A Passivhaus consultant is a certified designer or adviser who helps projects design, model and achieve the Passivhaus standard of ultra-low energy performance. The Passivhaus standard originated in Germany and is now widely adopted in the UK for new builds and retrofit (EnerPHit) projects seeking the highest level of fabric energy efficiency. Certification requires formal energy modelling using PHPP (Passivhaus Planning Package) software, verified airtightness testing, and assessment by a certified Passivhaus certifier. Consultants typically hold PHI (Passivhaus Institut) Certified Passivhaus Designer (CPHD) qualification or APHA membership.
What they do
- PHPP (Passivhaus Planning Package) energy modelling
- Building fabric specification for certified performance
- Window, door and thermal bridge assessment and detailing
- Airtightness strategy and membrane specification
- MVHR specification and coordination
- Site orientation and solar gain optimisation
- Passivhaus certification management and liaison with certifier
- Training and design review for architects and contractors
When you need one
A Passivhaus consultant is needed on any project targeting Passivhaus or EnerPHit certification, or seeking to achieve near-Passivhaus fabric performance levels.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| PHPP modelling and design review | £2,000 - £6,000 |
| Full Passivhaus design service | £5,000 - £15,000+ |
| EnerPHit retrofit modelling | £3,000 - £8,000 |
| Passivhaus certification coordination | £1,000 - £3,000 |
| Airtightness testing and advice | £500 - £1,200 |
Costs depend on project size and complexity. Passivhaus design fees are offset by very significant reductions in energy bills over the building's lifetime. Always confirm the consultant holds current CPHD or APHA membership.
Qualifications to look for
The Certified Passivhaus Designer qualification from the Passivhaus Institut (Germany) is the internationally recognised standard for Passivhaus design competency. Holders are qualified to model, design and oversee Passivhaus certified buildings. Search the PHI database at passiv.de.
APHA is the UK professional body for Passivhaus practitioners. APHA membership indicates current engagement with the UK Passivhaus community and up-to-date knowledge of UK-specific applications of the standard.
Passivhaus consultants typically hold degrees in architecture, building services engineering or structural engineering as the foundation for their specialist Passivhaus training.
How to find a reputable Passivhaus consultant
Frequently asked questions
What is the Passivhaus standard?
Passivhaus is a German-originated performance standard requiring a heating demand below 15 kWh/m2/yr, total primary energy below 120 kWh/m2/yr, airtightness below 0.6 ACH at 50Pa, and thermal comfort in all rooms - achieved through super-insulation, thermal bridge-free construction, triple glazing, excellent airtightness and MVHR.
How much more does a Passivhaus cost to build?
Typically 5-15% more than a standard new build. The premium has reduced as the industry has gained experience. The higher capital cost is offset by dramatically lower running costs - typically £100-300/year for space heating.
What is EnerPHit?
The Passivhaus retrofit certification standard - with slightly relaxed targets to account for the challenges of working with existing buildings. It is the highest available retrofit energy standard in the UK.