Record checked on 26 October 2026.
ALTA Architectes – Urbanistes
Architecture firm in Rennes · founded in 2002
Formerly a/LTA (Le Trionnaire x2 Tassot Le Chapelain)
Overview
ALTA is a Rennes practice of architects and urban planners led by Maxime Le Trionnaire and Gwénaël Le Chapelain, who joined founders Jean-Luc Le Trionnaire and Alain Tassot in 2010 and later took over; Fanny Larhantec and Aurélie Morel became partners in 2023. Working mainly across Brittany and western France, the team of about thirty designs housing, schools, offices and mixed-use blocks, such as the Tour Amazonie in Nantes and the La Providence secondary school in Saint-Malo.
- Founded
- 2002
- Team
- ≈ 29
- Projects
- 8
- Awards
- 8
Founders Jean-Luc Le Trionnaire and Alain Tassot worked together in Rennes from 1990 and set up a/LTA in 2002; the current company was registered in 2004.
Partners and founders
Maxime Le TrionnaireCo-manager / Architect
Gwénaël Le ChapelainCo-manager / Architect
Fanny LarhantecPartner / Architect
Aurélie MorelPartner / Architect
Fields of work
Housing · Schools and public facilities · Office buildings · Mixed-use developments · Urban planning
Built work
Bois Harel office complex
Saint-Jacques-de-la-Lande · OfficesJean de La Fontaine school
Tours · Nursery school and canteenLa Providence secondary school and gymnasium
Saint-Malo · Secondary school and sports hallWood-fired boiler house
Saint-Pern · Technical facility50 homes, Cœur de Poulfanc eco-district
Séné · HousingLe Cours des Arts intergenerational residence, ZAC Beauregard-Quincé
Rennes · Housing with artists' studiosTour Amazonie and Attalea (151 homes and commercial space), ZAC du Pré Gauchet
Nantes · Housing and mixed usePrizes and awards
- 2025ArchDaily Building of the Year, nominee (Jean de La Fontaine school, Tours)
- 2024Architecture & Design Collection Award 2024, gold (Jean de La Fontaine school, Tours)
- 2023ECCA Prize, special mention (La Providence school, Saint-Malo)
- 2023ArchDaily Building of the Year, nominee (La Providence school, Saint-Malo)
- 2014Europe 40 Under 40
- 2010Prix d'architecture de Bretagne, shortlisted (48 homes, Saint-Malo)
- 2008Prix de la première œuvre (Le Moniteur), nominee
- 2008Prix d'architecture de Bretagne, shortlisted (Collège Lebesque, Mordelles)
Frequently asked questions
Where is ALTA Architectes – Urbanistes based?
The firm's address is 22 avenue Henri Fréville, 35200 Rennes.
When was ALTA Architectes – Urbanistes founded?
It was founded in 2002.
How can I contact ALTA Architectes – Urbanistes?
You can reach the firm by phone on +33 2 99 26 33 26, by email at contact@a-lta.fr and through its website a-lta.fr.
What are the main projects of ALTA Architectes – Urbanistes?
Its built work includes Astrolabe office building, Cleunay (Rennes, 2024), Bois Harel office complex (Saint-Jacques-de-la-Lande, 2024) and Jean de La Fontaine school (Tours, 2024).