Loft Conversion Building Regulation information
At Regency we will take care of all of the necessary requirements to conform to all building regulations when planning your loft conversion.
The following information is intended to provide advice on a particular aspect of the regulations ie loft conversion. It is not a statement of law but is intended to help you understand the system. For further information you can contact Regency Loft Conversions or your local building control office.
This information covers the conversion of lofts within single occupancy bungalows and two story houses, and should not be applied to loft conversions within flats, maisonettes and houses in multiple occupancy, houses of more than two storey or non residential property.
Regency offers professional advice to ensure the loft conversion to be carried out complies with current regulations. The building regulation application is carried out by Regency qualified architects and structural engineers.
See below for more information on building control specifications & guidance.
Your loft may be very spacious or very small dependent on your existing roof construction. It may be a modern truss rafter design comprising of many timber sections or a traditional design with large timber purlins and rafters. Regency loft conversions will advise which braces in a traditional construction are merely construction aids or essential supports to the overall structure.
Whatever the nature of your roof , if it is intended to make alterations to the roof structure to form either dormers or roof lights it will be necessary for Regency to demonstrate to the local authority how the roof loads are effected, redistributed and supported.
Thermal insulation must be provided to the walls and ceilings pf the new rooms. The insulation must not obstruct any newly created air paths that are provided to reduce the possibility of interstitial condensation within the roof void. This is a critical part of the regulations often misunderstood and overlooked by the less experienced.
The existing ceiling joists are highly unlikely to have the capacity to carry the addition loads of the new domestic floor. The ceiling joists are in most cases unable to carry their own load therefore requiring suspension timbers via the purlins or rafters. The new floor must be supported at the ends on load bearing walls or beams calculated to accept the floor loads. Joists sizes are dependent on the spans involved.
The practice of laying boards on the existing ceiling joist is not recommended. Future owners may unwittingly consider the floor to be substantial. This will lead to serious damage to the ceilings or possible collapse. The lath and plaster system will not tolerate the continuous vibrations of a domestic load therefore large sections of heavy plaster eventually drop off the ceilings. A new calculated floor is independent of the existing ceilings.
The new loft floor in a three storey dwelling or over a garage will have to resist the effects of fire and smoke penetration for half an hour. This will assist you or your family to escape safely or to remain in the room until the arrival of the emergency services. Acoustic insulation blankets are installed in all cases.
The walls on which any new wall or floor resides must be load bearing. Load bearing means to have the capacity to carry the new weight eventually leading to a concrete or stone foundation. This aspect is critical to ensure local authority approval.
In all dwellings other than existing bungalows the new room must be separated from the rest of the house by a half hour fire resistant partition and self-closing fire door. The fire door to the new room may be positioned at the top or the bottom of the new stairway.
The existing walls around the existing stairs should have a minimum of half hour fire resistance.
Glazing in any existing walls or doors around the stairwell must be eliminated or replaced with fire retardant glass.
The new dormer walls must be treated with a weather resistant finish and provided with thermal insulation. If a wall to a dormer is within 1m of the boundary to a neighbouring property it will be necessary to provide fire protection to the wall from the inside and outside.
Acoustic insulation blanket installed in all internal dividing partitions.
To gain access to a room you will need to consider the type of stair you would like. Loft ladders are not permitted to any habitable rooms.
The preferred type of stair is a traditional type with landings top and bottom with equally sized steps. Space saver and spiral are permitted in certain circumstances. In all cases suitable guarding and handrails must be provided and good headroom of not less than2m must be provided. The headroom requirement is a vertical measurement. A relaxation down to 1.8m will in certain circumstances be acceptable.
In a house, if the new staircase is constructed off a floor over a lounge or other habitable room it will be necessary to upgrade the fire resistance of the existing floor to half an hour. It is cost effective to ensure that the new staircase rises within the existing staircase enclosure wherever possible. On inspection we will advise whether it is possible or not to install the staircase off the existing landing.
A staircase fitted or located incorrectly will actually de value a property in most cases.
This is described as the unaided evacuation of the building by the occupants and is provided principally by the stairway. The staircase at ground level must discharge to a final exit, normally the front or back door.
Recent regulations stipulate that if a new stairway discharges to the ground floor whether in a hall or room with a final exit door an escape window must be installed in all new habitable rooms at 1st floor level.
From July 2010 the guidance in the Approved document Part B-Fire Safety recommends provision of fire detection and alarm systems and that escape stairs should be protected by fire resisting construction and doors (which need not be fitted with self-closing devices). There is no-longer a reliance on suitably positioned egress windows from 2nd floor loft rooms as alternative means of escape. In most cases the local authority will accept smoke alarms in all habitable rooms including landing areas..
If the loft conversion involves a new second storey exceeding 50m square in floor area or the new second storey contains more than two habitable rooms, additional fire requirements apply.
SMOKE ALARMS – HEAT DETECTION SYSTEM
Electrical Fire Alarm System to be Part 6 – LD2. Every habitable room to have mains interlinked smoke detectors with a heat detector within the Kitchen. Smoke detectors installed at ground & first floor in hall & landing, both detectors to be permanently wired in on a separately fused circuit with a secondary battery backup. Where more than one smoke alarm is installed they should be linked so that the detection of smoke by one unit operates the alarm signal in all of them. The manufacturers instructions about the maximum number of units that can be linked should be observed. Alarms to be positioned 7m max from kitchen or lounge doors & max 3m from bedroom doors, minimum 300mm from any wall or light fitting. Where a kitchen is not separated from the stairway or circulation space by a door, there should be a compatible interlinked heat detector or heat alarm in the kitchen in addition to whatever smoke alarms have been Specified. BCO to confirm with contractor on-site.