Houses, Flats and Apartments

Due to their unique cellular structure, made up of thousands of non-connected cells, Celcon Blocks produce much better sound insulation than aggregate blocks of the same weight

There is no need for Pre-Completion Testing (PCT) to satisfy Part E of the Building Regulations for new build houses, flats and apartments. Robust Details ( provide standard specifications for a number of separating and flanking wall constructions using Celcon Blocks in houses, flats and apartments.

In order to be approved as a Robust Detail, each design must:

  • be capable of consistently exceeding the performance standards given in Approved Document E of the Building Regulations for England and Wales
  • be practical to build on site
  • be reasonably tolerant to workmanship

Robust Detail designs are pre-tested to higher standards than those required by Approved Document E. Therefore, if you register your build with RDL and build in compliance with Robust Details, pre-completion sound testing is not required.

Flats and apartments can be built using Celcon Blocks throughout.  Robust Details E-WM-6, E-WM-10, E-WM-13, E-WM-15, E-WM-23 and E-WM-24 for separating walls can be used for flats and apartments.  When used in conjunction with the Robust Detail separating floor solutions E-FC-4,5, 8 or 9, there is no need for PCT of the whole flat.


Building Regulations Approved Document E section 4 refers specifically to acoustic performance in schools and references Building Bulletin 93: Acoustic design of schools – performance standardsDue to the complexity of the design process, the document advises that “it is strongly recommended that the client require acoustic testing to be carried out as part of the building contract….In all but the simplest of project it is advisable to appoint a suitably qualified acoustic consultant at an early stage of the contract.”

A range of masonry solutions using H+H aircrete will satisfy the performance level required for schools and the H+H technical department will be able to provide specific further details.

Rooms for Residential purposes

H+H provides a number of solutions for separating and flanking walls in rooms for residential purposes (such as hotels and hostels). These buildings are subject to the requirements of Part E of the Building Regulations, but the use of Robust Details is not recognised as a suitable form of demonstrating compliance.  Consequently pre completion acoustic testing is required on site.