Alteresco
Alteresco is an energy and environmental rehabilitation ensemblier (general contractor) based in Nantes, France, and a wholly-owned subsidiary of the ALTYN Group. It delivers industrialized, prefabricated energy retrofits and performance-guaranteed contracts for social housing, public, and private tertiary building owners across five French regions.
- Company typePrivate
- Founded-
- HeadquartersNantes, France
- Headcount11–50
- GTM typeB2B
- OfferingServices
What Alteresco does
Alteresco is an energy and environmental rehabilitation ensemblier (general contractor) headquartered in Nantes, France, operating as the wholly-owned 'Pôle Opérations Globales' of the ALTYN Group. The company delivers whole-building energy retrofits for social housing providers, public authorities, and private tertiary owners across five French regions (Grand Ouest, Île-de-France, Hauts-de-France, Nouvelle-Aquitaine, Auvergne-Rhône-Alpes), targeting regulatory compliance with the Décret Tertiaire 2050 trajectory and SNBC decarbonization commitments.
The company's core technology is industrialized mass renovation: prefabricated wood-frame facade systems (Façade Ossature Bois / FOB) manufactured off-site and installed at documented rates of 9+ panels per day, combined with the EnergieSprong methodology originated in the Netherlands. The flagship commercial differentiator is the Garantie de Performance Énergétique Réelle (GPE-R) — a 5-year contractual guarantee (extendable to 20 years) backed by an insurance product that commits to actual measured post-renovation energy consumption rather than theoretical models. Continuous verification is enabled by the group's digital GTB/GTC stack delivered via sister subsidiary CYRISEA.
Revenue is generated through four streams: (1) lump-sum Conception-Réalisation (design-build) contracts; (2) outcome-based CPE/GPE-R performance contracts with multi-year measurement obligations; (3) recurring Exploitation-Maintenance services bundled with performance contracts; and (4) CEE (Certificats d'Économies d'Énergie) and tier-financing advisory that can self-finance the GPE-R engineering component and enable zero-capex client renovations. Notable contracts include 224-unit Bourderies (NMH, €20.2M HT), 251-unit Georges Gauthier (Sarthe Habitat), 142-unit VILOGIA Roubaix, and the Université Paris 8 EnergieSprong retrofit (€4.9M HT, 20-year guarantee). The company holds LUCIE 26000 ESG certification (864/1000) and société à mission status, and operates through a 30+ partner/subcontractor ecosystem alongside ALTYN sister entities ALTEREA, CYRISEA, AVELTYS, BECIA, DUJARDIN, and A2MO.
Alteresco firmographics
Firmographics- Name
- Alteresco
- Legal name
- ALTERESCO
- Website
- https://alteresco.fr
- Company type
- Private
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Alteresco is an energy and environmental rehabilitation ensemblier (general contractor) based in Nantes, France, and a wholly-owned subsidiary of the ALTYN Group. It delivers industrialized, prefabricated energy retrofits and performance-guaranteed contracts for social housing, public, and private tertiary building owners across five French regions.
- Ownership category
- akta.pro rank
Where Alteresco is headquartered
LocationHeadquarters
- HQ city
- Nantes
- HQ country
- France
- HQ region
- Europe
Offices4 records
Markets served
Alteresco business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales
Revenue model
- Conception-Réalisation (Design-Build Contracts): ALTERESCO acts as general contractor and ensemblier for energy renovation projects, covering design, execution, and commissioning of whole-building retrofits for social housing, public tertiary, and private tertiary clients. Revenue is generated through lump-sum project contracts.
- Contrat de Performance Énergétique (CPE) / GPE-R: Performance-based contracts where ALTERESCO guarantees real energy savings over a multi-year period (5 years standard for GPE-R). The company is remunerated based on verified energy performance, with penalties or corrective actions if targets are not met. On some projects (e.g., Université Paris 8), a 20-year performance commitment is made.
- Exploitation-Maintenance (Operation & Maintenance Services): Post-construction phase services ensuring long-term building performance through monitoring, maintenance, and energy management. Often bundled within CPE/GPE-R contracts or provided separately as part of ongoing client relationships.
- CEE Financing & Tier-Financing Advisory: ALTERESCO assists clients in accessing Certificates d'Économies d'Énergie (CEE) subsidies and tier-financing solutions, acting as AMO (Assistance à Maîtrise d'Ouvrage) to structure project financing. Bonuses from CEE can self-finance the GPE-R engineering component.
Go-to-market motion1 record
Distribution channels1 record
Marketing channels5 records
Alteresco product offering
Product offeringCore offering
Alteresco is a French ensemblier (general contractor) delivering energy and environmental rehabilitation of residential, public, and private tertiary buildings. It bundles design, construction, maintenance, and tier-financing under a guaranteed real energy performance commitment (GPE-R), using industrialized methodologies such as EnergieSprong and prefabricated façade systems.
Product overview
ALTERESCO is a rehabilitation ensemblier (general contractor) offering a comprehensive suite of energy and environmental building renovation services. The core offering is ALTERESCO itself as the main brand, supported by specialized service modules including Conception-Réalisation (design-build), Travaux (construction works), Exploitation-Maintenance (facility management), and Financement CEE et Tiers Financement (energy certificates and third-party financing). The company also offers proprietary products including the Garantie de Performance Énergétique Réelle (GPE-R) — a unique 5-year contractual energy performance guarantee with insurance coverage — and the Contrat de Performance Énergétique (CPE) for long-term energy savings commitments. ALTERESCO operates across three main sectors: Habitat (social housing), Tertiaire Public (public tertiary buildings), and Tertiaire Privé (private commercial real estate). The company is notably pioneering in France the EnergieSprong methodology for massified prefabricated renovation and offers general contracting services (Entreprise Générale TCE) through its network within the ALTYN Group.
Differentiator
Problem solved
Functional benefit
Products and services
- Conception-Réalisation (Design-Build) Integrated design and construction of energy renovation projects for residential and tertiary buildings, combining engineering studies, architectural design, and on-site execution under a single contract. Targeted at social housing providers, public authorities, and private property managers seeking a single point of accountability.
- Entreprise Générale TCE (Tous Corps d'État) Full general contracting across all building trades (structural, envelope, technical systems, finishing) for energy renovation projects. Provides clients with a single contractual counterparty for multi-trade retrofit works.
- Travaux (Renovation Works) On-site execution of energy and environmental renovation works, including installation of prefabricated façades, envelope upgrades, and technical systems. Targets clients renovating existing residential and tertiary buildings.
- Exploitation-Maintenance (Operation & Maintenance) Multi-year operation and maintenance of renovated buildings, including technical systems upkeep, GTB/GTC monitoring, and performance verification under the GPE-R guarantee. Provided to clients who require ongoing accountability for energy performance.
- Contrat de Performance Énergétique GPE-R (Guaranteed Real Energy Performance Contract) Energy performance contract committing Alteresco to a guaranteed level of real energy consumption following renovation, with remuneration tied to achieved energy savings. Sold to social housing providers, public authorities, and private property managers who need bankable, long-term performance guarantees.
- Financement CEE et Tiers Financement (Energy Certificates and Third-Party Financing) Financing solutions for energy renovation projects, including valorisation of CEE (Certificats d'Économies d'Énergie) and tier-financing (third-party financing) structures. Targeted at clients who want to reduce or eliminate upfront capital outlay for energy works.
Companies that use Alteresco
Customer profileNamed customers15 records
Segments3 records
Ideal customer profiles3 records
Alteresco technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
Alteresco partnerships and signals
Strategic signalPartnerships
13 partnerships are on record, tiered core, major and minor.
- Groupe ALTYNcoreALTERESCO is a wholly-owned subsidiary of the ALTYN Group. The group provides shared services, brand, commercial network, and an ecosystem of specialized subsidiaries (ALTEREA, CYRISEA, AVELTYS, BECIA, DUJARDIN, A2MO) that ALTERESCO draws upon for engineering, execution, exploitation, and digital capabilities. The relationship is a core pillar of ALTERESCO's competitive positioning as an 'ensemblier'.
- ALTEREAcoreALTEREA is the engineering and consulting arm of ALTYN Group. It provides energy studies, AMO (assistance to project owner), and master engineering (MOE) services that complement ALTERESCO's role as ensemblier and general contractor. The two companies frequently appear together on projects (e.g., Georges Gauthier, NMH Bourderies, Université Paris 8).
- CYRISEAcoreCYRISEA is the GTB (Gestion Technique du Bâtiment) integrator and digital energy performance specialist of the ALTYN Group. It provides multi-brand GTB/GTC integration, performance monitoring, and digital solutions for ALTERESCO's renovation projects, enabling the GPE-R guarantee through continuous measurement and verification.
- AVELTYScoreAVELTYS is the building exploitation and operations specialist of ALTYN Group. It provides commissioning, operation-maintenance, and performance guarantee services for ALTERESCO projects. It appears as the exploitant on several ALTERESCO projects (e.g., Groupe scolaire Pasteur, Agence de l'Eau Douai).
- BECIAcoreBECIA is a general building contractor (entreprise générale TCE) operating in Île-de-France, part of the ALTYN Travaux pole alongside ALTERESCO and DUJARDIN. It provides construction and rehabilitation execution capacity for ALTERESCO projects in the Île-de-France region (e.g., École Marcel Cachin, Pantin).
- DUJARDINcoreDUJARDIN is a general works contractor (entreprise générale de travaux) specialized in rehabilitation and energy improvement, established 1972. Part of ALTYN Travaux pole, it provides execution capacity for ALTERESCO projects, notably in the Hauts-de-France region (e.g., VILOGIA projects in Roubaix, Lille Métropole Habitat).
- Floret-Scheide ArchitectesmajorArchitecture firm collaborating with ALTERESCO on multiple EnergieSprong projects including Georges Gauthier (Le Mans), Résidence Bourderies (Nantes), Résidence Rosier et Debussy (Allonnes), and Résidence Moulin du Bois (Saint-Herblain). Provides architectural design for prefabricated facade systems.
- Swan ArchitectesmajorArchitecture firm serving as architect on ALTERESCO's Groupe scolaire Pasteur project (Neuilly-sur-Marne) and École Marcel Cachin project (Pantin). Provides architectural design and oversight for public tertiary renovation projects.
- Méandre etc' ArchitecturemajorArchitecture firm collaborating with ALTERESCO and ALTEREA on the Université Paris 8 EnergieSprong retrofit project, providing architectural design for the renovation of Buildings C and C'.
- REXELminorElectrical equipment and materials distributor referenced as a project partner on the NMH Résidence Bourderies project, providing electrical components for the renovation works.
- BesteelminorSteel fabrication company based near Brussels (périphérie de Bruxelles) responsible for factory prefabrication of structural panels for the Ville de Lille school renovation project (EnergieSprong approach), which ALTERESCO installed on-site.
- Pierre Louis Carlier ArchitectesmajorArchitecture firm providing architectural design for the VILOGIA 221+6 dwellings rehabilitation project in Marquette-lez-Lille and Saint-André-lez-Lille, a major social housing renovation project under ALTERESCO's execution.
- MANERGYminorAMO (Assistant à Maîtrise d'Ouvrage) on the Groupe scolaire Pasteur project (Neuilly-sur-Marne), providing advisory and project management support services alongside ALTERESCO as mandataire.
Scale indicators6 records
Recent moves6 records
Expansion highlights6 records
Alteresco competitors and assessment
Company assessmentMarket position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key highlights7 records
Customer concentration
Alteresco social profiles
Digital presenceAlteresco compliance and trust
Trust signalCompliance2 records
Alteresco financial estimates
Financial estimateRevenue estimate
Valuation estimate
Alteresco leadership team
Management profileNumber of profiles
Profiles8 records
Alteresco funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Alteresco M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Alteresco
What does Alteresco do?
Alteresco is a French ensemblier (general contractor) delivering energy and environmental rehabilitation of residential, public, and private tertiary buildings. It bundles design, construction, maintenance, and tier-financing under a guaranteed real energy performance commitment (GPE-R), using industrialized methodologies such as EnergieSprong and prefabricated façade systems.
Is Alteresco a public or private company?
Alteresco is a private company. It is classified as corporate owned and is currently operating.
When was Alteresco founded?
Alteresco was founded in -1. It employs 11 to 50 people.
Where is Alteresco based?
Alteresco is headquartered in Nantes, France, in the Europe region.
How does Alteresco make money?
Four revenue lines are on record. Conception-Réalisation (Design-Build Contracts) is the primary driver. The others are contrat de Performance Énergétique (CPE) / GPE-R, exploitation-Maintenance (Operation & Maintenance Services) and CEE Financing & Tier-Financing Advisory.
Does Alteresco have an API?
No public API is recorded for Alteresco.