ECIA is a European non-governmental and non-political not-for-profit organization, registered under the Belgian law. ECIA is a representative body of national member organizations. ECIA members are National Professional Organizations of Interior Architects whose objectives and activities can be described as follows:

• The member organization is an independent professional body or a section of an umbrella-type professional association that is able to demonstrate that its constitution and statutes comply with the shared ECIA’s objectives.
• The member organization has the primary objective to develope and promote Interior Architecture as a profession.
• The member organization operates on a national level. 
• The member organization can demonstrate that it is endorsed and registered with relevant authority in its member state.
• The member organization consists of individual members or regional chapters.
• The individual members of a national organization or its chapters are Interior Architects and comply to the professional and educational standards as set  in ECIA policy documents.

ECIA Member Associations

• Associatie van Interieurarchitecten van België AinB Association des Architectes d' Intérieur de Belgique asbl Belgium - België - Belgique
• Associazione Italiana Progettisti in Architettura di Interni AIPi Italy - Italia
• Bund Deutscher Innen Architekten BDIA Germany - Deutschland
• Bund Österreichischer Innenarchitekten BÖIA Austria - Österreich
• Beroepsvereniging Nederlandse Interieurarchitecten BNI Netherlands – Nederland
• Consejo General De Los Colegios Oficiales De Decoradores Diseòadores De Interior CGDI Spain – España
• Eesti Sisearhitektide Liit Eesti - Estonia - l'Estonie
• Félag húsgagna- og innanhússarkitekta FHI Iceland – Ísland
• Institute of Designers in Ireland IDI Ireland – Éire
• Norske interiør-arkitekters og møbeldesigneres landsforening NIL Norway – Norge - Noreg
• Society of British Interior Design United Kingdom - Grande Bretagne - UK
• Sveriges Arkitekter Sweden – Sverige
• Sisustusarkkitehdit Inredningsarkitekterna SIO Finland – Suomi
• Fédération Nationale des Syndicats d’Architectes d’Intérieur FNSAI France
• Vereinigung Schweizer Innenarchitekten/architektinnen VSI-ASAI Association Suisse des Architectes d’Intérieur Associazione Svizzera degli Architetti d’Interni Switzerland – Suisse - Schweiz - Svizzera
• Zwi¹zek Polskich Artystów Plastyków ZPAP Poland – Polska