Editing Smoke detector (section)

=== Installation and placement ===
[[File:SmokeAlarmPlacement.svg|thumb|A 2007 U.S. guide to placing smoke detectors, suggesting that one be placed on every floor of a building, and in each bedroom]]

In the United States most [[U.S. state|state]] and [[Local government|local]] [[laws]] regarding the required number and placement of smoke detectors are based upon standards established in [[National Fire Protection Association|NFPA]] 72, National Fire Alarm and Signaling Code.<ref name=nfpa72>{{cite act|title=NFPA 72|number=72-2013|language=en|year=2013|url=http://www.nfpa.org/Assets/files/AboutTheCodes/72/72-13ROPDraft.pdf|access-date=6 August 2014|url-status=live|archive-url=https://web.archive.org/web/20140922234529/http://www.nfpa.org/Assets/files/AboutTheCodes/72/72-13ROPDraft.pdf|archive-date=22 September 2014}}</ref> Laws governing the installation of smoke detectors vary depending on the locality. However, some rules and guidelines for existing homes are relatively consistent throughout the developed world. For example, Canada and Australia require a building to have a working smoke detector on every level. The United States NFPA code, cited earlier, requires smoke detectors on every habitable level and within the vicinity of all bedrooms. Habitable levels include attics that are tall enough to allow access.<ref name=nfpa72/> Many other countries have comparable requirements.

In new construction, minimum requirements are typically more stringent. For example, all smoke detectors must be hooked directly to the [[electrical wiring]], be interconnected and have a [[battery backup]]. In addition, typically, smoke detectors are required either inside or outside every [[bedroom]], depending on local codes. Smoke detectors on the outside will detect fires more quickly, assuming the fire does not begin in the bedroom, but the sound of the alarm will be reduced and may not wake some people. Some areas also require smoke detectors in [[stairway]]s, main [[hallway]]s and [[garage (house)|garages]].<ref name="rcahw">{{cite book|last=Fletcher|first=Gregory|date=18 May 2011|title=Residential Construction Academy: House Wiring|url=https://books.google.com/books?id=ugOkSeJlfisC&q=placing+smoke+detectors|publisher=Technology & Engineering|isbn=978-1-111-30621-2|access-date=24 November 2014|url-status=live|archive-url=https://web.archive.org/web/20180508184806/https://books.google.com/books?id=ugOkSeJlfisC&dq=placing+smoke+detectors&source=gbs_navlinks_s|archive-date=8 May 2018}}</ref>

A dozen or more detectors may be connected via wiring or wirelessly such that if one detects smoke, the alarms will sound on all the detectors in the network, improving the likelihood that occupants will be alerted even if smoke is detected far from their location. Wired interconnection is more practical in new construction than for existing buildings.

In the UK, the installation of smoke alarms in new builds must comply with British Standard BS5839 pt6. BS 5839: Pt.6: 2004, which recommends that a new-build property consisting of no more than 3 floors (less than 200 square metres per floor) should be fitted with a Grade D, LD2 system. Building Regulations in England, Wales and Scotland recommend that BS 5839: Pt.6 should be followed, but as a minimum a Grade D, LD3 system should be installed. Building Regulations in Northern Ireland require a Grade D, LD2 system to be installed, with smoke alarms fitted in the escape routes and the main living room and a heat alarm in the kitchen; this standard also requires all detectors to have a mains supply and a battery backup.<ref>{{cite act|title=BS 5839-6:2013 Fire detection and fire alarm systems for buildings - Code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises|number=5839-6|language=en-GB|year=2013|url=http://www.safelincs.co.uk/pages/bs5839-6.html|access-date=24 November 2014|url-status=live|archive-url=https://web.archive.org/web/20141202161054/http://www.safelincs.co.uk/pages/bs5839-6.html|archive-date=2 December 2014}}</ref>