Attic - Loft Conversion Guidelines
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from the Department of the
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Converting the roof space may be a convenient way of obtaining
additional living space in an existing dwelling house, without extending
into the garden. However there are many issues to be resolved before
any works are carried out. There is a legal requirement to comply with
building regulations, including those related to fire safety. The purpose
of these fire safety requirements is to safeguard you and your family,
should a fire occur in your home. This leaflet highlights the principal
fire safety issues that need to be considered when converting the roof
space (loft / attic) in an existing dwelling house.
Before deciding to carry out any works, an assessment of the feasibility of
achieving the required accommodation and complying with the statutory
requirements (including fire safety requirements) should be made.
You are recommended to get advice from a building professional
(e.g. Architect, Engineer) on the design of your attic / loft conversion, the
selection of a competent contractor, the supervision of the conversion work,
the certification of payment instalments to the builder, and the certification
of the completed conversion as being in compliance with applicable
planning / building regulations. Having compliance certification on file will
be helpful if you should decide to sell your house, at some future date.
Professional advice should, for example, help to ensure that primary access
to, and emergency exit from, the converted roof space is by means of
a secure stairway (not just pull down steps); and to identify / resolve any
important structural safety issues (e.g. structural strength of ceiling joists
to support flooring, any proposed adjustment of timber trusses supporting
roof). The extra cost of professional services should pay for itself by
helping to ensure that the conversion is up to standard and is safe
for you and your family.
FIRE SAFETY: THE LEGAL REQUIREMENTS
Part B of the Building Regulations sets out mandatory fire safety
requirements; and Technical Guidance Document B (TGD-B) shows
how to comply with Part B. TGD B can be accessed on the web at:
under the headings “What We Do”, “Building Standards”.
Alternatively, TGD B can be purchased from the
Government Publications Sales Office, Molesworth Street, Dublin 2.
This leaflet is not intended as an alternative to the relevant provisions
of Technical Guidance Document B.
An authorised officer of the local building control authority is entitled
to inspect works in connection with the conversion of a roof space
in a dwelling house, for the purpose of ensuring compliance with
When the roof space of a dwelling house is converted to living
accommodation, an additional storey is in effect added to the house.
This means that a bungalow becomes a two-storey house and a two-storey
house becomes a three-storey house.
Additional storey height increases the difficulty of escape should a fire
occur and the provisions required under the building regulations are
This is particularly the case for a three-storey house, where the existing
stairs and the new stairs should be enclosed in fire resisting construction.
This applies to the wall construction and the doors into the habitable rooms.
The technical guidance to the building regulations makes special
provisions for loft conversions in existing two-storey dwelling houses,
where the conversion provides not more than two habitable rooms and
the additional accommodation is less than 50m2. These relate to the means
of enclosing the stairs to the new storey and upgrading of the protection
to the existing stairway.
The habitable rooms in the new storey should each be provided with
a window or roof light that is suitable for escape or rescue. Guidance
is given on the dimensions for the size and position, relative to the eaves
and new floor level, for these windows / roof lights (roof windows).
CONVERTING EXISTING ROOF SPACE
OF TWO STOREY HOUSE IN TO
IF YOUR CONVERSION
• Doesn’t involve raising the roof-line above the existing ridge
• Is 50 square metres or less
• Has no more than two habitable rooms
• you may use these fire safety provisions.
1 Enclose the existing stairway with fire resisting Walls or partitions
2 Extend fire-resisting enclosure to a Final exit (such as the front door)
Give access to two escape routes at ground level, separated by
3 New stairs to comply with Building
Regulations guidance on stairways, including
Maximum 42 degree pitch
Minimum 220 mm going
Maximum 220 mm rise
Minimum 1900 mm headroom
Minimum 800 mm wide
Other guidance may be found in TGD to Part K
4 Separate the new accommodation from the existing stairway
4a Extend the existing enclosure up into the roof space and separate
the new rooms from the stairway in fire-resisting construction
4b If the new stairway rises in an existing room, separate it from the room and
from the rest of the house by fire-resisting construction and fire door at the top
or bottom of the new stairs
5 All new doors to habitable rooms to be self-closing fire doors
6 All glazing in the existing stairway enclosure is to be fixed shut and to
7a Separate the new storey from the rest of the house by “full 30 minute”
7b Ensure the existing first floor is of “modified 30 minute fire resisting standard”
8 Each new attic room to have a window or rooflight for escape or rescue. This means:
8a Unobstructed opening minimum 850 mm high and 500 mm wide
8b Any fastenings to be readily openable from the inside
8c Bottom of a window opening to be between 800 and 1100 mm above the floor
8d Bottom of a rooflight opening to be minimum 600 mm above the floor
8e From the eaves to the cill of a dormer window or rooflight the distance to be
maximum 1700 mm
8f ground under the window to be clear of any obstructions, to support a ladder safely,
to be big enough to provide a place of safety
8g Provide guarding around any balcony accessed by french window or patio door
9 Provide interconnected mains powered smoke alarms with battery back up
at all storey levels
FIRE DETECTION AND ALARM SYSTEMS
All new dwelling houses must be provided with fire detection and alarm
systems. When the roof space of an existing dwelling-house is converted
to create an additional storey, a fire detection and alarm system must be
provided in accordance with the requirements for a new dwelling house.
Where a loft / attic space has been converted, interconnected mains operated
self-contained fire alarm units (preferably with battery back-up power
supplies) must be provided within the stairs enclosure at ALL storey levels.
It should be noted that smoke alarms powered only by batteries
are not sufficient.
PROTECTION TO STRUCTURAL ELEMENTS
The building regulations impose requirements for fire resisting floor
construction to restrict the spread of fire between storeys and to
protect against premature collapse in the event of a fire.
A three-storey dwelling house has higher fire resistance requirements for
floors than a two-storey dwelling house. A loft / attic conversion in a twostorey
dwelling house adds an additional storey to the house and this has
implications for the existing first floor and the new second floor construction.
The floor to the new storey will be required to provide the fire resistance
requirements for a new three-storey dwelling house.
Special provisions apply to loft / attic conversions where not more than two
additional habitable rooms are provided and additional floor area is less
than 50m2. Where these apply, the existing first floor will normally provide
the necessary fire resistance, subject to assessment of the fire performance
of the actual construction.
Where the accommodation does not extend into the eaves of the roof, the
fire resisting floor construction should be carried through to the external walls.
Where a dwelling house is semi-detached or is part of a terrace of houses,
it is essential to ensure that the party wall between adjoining houses
continues to the roof level and the roof junction is adequately fire stopped.
There should be no gaps or imperfections in the party wall construction,
which would facilitate the spread of fire between houses.
Any new structural members such as floor beams or columns should
be provided with the required level of fire resistance.
It is very important that all electrical work is carried out by a qualified
Electrician, as improperly designed / installed fittings and inadequate
wiring can constitute a serious fire hazard.
Particular care is required with the design and installation
of recessed lighting systems.
This leaflet is intended to draw attention to the importance of properly
dealing with fire safety issues in attic / loft conversions, with the help of
professional advice. There are 11 other Parts of the Building Regulations,
which must be complied with, and which deal with issues other than
fire safety including:
• Part A - Structures
• Part D - Materials and Workmanship
• Part E - Sound Insulation
• Part F - Ventilation
• Part L - Conservation of Fuel and Energy, including thermal insulation
The relevant Technical Guidance Document, on how to comply with
Parts A - M inclusive, can be viewed on the Department’s website:
www.environ.ie “What we do” - “Building Standards” or purchased
from the Government’s Publications Sales Office, Sun Alliance House,
Molesworth St., Dublin 2 [Tel: 01 6476000].
HOUSES OF ARCHITECTURAL / HISTORIC IMPORTANCE
In the case of older houses, particularly those of architectural / historic importance
the applicationof the guidance set out in TGDB (Fire Safety) on Part B of the Building
Regulations will notalways be appropriate; and alternative approaches to meeting
the fire safety requirementsof the Building Regulations will need to be considered.
If your house is a protected structure(or a proposed protected structure), under the
Planning Act 2000, you may require planningpermission for an attic / loft conversion.
You, or your professional adviser, should contact theConservation Officer in the the
local planning authority, well in advance of designing or carrying out the works.