What is BS 8414 Large-Scale System Testing?

  • Est Time: 20 mins

Read our blog below and watch the video above to learn more about BS 8414 Large-Scale System Testing, don't forget to test you've understood everything by taking the short quiz afterwards.

What is BS 8414?

BS 8414 is a large-scale system test that mimics a fire breaking out of a window and exposing a cladding system to a severe fire. 

The 60 minute test measures and evaluates fire spread and mechanical performance, and includes a 30 minute observation to evaluate propagation behaviour post exposure.

How does Combustibility affect BS 8414 Results?

We explored whether the outcome of BS 8414 large-scale system testing is affected by the combustibility of the insulation used in the cladding system - and directly compared two tests using insulation materials classified as 'non-combustible' and 'combustible'. Both systems met the rigorous requirements of this test.


What is BR 135?

Performance criteria for assessing cladding systems tested using BS 8414 is contained within BR 135 -  Fire performance of external thermal insulation for walls of multi-storey buildings. It is important to note that the classification applies solely to the specific external facade system which has been tested.
The BRE holds a public register of BR 135 classified external cladding systems completed at their test lab.

You can also download the full testing standard from the British Standards Institution shop:

Is BS 8414 still applicable?

In England, buildings with a storey at least 18m above ground level which fall outside the scope of the ban may still use external cladding systems that have passed the requirements of BR 135 when tested to BS 8414.

In Scotland, BS 8414 is recognised as an alternative route to compliance for external wall cladding systems having a European classification of A1 or A2 for all buildings with a storey at a height of more than 11m, as well as any assembly and entertainment, hospital and residential care buildings of any height. 

On 19th December 2019, the Welsh Government confirmed a ban on combustible materials on certain high-rise buildings from 13th January 2020.

Learn more about the recent amendments to Building Regulations.

What is BS 9414?


In addition to BS 8414, the British Standards Institute (BSi) has, as part of their fire safety commitment and as a request from the MHCLG, drafted a new standard for extended application - BS 9414.

The standard provides guidelines on what variations are possible to cladding systems tested in line with the existing BS 8414 standards.

Extended application enables a prediction to be made on the expected fire performance of a system under specified fire conditions if one or more the components or parameters which had been evaluated as part of the test specimen were to be changed. In the specific case of external cladding systems, such predictions are based upon the need to abide strictly with the fundamental principle that the fire performance of the modified system would be equal or better if it were to be subjected to a BS 8414-1 or BS 8414-2 test.

The BS 9414 standard covers insulated and ventilated rainscreen systems, external thermal insulated composite systems and self-supporting double skin metal faced insulated sandwich panels. It is specifically referenced in section 2 of the updated Scottish Technical Handbook.


Kingspan BS 8414 tested systems

Various products from our standard insulation, insulated panel and rainscreen facade ranges have met the requirements of BR 135 when tested to BS 8414 in specific system configurations. We publish all reports (both pass and fail).

Click here for more information, including specification details and downloadable classification reports.