Above ground drainage performance specification

On traditional mass housing construction projects in the UK the above ground drainage can be a simple affair and is often undertaken by the contractor’s mechanical subcontractor directly.

The situation is completely different on one off bespoke new houses or refurbishments. Most houses we work on are grade 1 or 2 listed and changes to the fabric to enable new drainage facilities for clients need to be carefully coordinated. We recommend that an above ground performance specification is produced for all projects, as it is critical to setting out the standards and specific requirements.


So what is above ground drainage?

As suggested it is the design of the drainage (or plumbing) above the ground. Therefore, on the interior of the building – usually from a basement or ground floor slab, whichever is lower.

The drainage works need to be fully designed to the British/European standards.


Do I need the above ground drainage designed?

In the UK the above ground drainage needs to be designed in accordance with the British/European standards and to comply with the Building Regulations. Its a common requirement across the world. We commonly come across projects where its not clear any design has been done. Unfortunately it is only after the project is complete and the building becomes occupied, that the problems become apparent. They are then far more expensive and disruptive to fix.

If the above ground drainage is not designed, what’s the problem?

If the specification and designs of the above ground drainage is not done, or correct, the following can and do occur frequently:

  • Wrong pipe materials used incorrectly.
  • Blockages due to inadequate falls.
  • Excessive drainage noise in rooms during discharge
  • Excessive boxing and reduced usable space (a big issue in London etc)
  • Air locking, gurgling and other air pressure problems
  • Release of sewerage smells into rooms.
  • Leaks

An even bigger problem is that you may only find you have a problem after all the interior work is complete and client using the facility. It will then be very disruptive and expensive for a client to have corrected. Avoiding professional design and specification is a large risk to take.

So what clients do you do this work for?

A wide range of clients, but usually with construction budgets in excessive of a million pounds. We work with leading Interior Designers, Architects and M&E specialists on domestic projects in London and the Home Counties, for UK and foreign multimillionaires. For confidentially reasonable we are unable to name such clients.