Passivhaus Affiliate

Passivhaus Retrofit

EnerPHitPassivhaus is not just for new builds. Through a focus detailed planning paired with quality building components, superior insulation, ventilation with heat recovery, thermal bridge free design and airtight construction, deep energy retrofits can be achieved using the Passivhaus Standard.

EnerPHit is a slightly relaxed standard for retrofit projects, where the existing architecture and conservation issues mean that meeting the Passivhaus standard is not feasible, due in large part to unavoidable thermal bridges in the existing structure. The EnerPHit standard recognises the constraints imposed by working with an existing building and has been created with lowered airtightness and heating demand criteria specifically for these reasons.  An introduction to the standard can be found on What is Passivhaus.


PHT retrofit policy statement

In 2016, along with supporting the Nearly Zero Energy Buildings (NZEB) target for new build housing developed as part of the Energy Performance in Buildings Directive, the Passivhaus Trust campaigned that the UK Government should support deep energy retrofit projects by recognising and adopting the EnerPHit Standard as an exemplary refurbishment target, and help to inform better practices and methodologies.

Passivhaus Retrofit policy

A whole house retrofit approach is not always viable immediately. The EnerPHit standard can also be implemented via a phased strategy which includes intermediate certification. Best practice guidance on this approach is currently being produced via the EuroPHit projectWilmcote House (see below case studies) is a UK case study participating in this European project.

 Step by step retrofit with certified Passivhaus components   Implementing deep energy step by step retrofits

Useful lessons could be drawn from 25 years of Passivhaus experience and testing, to help during the implementation phase of the Every Home Counts report. The Trust are involved in an implementation workstream striving to promote deep energy retrofits with EnerPHit as a target. 

Passivhaus step by step retrofit


Case studies

Ernerley Close

Cedar Court

Gandy’s Croft

Wilmcote House

Ernely Close Cedar Court OWLS Wilmcote House


  • Social Housing

  • Manchester

Refurbishment of a block of flats plus neighbourhood regeneration for One Manchester HA. Complete & occupied.


  • Social Housing

  • Glasgow

Refurbishment of a tower block for Glasgow HA, plus local regeneration. Under Construction.(presentation here)


  • Social Housing

  • Solihull

Solihull Community Housing OWLS (Off-site Wrap-around Large Scale) retrofit project (more here


  • Social Housing

  • Portsmouth

Portsmouth City Council's step by step refurbishment of a tower block with residents insitu. Part of the EuroPHit scheme. Currently on site.

Hiley Road

Passmore Street

Cre8 Barn

Admirals Hard

Hiley Road  Passmore Street Cre8 Barn  Admirals Hard
  • Private Residential
  • London

Retrofit of a victorian terrace to Passivhaus Standard. Complete & occupied. (presentation here)

  • Private Residential
  • London

Grosvenor EnerPHit refurbishment of a historic grade II listed terrace that is privately rented.

  • Educational/Community 
  • Huddersfield

Box within a box’ structure (inner timber frame within outer masonry barn) which has transformed a derelict cow byre into a flexible, all-purpose educational centre 

  • Office 
  • Plymouth

Conversion of a first floor flat into an EnerPHit office, and extensive retrofit of the whole building, which includes  a ground floor shop. 

Bonfield Review

The Bonfield Review, titled ‘Each home counts’, was published at the end of 2016 and summarizes that there is a need for greater consumer protection related to energy efficient retrofit measures and renewable energy through a new framework and quality mark.

The Trust welcomes recommendations on conducting thorough assessments of each property prior to retrofit, as well as recognizing the need for robust monitoring. The Passivhaus approach already addresses many of the points raised in the report:

  • Approved Certification Body – the Passivhaus Institut and approved trained certifiers
  • Codes of Practice and Standards – an existing, deep retrofit standard (EnerPHit)
  • Training in core knowledge about building physics, design and consumer interaction – Chartered European Passivhaus (CEPH) Designer training
  • A system for Quality Control and Enforcement – Passivhaus certification

Further Information


Previous PHT story: Bonfield Review: A step in the right direction? – 27 February 2017