What Elioth does

Elioth is a French engineering and design collective ("atelier d'ingénierie") founded in 2003 and headquartered in Montreuil (Paris), operating today as a brand of Egis Concept SASU within the privately-held Egis Group. The firm delivers consulting and full project supervision ("maîtrise d'œuvre d'innovation bas carbone") across four practices — Structures, Façades, Environnements, and Trajectoires — plus an internal cross-disciplinary research Lab. Its work concentrates on low-carbon buildings and urban transformation: complex geometries, high-rise timber structures, adaptive envelopes, urban heat island mitigation, and district-scale carbon planning.

The core offering is project-based professional services billed through consulting fees and full-scope contract delivery for large property developers (ICADE, Nexity, AG Real Estate, Les Nouveaux Constructeurs), public authorities (Ville de Paris, RATP, Communauté d'agglomération Caen la mer), architects (Jean-Paul Viguier, 169 Architecture, Encore Heureux), and corporates such as EDF and SNEF. Pricing is not publicly disclosed; projects are acquired via competitive tender and direct engagement. Beside services, Elioth develops and open-sources engineering tools on GitLab and QGIS — ICE/ICEtool for urban heat island analysis, DESsim for district heating/cooling, dynco2 for dynamic LCA, ghcitysim for Grasshopper microclimate work, and ReCoCO2 for collective carbon reference tracking — and holds patents linked to its Wind-it vertical-axis wind turbine technology, spun out into Wind-it SAS.

The firm operates from five offices — Paris/Montreuil (HQ), Lyon, Nice, Rennes, and London — and in 2022 merged with Openergy to form Egis Concept, organizing staff around an integrated low-carbon design offering across energy, materials, structures, facades, and carbon performance. Management is led by Pierre-Arnaud Voutay (directeur général) with Colin Hutchison as executive chairman of Egis Concept, and François Consigny holding the presidency of the Adiv Bois technical committee.

Name

Elioth

Legal name

Egis Concept

Website

https://elioth.com

Company type

Private

Founded year

2003

Operating status

Operating

Headcount range

11–50 employees

Short description

Elioth is a French engineering collective operating under Egis Concept, delivering structural, facade, and environmental design services for low-carbon buildings and urban projects to property developers, municipalities, architectural firms, and public institutions in France and the UK.

Ownership category

akta.pro rank

Product category

Sustainable Engineering Consulting

NAICS

Engineering Services (54133), Architectural Services (541310), Management, Scientific, and Technical Consulting Services (5416)

SIC

Services-Engineering Services (8711), Services-Engineering, Accounting, Research, Management (8700)

akta.pro primary industry

Civil & Structural Engineering Consulting (BPAHAIAA)

akta.pro secondary industry

Architectural Design Services (BPAHAKAA)

Keywords

• Low-carbon engineering
• Structural engineering services
• Facade engineering consulting
• Environmental design services
• Urban climate analysis

Headquarters

HQ city

Montreuil

HQ country

France

HQ region

Europe

Offices5 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Engineering Consulting: Fees for technical consulting services on structural engineering, facade engineering, and environmental design for construction projects.
2. Master Contracting (Maîtrise d'œuvre): Full project delivery services from design through construction supervision for low-carbon innovation projects.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels6 records

Core offering

Elioth is an engineering atelier providing consulting and low-carbon design services for buildings and urban projects, organized around four poles: Structures (complex geometries, high-rise timber construction), Façades (high-performance envelopes and adaptive facades), Environnements (bioclimatic design, lifecycle analysis, urban energy modeling), and Trajectoires (carbon trajectory and decarbonization roadmaps). The firm delivers services from concept through construction supervision (maîtrise d'œuvre) and supplements them with proprietary open-source tools and patented innovations developed in its internal research Lab.

Product overview

Elioth is the primary brand and service offering — an engineering and design collective (atelier d'ingénierie) under Egis Concept with over 40 multidisciplinary experts (engineers, architects, designers, data scientists) organized around four poles: Structures, Façades, Environnements, and Trajectoires, all supported by an internal cross-disciplinary research Lab. The core offering is professional consulting and low-carbon design services for buildings and urban projects. The firm also develops a portfolio of open-source tools — ICE/ICEtool (QGIS-based urban heat island analysis), DESsim (district heating/cooling network simulation), dynco2 (dynamic LCA), ghcitysim (Grasshopper-based ICU studies), and ReCoCO2 (carbon project tracking) — which are distributed freely on GitLab/GitHub as part of Elioth's open-source engineering philosophy. Key experimental concepts include Clip'n Clim (adaptive façade module) and the Variable Albedo Ground prototype. The 169 Architecture arm develops experimental low-carbon architectural projects. Notable patents include Wind-it (vertical-axis wind turbines on existing pylons/towers).

Differentiator

Problem solved

Functional benefit

Brands

• 169 Architecture: Experimental architecture laboratory associated with Elioth, focused on low-carbon experimental architecture and innovation projects.
• Egis Concept

Products and services

• Structures (Pôle Structures) Structural engineering service for complex geometries and high-rise buildings, with specialist expertise in structural timber and floor panel systems for tall timber buildings, covering fire safety, acoustic, and constructive constraints.
• Façades (Pôle Façades) Facade engineering practice delivering expertise at the intersection of engineering and architecture, focused on high-performance envelope systems, natural ventilation principles, adaptive facades, and low-carbon material strategies (e.g., timber curtain walls replacing aluminum).
• Environnements (Pôle Environnements) Environmental engineering service addressing energy transitions, climate resilience, and resource depletion across building and district scales, covering bioclimatic design, lifecycle analysis, urban energy modeling, and renewable energy system design.
• Trajectoires (Pôle Trajectoires) Strategy and foresight service that translates Elioth's low-carbon design experience into bespoke client missions, covering carbon trajectory planning, regulatory compliance, material and energy sobriety strategies, and urban decarbonization roadmaps.
• Le Lab (Research Lab) Internal cross-disciplinary research laboratory that develops proprietary and open-source tools, prototypes (e.g., Variable Albedo Ground, Clip'n Clim), patented innovations (Wind-it), and contributes to research programs and conferences. Provides R&D and innovation services to support client engagements.
• Master Contracting (Maîtrise d'œuvre) of innovation projects Full project delivery (maîtrise d'œuvre) services for low-carbon innovation projects, covering design through to construction supervision, with projects such as Tour Montparnasse renovation and Bruneseau district as flagship engagements.
• ICE / ICEtool Open-source urban heat island (ICU) evaluation tool published on GitLab/GitHub. Built as a QGIS plugin, it performs surface temperature, shadow, and energy-balance calculations for urban design scenarios, enabling microclimate mapping and quantification of mitigation measures (vegetation, cool materials, albedo changes) for architects, urban designers, environmental engineers, and municipalities.
• ReCoCO2 (Repères Collectifs Carbone) Methodology and tool (Repères Collectifs pour Piloter les Projets de Bâtiments Bas-Carbone) published as part of Elioth's open-source engineering toolkit, providing collective reference points for tracking and managing carbon in low-carbon building projects for project teams and developers.
• 169 Architecture (experimental architecture practice) Experimental architecture sub-brand associated with Elioth, delivering innovative low-carbon architectural projects such as the Marguerite de Navarre RATP cover and the COP21 plenary hall, in collaboration with Elioth's engineering expertise.
• Wind-it (vertical-axis wind turbine technology) Patented vertical-axis wind turbine technology developed by Elioth and commercialized through the dedicated startup Wind-it SAS, integrating turbines into existing electricity pylons and telecom towers for distributed wind-energy generation, telecom network energy savings, and rural electrification.
• Variable Albedo Ground prototype Experimental climate-regulating ground surface material with seasonally adaptive thermal properties (cooler in summer, warmer in winter) for urban heat island mitigation. Developed and tested by Elioth Lab as a publicly documented research prototype for district-scale deployment.
• Métabolisme.paris.fr (urban metabolism visualization platform) Public-facing web visualization platform showing energy, material, and water flows supporting Paris and Île-de-France's urban activity, built for the Ville de Paris to popularize circular economy concepts and present concrete optimization solutions to citizens and stakeholders.

Quantifiable outcome

• Tour Montparnasse energy consumption reduced by 90% compared to original project
• +3 more outcomes

Named customers12 records

Segments4 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

Feature7 records

Partnerships

Seven partnerships are on record, tiered core and flagship.

• OpenergycoreStrategic or Co-development Partner · 1 January 2022Merger to form Egis Concept, combining Elioth's engineering expertise with Openergy's energy optimization capabilities for holistic low-carbon design.
• Egis Villes Routes et MobilitéscoreTechnology or Integration · 1 January 2021Collaboration on ICE (Îlots de Chaleur Urbain) tool development for urban heat island assessment, built on QGIS and published as open source.
• Inhabit InternationalcoreStrategic or Co-development Partner · 1 January 2019Global partnership for facade and environmental design combining Elioth's European expertise with Inhabit's international resources and capabilities.
• EPFL (École Polytechnique Fédérale de Lausanne)coreStrategic or Co-development Partner · 1 January 2019Research partnership with Catherine De Wolf's team to develop methods for carbon impact assessment and circular economy evaluation beyond existing regulations and labels.
• Wind-it SAScoreStrategic or Co-development PartnerStartup company created in 2014 to accelerate Wind-it product development - vertical axis wind turbines for telecom networks.
• 169 ArchitecturecoreStrategic or Co-development PartnerExperimental architecture laboratory for innovative low-carbon building solutions including Marguerite de Navarre metro cover and COP21 plenary hall.
• Egis Group (Parent)flagshipOthersElioth is a brand of Egis Group, operating within Egis Concept alongside Openergy. Egis provides corporate backing, shared services, and cross-selling opportunities.

Scale indicators5 records

Recent moves10 records

Expansion highlights6 records

Direct peers

• Ingérop: French engineering group that partnered with Elioth on the 2018 Grand Prix-winning Nausicaá project. Comparable French engineering services portfolio with overlapping low-carbon and infrastructure capabilities.
• Buro Happold: Independent engineering consultancy with deep sustainability and structural expertise, multidisciplinary integration of structures, facades, and environment. Highly comparable to Elioth in service mix, though Buro Happold is materially larger and more internationally distributed.
• Atelier Ten: Environmental design consultancy combining building performance, facade engineering, and sustainability strategy. Closely comparable to Elioth's multidisciplinary environmental + facade + strategy offering at boutique scale.
• Werner Sobek: Engineering firm specializing in innovative structures and sustainability, with strong expertise in facades, timber construction, and low-carbon design philosophy. Closely aligned with Elioth's Structures and Façades poles.
• Transsolar: Munich-based climate engineering consultancy focused on thermal comfort, energy modeling, and urban microclimate for buildings and districts. Direct match for Elioth's Environnements and Trajectoires poles.
• Bollinger + Grohmann: German engineering firm with international offices delivering innovative structural and facade design, often in collaboration with leading architects. Comparable service portfolio and project complexity to Elioth.
• Inhabit International: Global facade and environmental design consultancy with Elioth as a strategic partner since 2019. Closest direct comparable: similar boutique scale, similar facade/environmental engineering focus, and explicit mutual partnership on cross-region projects.

Broad incumbents

• Arup: Global engineering giant with a substantial sustainability practice overlapping Elioth's environmental, facade, and structural services. Competes for the same marquee projects but at vastly greater scale and with broader service breadth.
• Artelia: Major French engineering group offering multidisciplinary building, infrastructure, and environmental services. Direct competitor in the French market for large low-carbon projects but operates at much larger scale.
• WSP: Global professional services firm with extensive engineering and sustainability advisory capabilities. Competes with Elioth on flagship sustainable buildings and district-scale carbon mandates internationally.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/elioth
• LinkedInlinkedin.com/company/elioth
• Instagraminstagram.com/elioth.egisgroup/?igshid=gparl08srnnu

Revenue estimate

Valuation estimate

Number of profiles

Profiles14 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Elioth