To a consumer there is little difference between a Fensa certified installer and a Certass certified installer. Both schemes are Government backed providing a alternative to submitting a building notice or using an approved Local Authority inspector for certain home improvements and building works.
All registered contractors to either Fensa or Certass are vetted to ensure they are qualified to carry out installation work in accordance with the current building regulations and, once an installation is complete, Fensa or Certass provides you with the Building Regulation Compliance Certificate for the work carried out.
All work carried out will also carry a insurance backed guarantee so should your contractors business close down your guarantee will still be honoured by the relevant scheme.
Which should you chose?
Basically either, you can check your installer is actually a member of either scheme by visiting the schemes websites using the links below.