Water-filled Glass

What Water-filled Glass does

Water-filled Glass Ltd is a UK-based building-technology company founded around 2010-2011 that develops water-filled glazing systems (WFG) for commercial and residential building envelopes. Its core technology replaces the air or gas fill in conventional glazing with a sealed water layer that absorbs incoming solar radiation (rather than blocking it via insulation or reflection), stores the captured thermal energy, and routes it to a building's mechanical system — effectively converting windows into solar collectors and thermal-mass regulators. The platform comprises five configurable variants (WFG-Basic, WFG-Storage, WFG-Advanced, WFG-Premium, and WFG-Exchange) plus a dedicated retrofit solution installed behind existing facades, allowing the same core IP to address conservatories, garden rooms, energy retrofits, and new high-performance commercial or residential construction.

The company operates a capital-light IP-licensing and project-based model: it does not manufacture glass itself but licenses its proprietary know-how to established construction firms and glass manufacturers, while also engaging directly with project clients for configuration, integration, and commissioning. Reported outcomes include 47-72% energy savings versus double glazing and 34-61% versus triple glazing, 66 kg CO2 saved per m2 per year versus double glazing, and a carbon payback as low as 1.5 years. Commercial sales began in 2023 in collaboration with industrial partners, with named reference projects in Hungary and Taiwan and stated deployment with clients in the US and Europe. The team is small (1-10 employees), founder-led by Dr Matyas Gutai, and has accumulated peer-reviewed publications in Energy and Buildings, Applied Energy, and the Journal of Facade Design and Engineering, alongside media coverage and a featured installation at the Venice Architecture Biennale 2025 in collaboration with Wicona (Hydro Building Systems).

Name

Water-filled Glass

Legal name

Water-filled Glass

Website

https://waterfilledglass.com

Company type

Private

Founded year

2010

Operating status

Operating

Headcount range

1–10 employees

Short description

Water-filled Glass develops water-filled glazing systems that absorb and reuse solar heat, licensing its IP to construction firms and glass manufacturers for newbuild and retrofit projects in the US and Europe.

Ownership category

akta.pro rank

Product category

Energy-Efficient Glazing

NAICS

Glass Product Manufacturing Made of Purchased Glass (327215), Flat Glass Manufacturing (327211), Glass and Glass Product Manufacturing (32721)

SIC

Flat Glass (3211), Glass Products, Made Of Purchased Glass (3231)

akta.pro primary industry

Insulating Glass Units (IGUs) & Double/Triple Glazing (IMADAHAC)

akta.pro secondary industries

Low‑E, Solar Control & Energy-Efficient Coated Glass (IMADAHAF), Skylights, Roof Glazing & Glass Roofing Systems (IMADAHAK), Tempered & Heat-Strengthened Safety Glass (IMADAHAD)

Keywords

• Water-filled glazing
• Energy-efficient windows
• Building envelope systems
• Solar thermal glass
• Thermal mass glazing

Headquarters

HQ city

Aldridge

HQ country

United Kingdom

HQ region

Europe

Markets served

GTM type

B2B

Offering type

Services

Cost components

Technology or R&D, Personnel, Marketing or Sales, Operations, Others

Revenue model

1. IP Licensing: Water-filled Glass licenses the use of its intellectual property to well-established construction firms and glass manufacturers. The company is not a glass manufacturer itself but provides the proprietary WFG technology and know-how to industrial partners who manufacture and install the glass panels.
2. Project-based Sales: The company directly engages with clients on specific projects, working with them to determine the appropriate WFG configuration. The company notes no project is too small or too big, indicating a flexible project-based engagement model.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels8 records

Core offering

Water-filled Glass develops and licenses Water-filled Glass (WFG) technology — glazing systems with encapsulated water that absorbs solar heat, functions as a solar collector, and provides thermal mass for buildings. The technology is offered in multiple engineering configurations (Basic, Storage, Advanced with ground pipes, Premium with heat pump, and Exchange inter-panel loop) and is delivered to construction firms, glass manufacturers, building developers, and retrofit customers. The company supplies both new-build installations and retrofit solutions, with pricing positioned as comparable to triple glazing.

Product overview

Water-filled Glass (WFG) is a unified glass technology platform that replaces standard glazing with water-filled panels. The core WFG product uses a water layer to absorb and manage solar thermal energy, functioning as both a passive cooling system in summer and a solar collector in winter. The platform includes multiple product variants: WFG-Basic (standalone thermal mass), WFG-Storage (with thermal storage), WFG-Advanced (with ground-source pipes), WFG-Premium (with heat pump integration), and WFG-Exchange (for heat redistribution between spaces). These variants can be combined (e.g., WFG-SAP) for maximized performance. A dedicated Retrofit Solution enables installation behind existing facades from the interior.

Differentiator

Problem solved

Functional benefit

Products and services

• Water-filled Glass (WFG) The flagship water-filled glazing technology — glass panels with encapsulated water that absorbs solar heat, functions as a solar collector, and provides thermal mass — sold to construction firms, glass manufacturers, building developers, and building owners for new construction and retrofit projects.
• WFG-Basic (WFG-B) Basic WFG installation where panels are deployed without connections to the mechanical system — a cost-effective configuration for projects seeking solar absorption and thermal mass without integrated heating/cooling infrastructure.
• WFG-Storage (WFG-S) WFG panels connected to a thermal storage unit, allowing absorbed solar heat to be stored and redistributed on demand for enhanced thermal management of the building.
• WFG-Advanced (WFG-A) WFG-Advanced configuration uses underground pipes to pre-heat or pre-cool water in the glass panels, leveraging ground-source temperatures for improved heating and cooling performance.
• WFG-Premium (WFG-P) WFG-Premium utilizes a heat pump to maintain water temperature in the glass panels, delivering optimized heating and cooling output for high-performance buildings.
• WFG-Exchange (WFG-E) WFG-Exchange is a special configuration where panels in spaces with different heating/cooling demands are connected via a water loop, enabling heat redistribution between zones for balanced thermal performance.
• WFG Retrofit Solution A retrofit installation approach for conservatories, glass extensions, garden rooms, and existing buildings that installs WFG from the inside, eliminating the need for external scaffolding and planning permits.

Quantifiable outcome

• Energy savings of 60-75% in associated energy costs (heating and cooling) compared to standard double glazing
• +4 more outcomes

Named customers2 records

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature11 records

Partnerships

Three partnerships are on record, tiered core.

• Wicona (Hydro Building Systems)coreTechnology or Integration · 1 January 2025Wicona, a brand of Hydro Building Systems, collaborated with Water-filled Glass on the Wicona TE Motion NG facade project. This collaboration advanced facade technology by integrating WFG for superior energy efficiency and CO2 performance. Wicona and its suppliers were involved in the frame development for the WFG system, including the Pylon of Permanence installation at Venice Biennale 2025.
• Industrial Partners (Construction Firms and Glass Manufacturers)coreOEM/ Whitelabel/ Licensing PartnerWater-filled Glass licenses its IP to well-established construction firms and glass manufacturers. Although the glass technology is novel, standard manufacturing techniques, frames, and mechanical systems are used, enabling a straightforward supply process. The company collaborates with these partners for product development and market deployment.
• Facade BuilderscoreImplementation/ SI/ Consulting PartnerDaniel Gabor Schinagl collaborated closely with WFG's industrial partners including glass factories and facade builders between 2015-2020 to finalize the technology's product development. Facade builders are involved in the installation and integration of WFG systems.

Scale indicators6 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Guardian Glass: Guardian Glass is a major float glass manufacturer with energy-efficient products such as SunGuard and ClimaGuard — comparable as an established architectural glass supplier competing for energy-conscious commercial and residential projects.
• Saint-Gobain Glass: Saint-Gobain Glass produces a wide range of energy-efficient architectural glazing including low-E and vacuum-insulated glass — directly comparable as an established competitor in the high-performance glazing category where WFG competes.
• Pilkington (NSG Group): Pilkington is one of the world's largest flat glass manufacturers with extensive energy-efficient product lines including low-E and triple-glazed units — the primary incumbent WFG is positioned against in the architectural glazing market.
• SageGlass (Saint-Gobain): SageGlass, owned by Saint-Gobain, produces electrochromic smart glass that dynamically controls solar heat gain — competing for the same energy-efficient building envelope specifications that WFG targets, but as part of a much larger building products portfolio.
• AGC Glass Europe: AGC is a global glass manufacturer offering energy-efficient products including low-E coatings and vacuum-insulated glazing — comparable as a broad incumbent in the same high-performance architectural glazing category.

Emerging players

• SolarWindow Technologies: SolarWindow develops electricity-generating photovoltaic coatings for glass windows and facades — thematically comparable as an emerging building-integrated glazing technology combining solar energy capture with conventional window functionality.
• ClearVue Technologies: ClearVue Technologies produces building-integrated photovoltaic glazing that generates electricity while managing solar heat — comparable as an emerging technology player combining solar energy capture with architectural glazing, similar in concept to WFG's solar-collector function.
• Vitrocsa: Vitrocsa produces ultra-slim, high-performance minimal-frame glazing systems for premium architectural projects — comparable as a specialist player in design-forward, energy-efficient glazing targeting high-end architects, similar to WFG's positioning with top architectural practices.

Direct peers

• View, Inc. View develops smart dynamic glass that electronically tints to manage solar heat gain and daylight — a directly comparable approach to managing radiant heat through advanced glazing technology, targeting commercial real estate and energy-efficient buildings.

Regional players

• Internorm: Internorm is a European manufacturer specializing in high-performance triple- and quadruple-glazed windows and doors — directly comparable as a specialist in premium energy-efficient glazing for residential and light commercial buildings, primarily serving the European market where WFG is also active.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/playlist?list=PL04M6Y2n1GvNNkRLT6Dilu9tFDiynhb05
• Facebookfacebook.com/WFGLtd
• LinkedInlinkedin.com/company/waterfilledglass
• Instagraminstagram.com/wfg_ltd

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

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 Water-filled Glass