retail and restaurants.
The timetable: mandatory from 2027 for cantonal buildings, a low-carbon concept for everyone from 2029, limit values enforceable on everyone from 2034.
Embodied energy accounts for about a quarter of the primary energy of a high-performance new building, and roughly half its carbon balance. The better the building, the larger that share.
Biogenic carbon in timber is reported separately and never deducted: timber's advantage is real but moderate — 6 against 8 kg CO₂-eq/m²·yr versus heavyweight construction.
Three levers decide the outcome: structure (timber or concrete), insulation (bio-based or synthetic) and compactness. They are settled at preliminary design — after that, one only records.

In this guide

What is embodied energy? The building life cycle The footprint of materials LCI art. 117 & 118 SIA 2032, KBOB and calculation tools Reduction strategies Labels and embodied energy Key questions

01 — Definition

What is embodied energy?

Embodied energy (or incorporated energy) refers to all the energy required to produce a building: raw material extraction, industrial processing, transport, on-site installation, maintenance, replacement over the building's life, then demolition and end-of-life treatment.

It is expressed in non-renewable primary energy — historically in MJ/m² of energy reference area (SRE), or in kWh/m²·an annualised over the building's standard service life (60 years per SIA 2032 technical guideline^{Minergie, embodied energy calculation method (2021): building service life of 60 years, component amortisation periods taken from the SIA 2032 technical guideline.Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3)2021-03-31 · accessed 2026-08-20}). But the indicator now used by Geneva's legal framework is not energy: it is the embodied carbon, i.e. the balance of greenhouse gas emissions expressed in kg CO₂-eq/m²·an.

A very well-insulated building consumes little operational energy — but if its walls are heavily reinforced concrete with synthetic foam insulation, its embodied energy can cancel out several years of operational savings.

~25 %

of the total primary energy of a new low-energy building (SFOE: 42 of 159 kWh/m²·an)

60 years

reference service life per SIA 2032 for the annualised calculation

~6–12

kg CO₂-eq/m²·an: embodied carbon range for construction (new build)^{RECMC (rsGE L 5 05.05, 15.10.2025): 11.3 kg CO₂-eq/m²/yr for new housing and 12.6 for administration, schools, retail and restaurants; ecobau places new build between 5 and 10.5.République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.052025-10-15 · accessed 2026-08-20} — Geneva regulatory indicator

~90–150

MJ/m²·an: embodied energy range (primary energy) for a standard new building^{Minergie-ECO, p. 11, new-build limit values (Wohnen MFH): GW1 25.0 and GW2 36.1 kWh/m²EBF·yr, i.e. 90–130 MJ/m²·yr; SFOE guide 8719, p. 6, gives embodied energy as 42 kWh/m²·yr (151 MJ).Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3)2021-03-31 · accessed 2026-09-04}

Two indicators not to be confused Embodied energy measures a quantity of non-renewable primary energy (kWh or MJ/m²·an). Embodied carbon measures greenhouse gas emissions (kg CO₂-eq/m²·an). The two are related but distinct: a material can be energy-intensive without being very carbon-intensive, and vice versa. The decisive point in Geneva: the legal framework (LCI art. 117-118) regulates carbon — so compliance is measured in kg CO₂-eq/m²·an, not in MJ.

Embodied energy vs operational energy Operational energy (heating, domestic hot water, ventilation, lighting) is the energy consumed during the building's life — this is what the HPE, Minergie® or Passivhaus labels measure. Embodied energy, by contrast, is "spent" even before the building is occupied. The more energy-efficient a building is in operation, the greater the relative share of embodied energy in its overall balance: the two now go hand in hand.

02 — Life cycle assessment

The building life cycle

Life Cycle Assessment (LCA) — or Analyse du Cycle de Vie (ACV) — is the standardised method for quantifying a building's environmental impact from "quarry to landfill". In Switzerland, the technical guideline SIA 2032 (life cycle inventory method) and the European standard EN 15978 structure the LCA into four main modules.

Production & construction

A1–A3: raw material extraction, product manufacturing
A4: transport to site
A5: installation and construction waste

Use

B1: impacts during use
B2–B5: maintenance, repair, replacement
B6–B7: operational energy and water use

End of life

C1: deconstruction / demolition
C2: waste transport
C3–C4: waste processing, disposal

Beyond the system boundary

Net benefits: material recycling, energy recovery, reuse. Biogenic carbon — the CO₂ the tree took from the air as it grew and that the wood keeps in store — is not counted in the emissions balance under SIA 390/1 and KBOB: it is reported separately. It is therefore not a deductible emissions credit.

In practice, Geneva's regulatory calculation relies on modules A1–A5 (material manufacturing, transport and installation) and B4 (replacements over the service life), which make up most of the embodied energy for a well-designed new building. Modules C and D are included in comprehensive approaches: SNBS, the Swiss Sustainable Building Standard, and DGNB, the German certification system for sustainable buildings. Both are whole-sustainability frameworks, not energy labels.

Component service life: a key factor Embodied energy includes replacements over the service life (module B4). Under the amortisation periods of technical bulletin SIA 2032, the structure (excavation, load-bearing frame) counts 60 years^{Corrigendum C1:2013 to SIA 2032:2010, annex C: 60 years for excavation and structure (B, C), 30 to 40 years for the envelope (E, F), 20 to 30 years for building services (D) — 40 years for borehole probes alone.Société suisse des ingénieurs et des architectes (SIA) — Cahier technique SIA 2032 « L'énergie grise des bâtiments » — correctif C1:2013 à l'édition 2010, annexe C (durées d'amortissement)2013 · accessed 2026-09-04}, the envelope (façades, roof, external finishes) 30 to 40 years and building services (mechanical ventilation, heat pump) 20 to 30 years. Insulation or a finish replaced twice over 60 years doubles its embodied energy impact — hence the importance of the intrinsic durability of the materials chosen.

03 — The footprint of materials

Not all materials are equal

Embodied energy varies considerably depending on the material. The Swiss database KBOB (Koordinationskonferenz der Bau- und Liegenschaftsorgane der öffentlichen Bauherren)^{Official name on kbob.admin.ch: Koordinationskonferenz der Bau- und Liegenschaftsorgane der öffentlichen Bauherren — the Swiss public-sector building owners' coordination conference.Confédération suisse — kbob.admin.ch — Conférence de coordination des services de la construction et des immeubles des maîtres d'ouvrage publics KBOBaccessed 2026-08-20} publishes the reference values used in all regulatory calculations in Switzerland. The chart below compares the embodied energy of typical constructions per m² of energy reference area (SRE)^{The RECMC uses neither "surface de référence énergétique" nor "SRE": its annex states limit values in kg CO2 eq./m2/an and refers the calculation to standard SIA 390/1:2025 (art. 3 para. 2, art. 5 para. 2).République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.052025-10-15 · accessed 2026-09-04}.

Standard reinforced concrete
Structure + slabs + concrete façade

~9,5 kg CO₂-eq/m²·an

Masonry + synthetic insulation
PIR / EPS / PUR

~9 kg CO₂-eq/m²·an

Concrete + mineral insulation
Rock wool / glass wool

~8 kg CO₂-eq/m²·an

Timber structure + mineral insulation
CLT or timber frame

~6,5 kg CO₂-eq/m²·an

Solid wood + bio-based insulation
Hemp, cellulose, wood fibre

~5,5 kg CO₂-eq/m²·an^{ecobau, "Bâtiments à faibles émissions de gaz à effet de serre", June 2025, V1-0, table 4 p. 22 (kg CO₂-eq/m²SRE·yr): new build, "moyenne" column, timber 6 against 8 massive; "bas" column, timber 5 to 5.5.ecobau — Bâtiments à faibles émissions de gaz à effet de serre — guide pour les maîtres d'ouvrages (état juin 2025, V1-0)2025-06 · accessed 2026-09-04}

Wood + bio-based + partial reuse
Reclaimed materials, CO₂ storage

≤ 4,5 kg CO₂-eq/m²·an

Construction embodied carbon (kg CO₂-eq/m²·an): the indicator that is enforceable in Geneva. In embodied energy, the same series runs from around 150 MJ/m²·an for standard reinforced concrete^{Series calibrated on the Minergie-ECO new-build limit values (p. 11: 25.0 and 36.1 kWh/m²EBF·yr, i.e. 90–130 MJ/m²·yr) and on the 42 kWh/m²·yr (151 MJ) of SFOE guide 8719, p. 6.Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3)2021-03-31 · accessed 2026-09-04} down to under 80 MJ/m²·an on the last row. Indicative values, annualised over 60 years, modules A1–A5 + B4, per m² SRE.

According to the SFOE, the structural shell accounts for about one third of embodied energy^{SFOE, guide to embodied energy in new buildings, p. 12: "about one third" for the structural shell (group C), "one fifth each" for interior fit-out (G) and services (D); C, D and G offer the greatest potential.Office fédéral de l'énergie (OFEN) / SuisseEnergie — L'énergie grise dans les nouveaux bâtiments — Guide pour les professionnelsaccessed 2026-09-04}, with building services and interior fit-out about one fifth each.

Wood: a carbon advantage 1 m³ of solid wood stores around 900 kg of CO₂^{Lignum: "One cubic metre of wood stores the carbon of about one tonne of CO₂." The timber/concrete gap at building scale comes from ecobau (new housing: 6 against 8 kg).Lignum — Économie suisse du bois — Bois et CO2accessed 2026-08-20} — the carbon of about one tonne, per Lignum. At building scale the timber/concrete gap stays moderate: 6 against 8 kg CO₂-eq/m²·an for new housing, i.e. 15 to 25 % less (ecobau). In module D, wood at end of life can be recovered for energy, returning part of the primary energy.

Steel: high performance, high energy Steel is very strong for its mass — but its production energy is high, around 20 GJ/t for the blast-furnace route (world average)^{KBOB, life cycle inventory data for construction: 0.682 kg CO₂-eq/kg for reinforcing steel and 0.734 for structural steel; ~20 GJ/t is the world average of the blast-furnace route.KBOB / eco-bau / IPB — Ökobilanzdaten im Baubereich / Données des écobilans dans la construction 2009/1:20162016-09 · accessed 2026-08-20}. KBOB gives 0.68 kg CO₂-eq/kg for reinforcing steel and 0.73 kg CO₂-eq/kg for structural steel. Used in composite steel-concrete structures it markedly increases structural embodied energy; the electric route (arc furnace, recycled steel) clearly reduces this impact.

04 — Geneva's legal framework

LCI art. 117 & 118: what the law requires

The canton of Geneva has embedded, in its loi sur les constructions et les installations diverses (Buildings and Miscellaneous Installations Act, LCI, of 14 April 1988, rsGE L 5 05)^{Official title cited in the RECMC preamble: "loi sur les constructions et les installations diverses, du 14 avril 1988" (LCI, rsGE L 5 05), art. 117 and 118.République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.052025-10-15 · accessed 2026-08-20}, requirements that go beyond mere operational energy performance. Articles 117 and 118 form a complementary pair: one sets the rule for material selection, the other the method for measuring their carbon impact.

LCI · Art. 117 Embodied carbon of materials — priority to reuse

Article 117 requires limiting the embodied carbon of construction materials, establishing a clear hierarchy:

Priority to reused materials^{LCI art. 117 (from PL 12869): new builds and major renovations must minimise the carbon footprint, favouring reuse first, then recycled or low-carbon materials.MLL Legal — MLL News Portal — L'empreinte carbone au cœur du droit genevois de la constructionaccessed 2026-08-20} — components recovered and reused
Failing that, use of recycled materials
Encouragement of low-embodied-energy materials (wood, bio-based, geo-sourced, local materials)

This is the legal framework for the "zero waste" approach and reuse on Geneva construction sites — the one applied from 2022 on the Carouge 87 renovation, presented as French-speaking Switzerland's first zero-waste site^{Chantiers Magazine (28.11.2022): works started in 2022 and the site is presented as the first "zero waste" project in French-speaking Switzerland.Chantiers Magazine — Zéro déchet — Rénovation durable au cœur de Genève2022-11-28 · accessed 2026-08-20}.

LCI · Art. 118 Calculating embodied carbon — full life cycle

Article 118 defines how this footprint is measured: a balance of greenhouse gas emissions over the entire life cycle of the materials used, expressed in kg CO₂-eq/m²·an — material manufacturing, installation, operation, deconstruction. In practice:

The reference standard is SIA 390/1 "The Climate Path" (which replaced the SIA 2040 technical guideline); it sets limit and target emission values
The calculation is based first and foremost on the KBOB database (RECMC art. 5); the SIA 2032 technical guideline remains the life cycle inventory specification used in practice
The limit values are set by the regulation on the carbon footprint of construction materials (RECMC, rsGE L 5 05.05, of 15 October 2025, in force since 22 October 2025)^{RECMC adopted 15.10.2025, in force 22.10.2025: renovation 5 kg CO₂-eq/m²/yr; new build 11.3 (housing) and 12.6 (administration, schools, retail, restaurants), based on SIA 390/1:2025.République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.052025-10-15 · accessed 2026-08-20}: 5 kg CO₂-eq/m²/yr for renovation, 11.3 for new housing and 12.6 for administration, schools, retail and restaurants — binding from 2027 for State buildings, low-carbon concept from 2029, limit values for all from 2034^{RECMC (rsGE L 5 05.05): low-carbon concept mandatory from 2029, limit values applying to State buildings from 2027 and to all projects from 2034.République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.052025-10-15 · accessed 2026-08-20}

The calculation method by category The carbon balance is not calculated material by material: the building is broken down into categories — foundations, load-bearing structure, envelope, interior fit-out, technical installations — each assessed using KBOB values and then summed. It is this breakdown that makes the approach practicable and comparable from one project to another. It is set out in full, together with its application to a real site, in the reuse dossier.

And what about the HPE / THPE levels? Contrary to a common misconception, the HPE and THPE levels are not defined by these articles of the LCI: they fall under the règlement d'application de la loi sur l'énergie (implementing regulation of the Geneva Energy Act, REn, art. 12B and 12C — rsGE L 2 30.01)^{The REn is the implementing regulation of the Energy Act and carries the number rsGE L 2 30.01; its art. 12B (HPE) and 12C (THPE) define the Geneva standards.République et canton de Genève — Recueil systématique (silgeneve.ch) — rsGE L 2 30.01 — Règlement d'application de la loi sur l'énergie (REn), du 31 août 19881988-08-31 · accessed 2026-08-20} and concern the energy performance of operation. See the comparative guide to labels.

Weighing of interests: LEn (L 2 30) ↔ LCI — towards the primacy of carbon? The two frameworks can come into tension. Aiming for a THPE level under the LEn drives down operational energy — more insulation, higher-performance glazing, more building services. Yet each of these additions carries a cost in embodied energy and embodied carbon, precisely what the LCI aims to limit. Beyond a certain point, the operational gain can be partly cancelled out by the additional construction carbon. Professional practice tends to consider that carbon logic (LCI) should take precedence over energy logic alone (LEn) when trade-offs arise — an orientation, however, that is not yet officially settled. Pending a formal framework, best practice is to optimise jointly both balances from the design stage, rather than maximising one at the expense of the other.

05 — Calculation tools

SIA 2032, KBOB and software

Calculating embodied energy rests on three complementary pillars: a methodological technical guideline (SIA 2032), a database of material values (KBOB), and software tools that combine the two.

Swiss standard

SIA 390/1 — The Climate Path

Standard "The Climate Path – Greenhouse gas balance over the life cycle of buildings" (2025 edition, replacing the SIA 2040 technical guideline)^{Espazium: standard SIA 390/1 "The Climate Path – Greenhouse gas balance over the life cycle of buildings" was published on 1 February 2025 and replaces the SIA 2040 technical guideline.Espazium — Les éditions pour la culture du bâti — La SIA pose de nouveaux jalons pour une construction respectueuse du climat2025 · accessed 2026-09-04}. Sets limit and target values in kg CO₂-eq/m²·an. This is the standard referenced by Geneva's LCI (art. 118).

Swiss technical guideline

SIA 2032 — Embodied Energy of Buildings

Technical guideline describing the life cycle inventory method: LCA modules to include, standard component service lives, presentation rules. It is the "calculation specification" used in practice; Geneva's RECMC, for its part, refers only to standard SIA 390/1:2025 and, first and foremost, to the KBOB database.

Geneva cantonal tool

Bilan carbone chantier (BCC, Construction Site Carbon Balance)

Platform developed by the State of Geneva, SIG and SSE (formerly B2CB, renewed in 2025)^{SSE Geneva, contact point of 09.10.2025: the BCC platform was "lancée en 2025 pour remplacer l'ancien outil Bilan Carbone Chantier et Bâtiment (B2CB), développé en 2014 par la SSE Genève" with the State and SIG.Société Suisse des Entrepreneurs — Section de Genève — Point contact « Nouvelle plateforme bilan carbone chantier (BCC) »2025-10-09 · accessed 2026-09-04}. Calculates construction-site GHG emissions by work package (building, civil engineering, networks). Free and open to professionals — it is a calculation aid: compliance under the RECMC is established using standard SIA 390/1:2025^{RECMC art. 5 and 6: the calculation is based first and foremost on the KBOB database and on standard SIA 390/1:2025, by work domain; no software is prescribed.République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.052025-10-15 · accessed 2026-08-20} and KBOB data, no software being prescribed.

Swiss database

KBOB — Life Cycle Inventory Data

Database maintained by Swiss public sector building owners. Provides values for non-renewable primary energy (EPNR), total embodied energy and global warming potential (GWP, in kg CO₂-eq) — the carbon indicator, which is not the same thing as primary energy for all common construction materials.

On the software side, none is prescribed: eco2soft (baubook, Austria) suits standard projects, One Click LCA complex projects and multi-standard certifications, Lesosai adds an embodied energy module to the regulatory thermal calculation — PHPP itself covers operation only. All rely on the ecoinvent database in the background; in Switzerland it is the KBOB values that count.

When to calculate? Embodied energy is ideally calculated in two stages: a preliminary estimate at the preliminary design phase (APD) to guide structure and envelope choices — while the decisive choices are still open — then a detailed calculation at the execution phase for the certification file or LCI compliance. A late calculation (after construction) allows verification but no longer optimisation.

06 — Reduction strategies

How to reduce embodied energy

Unlike operational energy, embodied energy cannot be offset after the fact: it is committed at the time of construction. Structuring decisions must therefore be made upstream, from the earliest sketches.

Bio-based and geo-sourced materials

Solid wood (CLT, glulam), cellulose fibre, hemp, straw, rammed earth, raw earth bricks: these materials have embodied energy 3 to 10 times lower than their conventional equivalents. Wood also stores atmospheric carbon (sink effect). Local geo-sourced materials (stone, earth) eliminate transport energy.

Reuse and the circular economy

Reusing an existing beam or a concrete slab eliminates almost all of the manufacturing embodied energy — only transport and refurbishment are counted. Structural reuse (floors, framing, façades) is one of the most powerful levers, still underused in French-speaking Switzerland but growing fast.

Compactness and structural optimisation

Less material means less embodied energy. A compact form reduces envelope surface area. A structure sized precisely (accurate structural calculation, optimised sections) avoids over-consumption of concrete or steel. The principle of "building lean" is the first embodied-energy move, even before the choice of materials.

Durability and ease of disassembly

A durable material is replaced only once over 60 years instead of two or three — proportionally reducing its B4 impact. Moreover, a "demountable" design (mechanical fixings rather than adhesives, reversible assemblies) enables future reuse of components: this is circular architecture in practice.

Local sourcing and short supply chains

Transport (module A4) weighs far less than material manufacturing, but remains a lever that can be acted on. Favouring certified regional timber (FSC/PEFC), insulation manufactured in Switzerland or neighbouring France, and local aggregates reduces this impact while supporting local supply chains — an argument increasingly valued in Geneva's public tenders.

07 — Labels and embodied energy

Which labels include embodied energy?

Only certain labels go beyond operational energy performance to include embodied energy and the carbon balance of materials. The table below summarises the main certifications available in French-speaking Switzerland and neighbouring France. Minergie® standard, Passivhaus Classic and Geneva's HPE/THPE levels do not appear: they cover only operational energy (REn art. 12B/12C — rsGE L 2 30.01)^{HPE (REn art. 12B) and THPE (REn art. 12C) standards, rsGE L 2 30.01: they address operational energy performance, independently of LCI art. 117-118.République et canton de Genève — Recueil systématique (silgeneve.ch) — rsGE L 2 30.01 — Règlement d'application de la loi sur l'énergie (REn), du 31 août 19881988-08-31 · accessed 2026-08-20}, the embodied carbon of materials falling under LCI art. 117–118.

Label	Embodied energy required	Standard / method	Remark
Minergie®-ECO	✓ Yes	SIA 2032 + KBOB	The complementary ECO module requires an embodied energy calculation and health/materials criteria
SNBS · DGNB	✓ Yes — central	SIA 2032 / EN 15978 + ecoinvent, ÖKOBAUDAT or KBOB	Overall sustainability frameworks, not energy labels: full LCA (A–D) weighted into the score. SNBS is required by some public clients in French-speaking Switzerland, to be checked case by case.
RE2020 (France)	✓ Yes — Ic construction	Dynamic regulatory LCA (order of 4 August 2021)	Ic construction indicator (kg CO₂-eq/m², cumulative over the 50-year reference study period)^{RE2020 guide, update of 9 May 2025, p. 21: Icconstruction_maxmoyen for apartment buildings — 740 kg CO2 eq./m² in 2022-2024, then 650, 580 and 490 from 2031; 50-year reference study period (p. 8).Ministères Aménagement du territoire et Transition écologique / Cerema — Guide RE2020 — Réglementation environnementale des bâtiments neufs (mise à jour du 9 mai 2025)2025-05-09 · accessed 2026-09-04} with thresholds tightening in 2025, 2028 and then 2031

08 — Key questions

What clients ask

Is embodied energy mandatory in Geneva?

Yes, progressively. LCI art. 117 requires limiting the embodied carbon of materials — priority to reuse, then to recycled materials — and art. 118 defines the method. The figures and the timetable come from the RECMC: see section 04. For public buildings and projects of a certain scale, a formal LCA is expected.

Does building with wood cost more?

Timber construction often carries a cost premium on the structural shell compared with conventional concrete — but this gap is shrinking as the supply chain industrialises and thanks to site-level gains (speed, dry installation). Over the whole-life cost (LCC), wood is often competitive, notably through reduced construction waste and the preserved value of components at end of life.

Can concrete be kept while still reducing embodied energy?

Yes, several levers exist: low-clinker concrete (cement substituted with fly ash or blast furnace slag), recycled concrete for certain applications, optimised structural sections, and offsetting through the choice of bio-based insulation and low-embodied-energy finishes. An optimised concrete structure can come down to ~110 MJ/m²·an, close to a standard timber building^{Consistent with the Minergie-ECO new-build limit values (p. 11: 25.0 and 36.1 kWh/m²EBF·yr, i.e. 90–130 MJ/m²·yr) and with the 42 kWh/m²·yr of SFOE guide 8719, p. 6.Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3)2021-03-31 · accessed 2026-09-04}.

At what project phase should this be addressed?

Embodied energy is essentially "won" or "lost" during the preliminary studies (EP) and preliminary design (APD) phases. A quick estimate based on a massing and a construction system is enough to guide the major choices. Waiting until the execution file to think about it means it is no longer possible to act on the decisions that really matter.

How can embodied energy be integrated into an architecture competition?

An increasing number of competitions in Geneva and Vaud include an embodied energy / carbon balance criterion in their brief. A schematic per-m² estimate (volumetric ratio based on the intended construction system) is enough at competition stage to position the project. KBOB values by construction system allow a quick comparison between variants without detailed modelling.

Key points

What to remember, and in what order to act

Fix the indicator before anything else. Write kg CO₂-eq/m²·yr into the brief: that is the figure that will be checked, not the MJ.
Estimate from the first sketch. A ratio per construction system is enough to arbitrate structure and envelope — while everything is still open.
Break the building down by trade packages. Foundations, structure, envelope, fit-out, services: the calculation and the substitutions are decided package by package.
Work from the KBOB data and standard SIA 390/1. No software is imposed: the database and the standard are what count.
Close the balance before filing the permit application. A calculation run after construction lets you record, no longer optimise.
Do not trade one balance against the other. Every extra centimetre of insulation has a carbon cost: handle energy and carbon together, from design onwards.

GenevaLCI art. 117 and 118 and the RECMC (rsGE L 5 05.05): the hierarchy reuse → recycled → low footprint, with quantified limit values. No other canton has such a regulation.

SwitzerlandNo carbon obligation on materials elsewhere in Switzerland. SIA 390/1:2025 and the KBOB data are the reference; Minergie-ECO, SNBS and DGNB take embodied energy into account, voluntarily.

Neighbouring FranceThe RE2020 requires a statutory life-cycle assessment for every new building, through the Ic construction indicator in kg CO₂-eq/m² over 50 years. Its method and scope differ from Geneva's: the two do not compare.

Sources and references (25)

Every figure and every claim in this dossier links back to its source. Hover or tap a footnote marker to see it.

Source to be established — unverified figure
Publication date of this guide, aligned with the page's schema.org markup (datePublished and dateModified: 2026-06-15).
Office fédéral de l'énergie (OFEN) / SuisseEnergie — L'énergie grise dans les nouveaux bâtiments — Guide pour les professionnels (2017-06 · accessed 2026-09-04)
SFOE/SwissEnergy, "Embodied energy in new buildings" (06.2017), p. 6: 42.0 kWh/m²·yr of embodied energy out of 158.9 kWh/m²·yr in total for a low-consumption apartment building, i.e. about 26%.
Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3) (2021-03-31 · accessed 2026-08-20)
Minergie, embodied energy calculation method (2021): building service life of 60 years, component amortisation periods taken from the SIA 2032 technical guideline.
République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.05 (2025-10-15 · accessed 2026-08-20)
RECMC (rsGE L 5 05.05, 15.10.2025): 11.3 kg CO₂-eq/m²/yr for new housing and 12.6 for administration, schools, retail and restaurants; ecobau places new build between 5 and 10.5.
Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3) (2021-03-31 · accessed 2026-09-04)
Minergie-ECO, p. 11, new-build limit values (Wohnen MFH): GW1 25.0 and GW2 36.1 kWh/m²EBF·yr, i.e. 90–130 MJ/m²·yr; SFOE guide 8719, p. 6, gives embodied energy as 42 kWh/m²·yr (151 MJ).
Société suisse des ingénieurs et des architectes (SIA) — Cahier technique SIA 2032 « L'énergie grise des bâtiments » — correctif C1:2013 à l'édition 2010, annexe C (durées d'amortissement) (2013 · accessed 2026-09-04)
Corrigendum C1:2013 to SIA 2032:2010, annex C: 60 years for excavation and structure (B, C), 30 to 40 years for the envelope (E, F), 20 to 30 years for building services (D) — 40 years for borehole probes alone.
Confédération suisse — kbob.admin.ch — Conférence de coordination des services de la construction et des immeubles des maîtres d'ouvrage publics KBOB (accessed 2026-08-20)
Official name on kbob.admin.ch: Koordinationskonferenz der Bau- und Liegenschaftsorgane der öffentlichen Bauherren — the Swiss public-sector building owners' coordination conference.
République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.05 (2025-10-15 · accessed 2026-09-04)
The RECMC uses neither "surface de référence énergétique" nor "SRE": its annex states limit values in kg CO2 eq./m2/an and refers the calculation to standard SIA 390/1:2025 (art. 3 para. 2, art. 5 para. 2).
ecobau — Bâtiments à faibles émissions de gaz à effet de serre — guide pour les maîtres d'ouvrages (état juin 2025, V1-0) (2025-06 · accessed 2026-09-04)
ecobau, "Bâtiments à faibles émissions de gaz à effet de serre", June 2025, V1-0, table 4 p. 22 (kg CO₂-eq/m²SRE·yr): new build, "moyenne" column, timber 6 against 8 massive; "bas" column, timber 5 to 5.5.
Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3) (2021-03-31 · accessed 2026-09-04)
Series calibrated on the Minergie-ECO new-build limit values (p. 11: 25.0 and 36.1 kWh/m²EBF·yr, i.e. 90–130 MJ/m²·yr) and on the 42 kWh/m²·yr (151 MJ) of SFOE guide 8719, p. 6.
Office fédéral de l'énergie (OFEN) / SuisseEnergie — L'énergie grise dans les nouveaux bâtiments — Guide pour les professionnels (accessed 2026-09-04)
SFOE, guide to embodied energy in new buildings, p. 12: "about one third" for the structural shell (group C), "one fifth each" for interior fit-out (G) and services (D); C, D and G offer the greatest potential.
Lignum — Économie suisse du bois — Bois et CO2 (accessed 2026-08-20)
Lignum: "One cubic metre of wood stores the carbon of about one tonne of CO₂." The timber/concrete gap at building scale comes from ecobau (new housing: 6 against 8 kg).
KBOB / eco-bau / IPB — Ökobilanzdaten im Baubereich / Données des écobilans dans la construction 2009/1:2016 (2016-09 · accessed 2026-08-20)
KBOB, life cycle inventory data for construction: 0.682 kg CO₂-eq/kg for reinforcing steel and 0.734 for structural steel; ~20 GJ/t is the world average of the blast-furnace route.
République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.05 (2025-10-15 · accessed 2026-08-20)
Official title cited in the RECMC preamble: "loi sur les constructions et les installations diverses, du 14 avril 1988" (LCI, rsGE L 5 05), art. 117 and 118.
MLL Legal — MLL News Portal — L'empreinte carbone au cœur du droit genevois de la construction (accessed 2026-08-20)
LCI art. 117 (from PL 12869): new builds and major renovations must minimise the carbon footprint, favouring reuse first, then recycled or low-carbon materials.
Chantiers Magazine — Zéro déchet — Rénovation durable au cœur de Genève (2022-11-28 · accessed 2026-08-20)
Chantiers Magazine (28.11.2022): works started in 2022 and the site is presented as the first "zero waste" project in French-speaking Switzerland.
République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.05 (2025-10-15 · accessed 2026-08-20)
RECMC adopted 15.10.2025, in force 22.10.2025: renovation 5 kg CO₂-eq/m²/yr; new build 11.3 (housing) and 12.6 (administration, schools, retail, restaurants), based on SIA 390/1:2025.
République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.05 (2025-10-15 · accessed 2026-08-20)
RECMC (rsGE L 5 05.05): low-carbon concept mandatory from 2029, limit values applying to State buildings from 2027 and to all projects from 2034.
République et canton de Genève — Recueil systématique (silgeneve.ch) — rsGE L 2 30.01 — Règlement d'application de la loi sur l'énergie (REn), du 31 août 1988 (1988-08-31 · accessed 2026-08-20)
The REn is the implementing regulation of the Energy Act and carries the number rsGE L 2 30.01; its art. 12B (HPE) and 12C (THPE) define the Geneva standards.
Espazium — Les éditions pour la culture du bâti — La SIA pose de nouveaux jalons pour une construction respectueuse du climat (2025 · accessed 2026-09-04)
Espazium: standard SIA 390/1 "The Climate Path – Greenhouse gas balance over the life cycle of buildings" was published on 1 February 2025 and replaces the SIA 2040 technical guideline.
Société Suisse des Entrepreneurs — Section de Genève — Point contact « Nouvelle plateforme bilan carbone chantier (BCC) » (2025-10-09 · accessed 2026-09-04)
SSE Geneva, contact point of 09.10.2025: the BCC platform was "lancée en 2025 pour remplacer l'ancien outil Bilan Carbone Chantier et Bâtiment (B2CB), développé en 2014 par la SSE Genève" with the State and SIG.
République et canton de Genève — Recueil systématique (silgeneve.ch) — Règlement concernant l'empreinte carbone des matériaux de construction (RECMC), rsGE L 5 05.05 (2025-10-15 · accessed 2026-08-20)
RECMC art. 5 and 6: the calculation is based first and foremost on the KBOB database and on standard SIA 390/1:2025, by work domain; no software is prescribed.
République et canton de Genève — Recueil systématique (silgeneve.ch) — rsGE L 2 30.01 — Règlement d'application de la loi sur l'énergie (REn), du 31 août 1988 (1988-08-31 · accessed 2026-08-20)
HPE (REn art. 12B) and THPE (REn art. 12C) standards, rsGE L 2 30.01: they address operational energy performance, independently of LCI art. 117-118.
Ministères Aménagement du territoire et Transition écologique / Cerema — Guide RE2020 — Réglementation environnementale des bâtiments neufs (mise à jour du 9 mai 2025) (2025-05-09 · accessed 2026-09-04)
RE2020 guide, update of 9 May 2025, p. 21: Icconstruction_maxmoyen for apartment buildings — 740 kg CO2 eq./m² in 2022-2024, then 650, 580 and 490 from 2031; 50-year reference study period (p. 8).
Minergie Suisse — Berechnung der Grauen Energie und der Treibhausgasemissionen bei Minergie-ECO (v1.3) (2021-03-31 · accessed 2026-09-04)
Consistent with the Minergie-ECO new-build limit values (p. 11: 25.0 and 36.1 kWh/m²EBF·yr, i.e. 90–130 MJ/m²·yr) and with the 42 kWh/m²·yr of SFOE guide 8719, p. 6.