What this effectively means is that under the new requirements of TGD B, at least two additional smoke or heat detectors must be installed in dwelling houses, with a heat detector in the kitchen and a smoke or heat detector in the main living room. Under the previous TGD B, the minimum requirement was for smoke detectors to be installed only in the circulation areas of a dwelling house (Category LD3).
In addition, these four alarms must be Grade D (mains powered with battery back up) and interconnected to each other.
Therefore, under the new requirements of TGD B this now means that four interconnected Grade D smoke or heat alarms must now be installed in an average dwelling house, compared to two under the previous TGD B.
The new requirements of TGD B will be required in new dwellings commencing on or after 1 June 2006. However, as is the case with all new Building Regulation requirements the operative date is subject to the transitional arrangements to allow the industry time to adjust to the new regime. In this case there is an exemption from the 1 June deadline for new buildings for which planning permission is applied for on or before 31 May 2006 and which are substantially complete by 31 May 2009.
This transitional arrangement is designed to avoid delays in the commencement of work on new buildings, at an advanced stage of design and planning.
Contractors should certify their installations using the model certificate form on page 67 of BS5839 Part 6.