Opens in a new tab
  • Español
  • English
  • Português

Energy consultancy and Passivhaus design for high-efficiency buildings

We support architects, engineering firms, property developers and public authorities in the design of low-energy, Net Zero and Passivhaus-standard buildings through advanced simulations and building physics analysis.

  • Passivhaus modelling (PHPP)

  • Hygrothermal simulation (WUFI)

  • 2D &3D thermal bridge modelling

  • Overheating Risk Part O / TM59 / TM52

  • Envelope and energy efficiency consultancy

  • Airtightness strategy and zoning

Request
our consultancy services

PASSIVHAUS

What is included in our
energy consultancy

  • Passivhaus modelling and optimisation (PHPP)

    • DesignPH and PHPP

    • Energy balance and envelope optimisation

    • Shading & solar gain analysis

    • Airtightness strategy and zoning

    • Overheating risk assessment

  • Building Physics & Performance Simulation

    • Hygrothermal simulation (WUFI)

    • 2D and 3D thermal bridge modelling

    • Condensation & mould risk analysis

    • IES VE dynamic building simulation

  • Low-Energy & Net Zero Building Consultancy

    • Optimisation of construction solutions

    • Cooling strategies for hot climates

    • Expert reports and technical opinions for disputes and litigation.

    • 3D design and calculation of mechanical ventilation systems

    • Carbon footprints and LEED

PASSIVHAUS BENEFITS

Benefits of
our consultancy

  • Risk reduction in the design phase

  • Achieve Passivhaus & Net Zero standards

  • Improve comfort & minimise energy demand

  • Avoid costly changes on site

  • Expert technical team with +20 years of experience

    • Request
    our consultancy services

CLIENTS

Who do we
work with

  • Architects

  • Engineers

  • Construction companies

  • Local Authorities & Public Sector

  • Developers

ZEPASSIV

Our
process

Speak
to our experts

  • Initial analysis and feasibility studies

  • PHPP / WUFI / thermal bridges modelling

  • Technical workshop with the design team

  • Value engineering

  • Onsite
    support

  • Follow up

Request
technical consultancy

ZEPASSIV

Why work
with us?

  • 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).

  • Multilingual services

    We facilitate communication in international teams or cross-border projects. Zepassiv is active in 15 countries.

Portfolio

Some of our
recent projects

Find out how Zepassiv supports professionals in the
development of sustainable projects and Passivhaus-certified projects.

Passivhaus certified training to transform the sector

As certified consultants and trainers, we believe that training is key to driving real change. Our programmes help professionals to successfully apply Passivhaus principles to their projects.

Discover our training

Testimonials

What our clients say
about us

  • I was the client, and from the client's perspective, everything went very smoothly.

    Bill Haygarth- Homeower

    UK

  • Zero Energy has been a fantastic team to work with! They have provided extensive assistance in certifying our Passivhaus project and have been attentive throughout the entire process. We will definitely want to work with them again in the future at Clive Chapman Architects, and we highly recommend them to anyone who needs their services!

    Clive Chapman Architects

    UK

  • Amazing technology—it's hard to get it to work, but it's great when it does.

    Matthew Craig- Homeowner

    UK
  • Read more testimonials

FAQs

Frequently asked
questions

Yes. Consulting helps reduce energy consumption, improve comfort, and prevent construction defects, regardless of certification.

PHPP for energy modelling, WUFI for hygrothermal analysis, Flixo/THERM for thermal bridges, and TM59 for overheating.

Yes. We join your technical team to support the design and implementation.

Yes. We conduct technical site visits, verify details, and provide support for airtightness and quality strategies.

Yes, we also operate in Latin America.

This is a technical service that analyses a building’s energy, thermal, and hygrothermal performance, optimising its design, materials, and systems to meet high-efficiency standards.