External Reference

What External Reference does

External Reference is a Barcelona-based experiential architecture and design firm founded in 2007 that creates immersive physical spaces for luxury retail, hospitality, food and beverage, cultural, and high-end residential clients globally. The firm operates on a project-based professional services model, executing large bespoke commissions such as the Spanish Pavilion at Expo 2020 Dubai, the Level Shoes store at Dubai Mall (96,000 sq ft), 24 Kilates sneaker boutiques in Bangkok, Plaza Mahou at the Santiago Bernabéu stadium, the WOW Concept Madrid six-floor retail concept, and the Malinska five-star resort in Croatia. Pricing for architectural services is custom-quoted, with multi-year contract cycles and enterprise sales pursued through direct outreach, international design events (Milano Design Week, Barcelona Design Week), academic partnerships, and referrals from luxury brands and developers.

The firm's core technology stack is parametric and computational design (Grasshopper/Rhinoceros) combined with a digital fabrication network spanning FDM 3D printing, 5-axis CNC milling, Murano glass blowing, molten metal casting, and AR/VR visualization for client walkthroughs. Its proprietary material platform — WEARPURE.TECH / PURE.TECH — is a 3D-printable biomaterial composite of PLA bioplastic and a 100% natural mineral compound (CO2pure) that the company claims captures and mineralizes CO2, NOx, and VOCs through photolysis, with 30+ studies cited in support. This material underpins the Air Purifier Plants / Pure Plants direct-to-consumer product line (€150–€2,500 per unit, made-to-order with 3-day lead time), which the firm is expanding to 17 size and design variants.

External Reference is led by founder and CEO Carmelo Zappulla (PhD Architect) and operates with a multidisciplinary team of approximately 40 professionals from over 17 countries, including team leaders in studio operations, computation, design, experience, R&D, and graphic design. Revenue is generated primarily through enterprise architecture commissions, supplemented by smaller streams from direct-to-consumer Air Purifier Plants sales and design consultancy. The firm maintains a Barcelona headquarters and a London prototype location, with a deep fabrication and AV partner ecosystem including LaMàquina (Noumena), Oxido Taller, OnionLab, and Lloc Audiovisuals, and academic partnerships with IAAC and LCI Barcelona that function as a talent and research pipeline.

Name

External Reference

Legal name

External Reference

Website

https://externalreference.com

Company type

Private

Founded year

2007

Operating status

Operating

Headcount range

11–50 employees

Short description

External Reference is a Barcelona-based experiential architecture and design firm (founded 2007) that creates bespoke immersive spaces for luxury retail, hospitality, F&B, and cultural clients globally, using parametric design, digital fabrication, AR/VR, and its proprietary WEARPURE.TECH CO2-absorbing material.

Ownership category

akta.pro rank

Product category

Experiential architecture and design services

NAICS

Interior Design Services (54141), Other Specialized Design Services (54149)

akta.pro primary industry

Specialty Finishes & Decorative Installations (Plaster, Stone Veneer, Feature Walls) (IMAFANAM)

akta.pro secondary industries

Joinery, Millwork & Casework Installation (Cabinetry, Built-Ins) (IMAFANAJ), Ceramic & Glass 3D Printing Services (IMAAADAC)

Keywords

• Experiential architecture design
• Retail interior design
• 3D printed decor
• Sustainable building materials
• Digital fabrication services

Headquarters

HQ city

Barcelona

HQ country

Spain

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B and B2C

Offering type

Services

Cost components

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

Revenue model

1. Architecture & Experiential Design Projects: Full-service architecture and design commissions for retail, hospitality, restaurants, corporate, exhibition, urban design, and product design. Revenue is project-based, typically large enterprise contracts for bespoke experiential spaces. Clients include luxury fashion brands, restaurant groups, hotel developers, and real estate companies across Europe, Middle East, and Asia.
2. AIR PURIFIER PLANTS / Pure Plants Products: Sale of 3D printed decorative plants (trees, cacti, succulents) made with WEARPURE.TECH / PURE.TECH material. Products are sold directly via the company website on a made-to-order basis. Price range from €150 to €2,500 per piece. Printing lead time of 3 days. Revenue is one-time per transaction.
3. Design Consultancy: External Reference vision and technical assistance provided as consultants to external clients. Engagements include concept development and technical assistance in design projects where the External Reference philosophy is incorporated into third-party initiatives.

Pricing tiers

Go-to-market motion3 records

Distribution channels2 records

Marketing channels6 records

Core offering

External Reference is an experiential architecture and design firm that designs and delivers bespoke retail, hospitality, exhibition, product, urban, and residential projects for premium brands and institutions worldwide. The firm combines parametric/computational design with digital fabrication (3D printing, CNC milling, glass blowing, metal casting) and AR/VR visualization, supported by a multidisciplinary team of 40 professionals from over 17 countries. It also sells a proprietary consumer product line — Air Purifier Plants / Pure Plants — 3D printed decorative plants made from its proprietary WEARPURE.TECH/PURE.TECH biomaterial that absorbs CO2, NOx, and VOCs through photolysis.

Product overview

External Reference is an experiential architecture and design firm based in Barcelona that creates immersive spaces blending architecture, art, and digital tools. The company operates a services-based model offering retail, hospitality, architecture, exhibition, product, and urban design services, complemented by proprietary product lines including the Air Purifier Plants/Pure Plants family (3D printed air-purifying sculptural plants using WEARPURE.TECH/PURE.TECH material that absorb CO2), custom furniture pieces (Manglar Chair, Mangrove Table, Spinal Table, Milky Table, Aura Chair), and art installations (Light Scape). The firm combines craftsmanship with cutting-edge technologies including CNC milling, digital fabrication, 3D printing, Murano glass blowing, molten metal casting, and AR/VR simulations to deliver bespoke experiential projects globally.

Differentiator

Problem solved

Functional benefit

Brands

• Air Purifier Plants: Family of 3D printed decorative plants made with WEARPURE.TECH material capable of absorbing CO2 and purifying air.
• Pure Plants
• WEARPURE.TECH
• PURE.TECH

Products and services

• Architecture & Experiential Design Services Full-service architecture and design commissions covering retail, hospitality, restaurants, exhibition, product, urban, and residential design for enterprise clients. Projects integrate parametric/computational design, digital fabrication, AR/VR visualization, and bespoke furniture to deliver immersive brand environments globally.
• Air Purifier Plants / Pure Plants A family of 3D printed decorative plants (trees, cacti, succulents) made from bioplastic PLA mixed with WEARPURE.TECH / PURE.TECH mineral compound that absorbs and neutralizes CO2, NOx, and VOCs through photolysis. Designed with parametric tools translating natural phyllotaxis patterns, available on a made-to-order basis with a 3-day 3D printing lead time.
• Drimia Maritima 3D printed decorative plant inspired by Mediterranean vegetation, featuring a large bulb. Dimensions 90 x 28 cm, weight 11 kg, priced at €500, made with PLA bioplastic with WEARPURE.TECH.
• Cereus Forbesii Spiralis 3D printed cactus with spiral form available in two sizes: 45 x 20 cm (5 kg, €500) and 25 x 16 cm (3 kg, €250), made with PLA bioplastic with WEARPURE.TECH.
• PureTree Sculptural 3D printed Christmas tree following phyllotactic spirals, completed with LED lighting and handmade glass. Absorbs more than 15 kg of CO2 per year. Dimensions 180 x 80 cm, weight 22 kg, priced at €2,500, with prototypes in Barcelona (Sayrach Office Club) and London.
• Artichoke Agave 3D printed succulent plant inspired by the Agave genus. Dimensions 8 x 8 cm, weight 0.5 kg, priced at €150, made with PLA bioplastic with WEARPURE.TECH.
• Light Scape Art Installation Artwork that transforms Barcelona's city sounds into visual light using advanced parametric design to convert sound frequencies into 3D visual representations.
• Design Consultancy Services Concept development and technical assistance in design projects where the External Reference philosophy is incorporated into third-party initiatives.

Quantifiable outcome

• PureTree absorbs more than 15 kg of CO2 per year through photolysis — equivalent to the absorption of a real 30-year-old, 8-meter tree
• +4 more outcomes

Named customers13 records

Segments6 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Ten partnerships are on record, tiered core and major.

• IAAC — Institute for Advanced Architecture of CataloniacoreStrategic or Co-development PartnerOngoing academic and research partnership. Founder Carmelo Zappulla serves as Faculty member at IAAC. External Reference co-directs Studio G2 at IAAC with Claudia Pasquero, investigating urban environments from a non-anthropocentric perspective. IAAC serves as both a talent pipeline and a research incubator for the firm. Collaboration includes student projects, research publications, and joint studio investigations in biotechnology applied to architecture.
• LCI BarcelonacoreStrategic or Co-development PartnerOngoing academic partnership. Carmelo Zappulla directs the Master in Experiential Interior Design at LCI Barcelona. Multiple team members serve as tutors in this program (Sebastian Amorelli — Parametric tools; Stefano Fontolan — Representation tools; Vianella Maestra — Academic coordinator). The partnership serves as a talent pipeline and thought leadership platform for the firm.
• LaMàquina by NoumenacoreTechnology or IntegrationState-of-the-art advanced manufacturing partner specializing in 3D printing solutions for architecture and design. Responsible for manufacturing Pure Plants product line and complex 3D printed elements across multiple projects including CAAA Lucerne restaurant, Sayrach Principal Office Club, and Riyadh Presentedby. Long-standing collaboration across dozens of projects since at least 2020.
• Oxido TallercoreTechnology or IntegrationPrimary fabrication and digital workshop partner across a wide range of projects including WOW Concept Madrid, Level Shoes Dubai, Doha Presentedby, Bershka Custom House, Riyadh Presentedby, Crep Protect Dubai, and multiple other projects. Provides digital fabrication expertise, metalwork, and production capabilities essential to project execution.
• NoumenacoreTechnology or IntegrationResearch and fabrication collective specializing in computational design, digital fabrication, and advanced manufacturing. Collaborated on Mangrove Table, Manglar Chair, Level Shoes Dubai, Riyadh Presentedby, and CAAA Lucerne. Provides algorithmic design, parametric modeling, and advanced fabrication capabilities.
• Lloc AudiovisualsmajorTechnology or IntegrationAudiovisual and interactive technology partner across multiple experiential retail projects including Level Shoes Dubai, Doha Presentedby, Riyadh Presentedby, and Harvey Nichols London. Provides projection mapping, interactive installations, and multimedia content systems integral to the experiential retail environments.
• OnionLabmajorTechnology or IntegrationDigital and multimedia design studio providing projection mapping, audiovisual installations, and interactive content across major projects including Spanish Pavilion Expo Dubai, Casa Moritz, Level Shoes Dubai, Doha Presentedby, Riyadh Presentedby, and WOW Concept Madrid. Integral to creating the immersive digital environments that characterize External Reference's experiential spaces.
• Barcelona Glass StudiomajorTechnology or IntegrationTraditional and artisanal glass fabrication partner contributing to Moritz M-store Barcelona and Casa Moritz projects. Provides hand-blown glass elements and artistic glasswork that integrate traditional Murano-style craftsmanship with modern design — a key differentiator in the 'Artisanship 2.0' approach.
• La MaquinacoreTechnology or IntegrationFabrication partner for the 3D Printed Christmas Tree Barcelona (2020) project. Collaborated on printing and manufacturing complex 3D printed elements. Also involved in Plaza Mahou Madrid project. Long-standing partnership providing advanced manufacturing capabilities.
• Oxido StudiomajorTechnology or IntegrationDigital and design studio contributing to Yeosu Spanish Pavilion, Moritz M-store, Jane Winestore, Casa Moritz, VA de Cuina, and CAAA Lucerne. Provides multimedia, digital fabrication, and design integration across architectural and interior design projects.

Scale indicators5 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Heatherwick Studio: London-based experiential architecture and design studio combining art, architecture, and public-realm installations for global luxury, cultural, and civic clients. Closely comparable to External Reference in studio size, multidisciplinary positioning, and brand-led experiential commissions.
• UNStudio: Amsterdam-based network architecture firm specializing in parametric and data-driven design for cultural, commercial, and residential projects worldwide. Comparable in its computational/parametric design DNA and its mix of product, interior, and architectural commissions.
• MAD Architects: Beijing-based architecture practice led by Ma Yansong, known for parametric, nature-inspired forms in cultural and mixed-use projects. Comparable in its use of parametric phyllotaxis-inspired and biomorphic design language for experiential buildings.
• Aranda\Lasch: New York-based design research studio working across architecture, art, and computational design, with a focus on modular and parametric systems. Comparable in its small, research-driven studio model and its use of computational design to create collectible architectural objects.
• Studio Drift: Amsterdam-based art and design studio that fuses technology, nature, and craftsmanship to create experiential installations and objects. Comparable in its use of biomimicry, computational design, and material innovation for high-end experiential commissions.

Broad incumbents

• Snøhetta: Multidisciplinary design firm spanning architecture, interiors, landscape, and brand design with global projects in cultural, hospitality, and public sectors. Comparable to External Reference in experiential positioning and computational design ethos, but at significantly larger scale and broader scope.
• Zaha Hadid Architects: London-based global architecture firm known for computational and parametric design across cultural, hospitality, and retail projects. Comparable in its use of advanced digital tools for experiential architecture, though operating at much larger scale and brand recognition.

Emerging players

• Barkow Leibinger: Berlin- and New York-based architecture practice combining computational design, digital fabrication, and innovative materials in cultural and commercial projects. Comparable in scale, experimental fabrication approach, and focus on integrating technology with craft.
• Theverymany: Miami-based design studio led by Marc Fornes focused entirely on computational/parametric architecture and large-scale installations. Comparable as a small, research-driven studio using code-driven design and digital fabrication for experiential commissions.
• Random International: London-based contemporary art and design studio known for large-scale immersive installations blending technology and nature. Comparable in its focus on experiential, technology-driven installations for premium cultural and commercial clients, though weighted more toward art than architecture.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• Instagraminstagram.com/externalreference/?hl=en
• Xx.com/XRefArchitects
• Facebookfacebook.com/Externalreference
• LinkedInlinkedin.com/company/external-reference

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

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 External Reference