Appropriate Guarantees

Appropriate Guarantees2021-03-03T18:25:11+00:00

Fig 1. EWI Fire Damage

Fig 2. EWI Cladding Collapse

Fig 3. EWI Render Cracking & Black Mould

ECO3 appropriate guarantees, Ofgem, TrustMark; external wall insulation, EWI, fire damage, cladding collapse, render cracking and black mould; cavity wall insulation, CWI, damp and mould, flood water risk and electrics; SWIGA, CIGA, Kinnell, GDGC/Qualitymark Protection, The Insulation Assurance Authority (IAA) Ltd; defects investigations.

There are now increasing reports in the media and elsewhere of external wall insulation system fires, render and brick-slip finishes falling from buildings, excessive unsightly black mould on external render finishes, water penetration, damp and mould on internal plaster finishes and, in the case of cavity wall insulation, installation of inappropriate cavity wall insulation measures unsuited to the vagaries of the house construction, ingress of wind driven rain, flood water penetration, black mould, etc.

The damage caused by water penetration, as opposed to condensation, and consequent mould is now a major problem for thousands of homeowners throughout the country. Cold wet walls transmit more heat to the outside and result in increased heating bills. The mould is unsightly, gives off an unpleasant smell, and contaminates clothes, furnishings, decorations and carpets; and when black mould takes hold, even in small concentrations it is a serious health risk which can significantly increase the risk of respiratory illnesses in some people and result in asthma, bronchial complaints and other upper respiratory diseases.


There are also reports of homes which have insufficient cavity insulation or voids within the cavity insulation in the walls, and older properties with unsuitable narrow width cavities or stone built uneven width cavities (including through stone ties) which are particularly susceptible to both condensation and rain water penetration problems and outwith of independent third-party Certification for the  installed cavity insulation measure and should not have been insulated with inappropriate cavity wall insulation measures.

Fig 4. CWI Damp & Mould

Fig 5. CWI Flood Water & Electrics

Fig 6. Damp and Black Mould

Homeowners whose properties have been affected should check their external wall insulation appropriate guarantee (for example, Solid Wall Insulation Guarantee Agency, SWIGA) or cavity wall insulation appropriate guarantee (for example, Cavity Wall Insulation Guarantee Agency, CIGA) respectively, relevant insulation measure independent third-party Certification, and home insurance policies and, where appropriate, request an inspection survey of their properties.

Cavity wall insulation, external wall insulation (also known as solid wall insulation) and park home insulation systems have respective standard lifetimes of 42, 36 and 30 years where an installation is accompanied by an appropriate guarantee.

An appropriate guarantee is one which meets all of the four criteria listed below:

  • Financial assurance: there must be a mechanism that gives assurance that funds will be available to honour the guarantee

  • Duration: lasts for 25 years or longer

  • Coverage: results in the failed measure being replaced and covers costs of remedial and replacement works plus materials, and

  • Quality Assurance Framework: there must be an assurance framework for the quality of the installation and the product used in the installation.

The current list of Energy Company Obligation ECO3 appropriate guarantees can now be found on the TrustMark website as Ofgem no longer administers appropriate guarantees or financial protection, and any queries regarding these should be directed to TrustMark.

All TrustMark Registered Businesses are required to provide their customers with the appropriate level of financial protection, and must include cover, but not limited to, the following:

  • Rectification of defects or major damage
  • Non-compliance with Building Regulations

It is now a mandatory requirement that all 25Year ECO measures are accompanied by an independent guarantee for the following:

  • External Wall Insulation (EWI)

  • Internal Wall Insulation (IWI)

  • Cavity Wall Insulation (CWI)

  • Hybrid Wall Insulation

  • Park Home Insulation

  • Room-in-Roof Insulation

  • Under Floor Insulation

Note: the reader is advised to check the current TrustMark listings of Approved Appropriate Guarantees and Approved Financial Protection Mechanisms. For details go to