Certification
Passivhaus
We collaborate with architects, developers, contractors, and local authorities on new-build and EnerPHit projects across the residential and commercial sectors, supporting them throughout the entire Passivhaus certification process, from early-stage design to final onsite verification.
Passivhaus Classic, Plus and Premium certification
EnerPHit for renovation and historic buildings
Official Passivhaus certificate issued by approved body
Extensive international experience since 2010
Leaders in certification of educational and office buildings

Consultancy
What is the reliable partner
Passivhaus Certification is an independent quality assurance process that ensures a building meets the rigorous performance requirements of the Passivhaus Institute (PHI).

Guaranteeing:
- Extremely low energy consumption
Thermal comfort and indoor air quality
Absence of condensation and mould
Healthy environments with a high level of soundproofing
High quality construction

The process evaluates:
Energy demand
Air tightness of the enclosure (n50)
Thermal performance of the envelope
Ventilation design and performance
Limits the risk of overheating

Our Role
We assist the client with technical or economic feasibility studies
We provide support to the design team
We verify the work of the Passivhaus consultancy. We offer on-site support to the construction company.
Apoyo, revisión y control en obra para garantizar la obtención de la certificación Passivhaus.
Benefits
Types of certification Passivhaus

Passivhaus Classic, plus and premium
Passivhaus EnerPhit Certification
Passivhaus LEB certification
Otras certificaciones de sostenibilidad
Clients
With who work with
Architects

Engineers

Construction companies

Local Authorities & Public Sector

Demanding developers

ZEPASSIV
Our dedicated consultancy services
Preliminary analysis and technical feasibility
Support for Passivhaus Designers
On-site inspection
Blower door test (Blower Door)
Final certification
Follow
ZEPASSIV
Why choose Zepassiv?
International experience in Passivhaus projects and high efficiency buildings
More than two decades working in Spain, UK and Portugal, with residential, public and private projects.
Passivhaus, EnerPHit and energy efficiency certified consultants
Multidisciplinary team proficient in PHPP, WUFI, Flixo/IES VE, TM59, comfort analysis and building physics.
Fully collaborative approach
We work side by side with architects, engineering and construction companies, facilitating technical decisions in all phases of the project and assisting on site.
Risk reduction by design
We identify thermal bridges, damp, overheating and construction problems before they appear on site.
Cost and performance optimisation
We propose viable, efficient solutions aligned with energy objectives, regulations and certification (Passivhaus, EnerPHit, AECB, Net Zero).
Servicio multilingüe
We facilitate communication in international teams or cross-border projects. Zepassiv is active in 15 countries.
Testimonials
What they say our clients
Excellent certification service. They were very helpful and informative throughout the process.
Passive House Home Owner
UKPassivhaus Certifier with extensive practical experience, able to support the project from early engagement all the way to the end of it.
Lucia Savastano, Cundall
UKI chose Zero Energy + Passive to certify my house with the Passive House Standard, and the experience exceeded all expectations! Being their first project in Portugal, they delivered incredible service—they are fast, accurate, reachable and always constructive. Thanks to their expertise and dedication, we achieved the Passive House Plus certification, an amazing milestone that I'm extremely proud of. I highly recommend Zero Energy + Passive to anyone looking for excellence in Passive House certification!
Passivhaus Plus Home Owner
Portugal
FAQs
Frequent questions
Does Zepassiv issue certificates outside UK?
Yes: we provide certification services worldwide, with projects in the United Kingdom, Ireland, Portugal, Chile, Mexico, Australia and the Middle East.
Is a leak test mandatory?
Yes, it is an essential requirement for obtaining the certificate.
What does a Passivhaus inspector do?
It carries out thorough reviews during the design phase and on-site inspections, gathers evidence and ensures the quality of the construction work.
What is a Passivhaus certifier?
A highly qualified professional who checks and verifies that the project meets the standard and issues the final certificate on behalf of the Passive House Institute.











