Loft Conversion

If you need additional space in your home but you have no room to extend outwards, a loft conversion can be the perfect solution.

In most cases a loft conversion can be far less expensive than upgrading to a larger house and you won’t have the associated costs of moving.

But before deciding to convert your loft into additional living accommodation, you should give careful consideration to the following:

• Cost of loft conversions
• Planning Permission and Building Regulations
• Is your loft suitable to be converted?
• Your proposed use of the converted loft will determine the design
• Will it be a ‘Room in Roof’, a ‘Dormer Loft Extension’ or a will it require changing the roof structure?
• How will you access the loft?
• Where will the stairs go? and how will that affect your ceiling joists?
• Lighting and heating your new loft conversion
• Insulating and ventilating your loft conversion.
• Do you need plumbing for a bathroom or en-suite?
• And finally, you must consider the fire risks and an escape route.

The cost of converting a loft depends on a number of factors including:

• Size and structure of the conversion
• Whether your roof needs to be strengthened
• Whether you want dormer windows or there are other structural alterations to your roof
• Whether you want a bathroom or en-suite in the loft

‘Room in Roof’ loft conversions are the least expensive at around £13,000 to £15,000. They will involve reinforcing the floor, installing roof vents such as Velux™ windows, improving insulation, a staircase, lighting & heating and complying with fire safety regulations.

‘Dormer Loft Extensions‘ are next in line at £20,000 plus and include everything that a room in roof conversion requires except building dormer windows instead of skylights.

Changing the Roof Structure or ‘Raising the Roof’ are the most expensive type of loft conversion. They will certainly require planning permission and involve removing and rebuilding your existing roof.

A loft conversion on a bungalow can be up to 20% cheaper than one on a two storey house.

Planning Permission

Many designs of loft conversion do not need planning permission as long as you satisfy the conditions of Permitted Development. In simple terms this means not altering the shape or size of your existing roof.

Skylights can be fitted and so can dormers providing they are no higher than any part of the existing roof.and don’t project forward of it at the front.

Any alterations to your existing roof which are outside of the Permitted Development conditions means that your loft conversion will require planning permission.

Building Regulations

All loft conversion require Building Regulations approval. A building control surveyor will inspect the work at various stages and issue a completion certificate.

The main areas covered by Building Regulations are effective insulation and ventilation, maintaining a headroom of at least 2 metres in the stairway and satisfying electrical and fire safety regulations.

Finally, if your home is attached to another property, you will need to notify your neighbours and meet the requirements of the Party Wall Act.

It is important that before starting work on your loft conversion you contact your local Planning Office and Building Control Department to check that your proposals are withing current regulations.

The main factors involved in assessing whether your existing loft can be converted in useful living space include:

Available Head Height – There must be at least 2.2 metres between the top of the ceiling joist (which will form the loft’s floor) and the bottom of the ridge. It is also important to consider how much of the new living space will provide usable head room. You don’t want to disappointed by having standing room only in the centre of the loft conversion.

Roof Structure – On a house with a traditional roof rather than roof trusses, converting a loft will be easier and cheaper. This is because the traditional roof structure allows the space to be opened up with less structural work required. Trussed roofs normally require steel beams between load bearing walls and at the ridge.

Any Obstacles such a Water Tanks – Removing a water tank from your loft will require changing your central heating system to a sealed system or installing a combi boiler. And whilst both options involve additional cost, use of your loft conversion can be seriously compromised without doing this.

The best position for stairs up to a loft conversion is in line with the roof ridge as this will provide the head height required.

If there is room, it is always better if the new staircase starts on the existing landing, otherwise it could mean taking space from one of the first floor bedrooms.  Alternatively, space for the stairs can be created by building a dormer or converting a hipped roof to a gable.

Once the position of the stairs is decided, regulations apply to the number of steps in a straight line, the pitch of the stairs, size of the steps and the requirement for ballustrading.

Ceiling Joists – For most loft conversions new ceiling joists will be required to take the weight of the loft floor. A structural engineer will be able to specify the size and position of the new joists.

Fire safety in a loft conversion is one of the main aspects covered by Building Regulations and your Building Control Surveyor will pay particular attention to how this is achieved.

The main points to consider are:

• In a bungalow loft conversion, egress windows with minimum openings of 450 mm x 450 mm (and at least 0.33m² in area) are required in all first floor habitable rooms except bathrooms. The bottom of any skylight opening must be between 800 mm and 1,100 mm from finished floor level.
• In houses, escape windows are not an option so a fire escape stairway must be installed.
• A fire door must be fitted at either top or bottom of the new stairway.
• Floor joists must provide 30 minutes of fire protection and this often means double plaster boarding the ceiling of the rooms below.
• Inter-connected smoke alarms must be fitted so that if one is activated, alarms on all of them sound.

Lighting – Adding Natural Light to a Loft Conversion

Natural light can be brought into a loft conversion using either skylights such as Velux™ windows or by building a dormer.

Skylights are the least expensive option as they follow the pitch of the roof and are fitted between the roof timbers. Tiles and battens are removed to make room and flashing is added to make them watertight.

Dormer windows are more expensive because of the additional work involved in building them but they do add space as well as light to the loft conversion.

Skylights and dormer windows will also provide ventilation but you should consider other form of ventilation such as airbricks, trickle vents and extractor fans in wet rooms.

Artificial Lighting

As with any other room in your home, electric lighting will be required and there is a wide range of options available. Because you have a ‘blank canvass’ with this room you can add a combination of different types of light fittings to suit the use you intend to make of the new space.

Heating a Loft Conversion

If you intend to extend your central heating system into the loft you may need a larger capacity boiler and / or another pump. Alternatively, independent heat sources are available such as electric storage heaters (you should contact your energy supplier about Economy 7 if you choose to install these).

Underfloor heating is also an option, especially if you are intending to have a bathroom or en-suite with a tiled floor.

Insulation is required in  your loft conversion just as it is in any other external room in your home.

Your loft conversion will require insulation of one type or another in all surfaces. This will include external walls, any internal stud walls, the roof (including dormers), the floor and also any party walls.

Insulation will not only keep your loft conversion warmer, it will reduce noise between the various rooms of your home and your neighbour’s home.

If the main purpose of your loft conversion is to provide an extra bedroom, it makes sense to fit a bathroom or en-suite in there, space permitting.

You should consider the following points:

• A shower will require full headroom but a bath can be installed under the eaves.
• Also, a toilet and a washbasin will need full headroom.
• Voids in stud walls can be used to conceal cisterns, shower mixers and pipework.
• Installing wall-mounted sanitary ware will provide more space in a small bathroom.
• Large mirrors and strong lighting will create an illusion of a larger room.