Bldg regulations on fire alarms

Hi. Can anyone tell me if it is a requirement to wire in a fire/smoke alarm in a new build or is it only advisable.

I never cleared this point with my builder and want to have an alarm installed. If it is not a requirement I will probably have to pay extra but would like to know the situation before broaching the subject.

Thanks in advance for any advice.

it is a building regulations that:

1.5.5.2 Fire detection and alarm system types

Dwelling houses should be provided with an LD1 or
an LD2 fire detection and alarm system in
accordance with BS 5839 Part 6: 2004 designed for
the protection of life.
An LD1 system incorporates suitably located and
interconnected detectors throughout the dwelling
house, including all circulation areas that form part of
the escape route and in all rooms and areas in which
a fire might start, other than toilets, bathrooms and
shower rooms.
An LD2 system incorporates suitably located and
interconnected detectors in all circulation areas that
form part of the escape route and in all rooms or
areas, such as kitchens and living rooms, that present
a high fire risk.
Heat detectors should be provided in kitchens.
Dwelling houses with up to three storeys above
ground level should have at least an LD2 system.
Dwelling houses with more than three storeys, large
houses, or where the fire risk so warrants, should be
provided with LD1 systems as appropriate, which
will provide a higher level of life safety. Guidance on
system types for different situations is contained in
BS 5839: Part 6: 2004.

basically... a fire detection and alarm system must be installed, and wired to the mains, and also have battery back up.....

Thanks for putting me straight on that Sydthebeat.