Loft Conversions in Preston, Lancashire and the North West

What types of loft conversion are there?

There are five main types. Which one suits your house depends on the roof shape, the pitch, the head height and the planning rules for your property.

• Velux or rooflight conversion. Windows are fitted into the existing roof slope and the roof shape does not change. It involves the least structural work, but it only works where there is already enough head height.
• Dormer conversion. A box shaped extension is built out from the rear roof slope, with a flat roof and vertical walls. It adds head height and usable floor area, and it is the most common choice on terraced and semi detached houses.
• L shaped dormer. Two dormers meet at a corner, one on the main roof and one on the roof of a rear outrigger. It suits many older terraced houses and creates enough room for a bedroom and a bathroom.
• Hip to gable conversion. On a hipped roof, the sloping side is rebuilt as an upright gable wall, which makes the loft much bigger. It is often combined with a rear dormer on semi detached and detached houses.
• Mansard conversion. The rear slope is rebuilt almost vertically with a flat roof on top. It gives the most space, but it changes the look of the house more than the other types, so it usually needs planning permission.

Is my loft suitable for conversion?

Most lofts can be converted, but three things decide how easy it is.

• Head height. As a rough guide you need about 2.2 metres from the top of the ceiling joists to the underside of the ridge. Less than that can sometimes be solved with a dormer or by lowering the ceiling below, but it adds work.
• Roof structure. Older houses usually have a traditional cut roof with rafters and purlins, which is simpler to open up. Many newer houses have trussed rafters with diagonal braces across the loft. These can still be converted, but the structure has to be redesigned with steels, which a structural engineer specifies.
• Room for the stairs. The new staircase usually goes above the existing stairs. Building regulations set minimum headroom over the stairs, with some allowance under a sloping roof, so the stair position is one of the first things we check.

Water tanks, chimney stacks and a shared party wall all affect the design too. We look at all of this at the survey before giving you a quote.

Do I need planning permission for a loft conversion?

Often not. In England, many loft conversions on houses are allowed under permitted development rights, as long as they stay within set limits. The main ones are:

• no more than 40 cubic metres of extra roof space on a terraced house, or 50 cubic metres on a detached or semi detached house, counting any earlier roof extensions
• no part of the work higher than the highest part of the existing roof
• no extension beyond the roof slope at the front of the house that faces the road
• materials similar in appearance to the existing house
• side facing windows obscure glazed, and fixed shut unless the opening part is more than 1.7 metres above the floor
• no verandas, balconies or raised platforms

Permitted development does not apply to flats and maisonettes, and roof extensions are not allowed under it in conservation areas. Some houses, especially on newer estates, have had these rights removed by a planning condition. Mansard conversions and most front dormers need a full planning application.

Even when planning permission is not needed, a lawful development certificate from the council gives written confirmation that the work is lawful, which is useful when you sell. We confirm the planning position for your house before any work starts.

What building regulations apply to a loft conversion?

Every loft conversion needs building regulations approval, whatever the planning position. The main areas are:

• Structure. New floor joists to carry the room, steels where the roof structure changes, and calculations from a structural engineer.
• Fire safety. Turning a two storey house into three storeys changes the escape route. This usually means fire doors onto the stairs on every floor, so the stairs form a protected route out of the house, and mains powered, interlinked smoke alarms.
• Stairs. A proper fixed staircase with enough headroom and safe handrails. A loft ladder is not enough for a habitable room.
• Insulation and ventilation. The roof, dormer walls and floor are insulated to current standards, with ventilation to prevent condensation.
• Sound. Sound insulation in the new floor between the loft room and the rooms below.

Building control inspect the work at key stages and issue a completion certificate at the end. Keep it with your house deeds, because a buyer's solicitor will ask for it.

Do I need a party wall agreement?

If your house is terraced or semi detached, usually yes. Steel beams are often set into the shared wall, and that work is covered by the Party Wall etc. Act 1996. You serve notice on the neighbour before work starts. If they agree in writing, no surveyor is needed. If they do not respond or they dissent, a party wall surveyor prepares an award. We explain what applies to your house at the survey.

What affects the cost of a loft conversion?

• The type of conversion, such as Velux, dormer, hip to gable or mansard
• The size of the loft and the head height
• How much steel and new floor structure is needed
• The staircase and where it goes
• Windows, and whether you add a bathroom
• The finish and fittings you choose

For a guide price, use the free loft conversion cost calculator. It works out an estimate from the type of conversion and the size of your loft. Your survey and written, fixed price quote then confirm the price.

How does a loft conversion project run?

1. Survey and written quote

   We look at the head height, the roof structure, where the new stairs can go and access, then give you a written, fixed price quote.

2. Design and approvals

   Drawings, the structural engineer's calculations and building regulations approval, plus planning permission or a lawful development certificate where needed, and party wall notices if you share a wall.

3. Structure and roof

   Scaffolding goes up, steels and new floor joists go in, then the dormer or roof alterations, windows and insulation. The new staircase is connected to the floor below near the end.

4. Finish and sign off

   Electrics, plastering, doors and decoration, then building control inspect the work and issue a completion certificate.

Timescales depend on the size and type of project and are confirmed in your written quote.

Why choose Introspec Construction for a loft conversion?

Introspec Construction is a builder based in Preston, Lancashire. The team has more than 100 years of combined experience and has completed hundreds of loft conversions. We are fully insured, and every job is priced with a fixed price quote, so you know the cost before work starts.