A Paris-based startup is betting that interior designers are tired of wrestling with AutoCAD's decades-old interface. Rayon, which builds browser-based drafting software tailored for architects and interior designers, announced a €10 million Series A round led by Partech on September 29, bringing total funding to €15.7 million since the company launched in October 2021.
The round drew participation from Northzone, Foundamental and Seedcamp, all returning investors who have backed the company through earlier stages. Partech disclosed the financing details in a press release dated September 29.
Co-founders Bastien Dolla and Stanislas Chaillou are tackling a market that AutoCAD has dominated for decades, though their pitch centers less on dethroning the incumbent and more on serving a specific subset of users whose needs have evolved faster than the software. "Our superpower is to make professional-grade CAD software approachable," Dolla said in the announcement. Interior designers, the founders argue, need tools built for their workflows rather than repurposed from broader architectural suites.
Rayon's browser-based platform offers real-time collaboration and AI-assisted drafting, features that legacy desktop software has been slow to adopt. The company said users have created more than 4 million drawings on the platform as of late September, a figure that speaks to early traction even if it doesn't reveal how many of those users are paying customers. The 35-person team has landed contracts with Virgin Atlantic airport lounges, hospitality operator CityHub, and co-living firm Coloc Housing, according to Partech.
CityHub reported on its case study page that Rayon saves the company roughly €10,000 per month on feasibility studies. "Rayon has transformed the way we evaluate real estate opportunities," said Martial Robardet, the firm's head of expansion. "It's a game changer." Coloc Housing cited similar savings, claiming the platform cut about €11,000 monthly from its budget by bringing feasibility work in-house.
Those cost reductions hinge on Rayon's ability to accelerate what is typically grunt work: converting images into vector floor plans, populating drawings with furniture and fixtures from a library of more than 4,000 items, and coordinating edits across teams in real time. The software supports standard file formats including DWG, DXF and PDF, a nod to interoperability with the broader design ecosystem. Version history and link sharing round out the collaboration features.

The company's AI capabilities have expanded quickly, perhaps more quickly than some early users anticipated. Rayon shipped what it called Version 3 in late August, adding a new AI panel, presentation mode, parametric blocks and expanded libraries, Chaillou wrote on LinkedIn. Version 4 is slated for later this year and will integrate 3D modeling alongside what the company describes as "agentic AI" into the same browser workspace, according to a September 23 blog post.
Chaillou brings an unusual pedigree to the role. Before co-founding Rayon, he worked as a machine learning engineer at Spacemaker AI and earned a master's in architecture from Harvard's Graduate School of Design, where he published research on AI and architecture, according to a university alumni update. "Interior design needs its own approach to AI, not a borrowed one," he said in the Partech release.
The new capital will fund the 3D modeling rollout and deeper AI integration, as well as scaling sales and marketing. Current pricing sits at €0 for a free tier, €19 per month for Pro accounts, and €35 per editor per month for Team plans, with AI credits allocated weekly, according to the company's pricing page captured September 30.

Rayon's funding history reflects steady investor confidence. The startup raised a €1.7 million pre-seed led by Seedcamp with Foundamental and 20VC in 2022, followed by a €4 million seed round co-led by Northzone and Foundamental that same year, according to company announcements. Angel investors from earlier rounds include architect Norman Foster of Foster + Partners, ArchDaily founder David Basulto, and former Loom executive Joe Thomas.
Partech general partner Réza Malekzadeh framed the investment as opportunistic. "What drew us to Rayon is how rare this kind of opportunity actually is," he said in the September 29 press release. Northzone partner Michiel Kotting emphasized the verticalized approach, noting the firm is "building specifically for the needs of interior designers."
AEC Magazine described Rayon in a February feature as "squaring off against AutoCAD in the world of drawings," serving teams whose work remains largely two-dimensional. The company lists AutoCAD, SketchUp, Vectorworks, Revit and ArchiCAD among alternatives on its pricing page, a roster that spans both heavyweight enterprise tools and nimbler challengers.
The addressable market is sizable, if sprawling. Mordor Intelligence estimated the global interior design software market at $7.59 billion in its most recent dataset, with projections reaching $12.86 billion by 2031. Those figures encompass everything from consumer-facing room planners to enterprise design suites, making it difficult to parse exactly where Rayon fits on the spectrum. What's clearer is that the company is carving out a niche somewhere between hobbyist tools and the bloated complexity of traditional CAD, betting that a generation of designers will choose purpose-built simplicity over legacy power.
