London Loft Conversion Cost

How Much Will my Loft Conversion Cost?

The cost of your loft conversion will depend on your roof structure, the existing available space and whether any alterations need to be made to the floor below to accommodate the staircase.

Room in Roof Loft Conversion

A basic ‘room in roof’ loft conversion is the cheapest and could start at around £15,000. This will usually involve:

  • the reinforcement of the floor
  • a couple of skylights
  • added insulation
  • a staircase to the loft
  • electrics, lighting and heating
  • fire safety measures to comply with Building Regulations such as fire doors and smoke alarms.

Dormer Loft Extension

The second option which does not require dramatic changes to the roof is to do the above and add dormer windows. This will increase the useable floorspace and can be used to add head height which gives you more options when it comes to placement of the stairs. This will cost upwards of £20,000. However the average dormer loft conversion with a double bedroom and en suite costs about £35,000–£45,000.

 

loft dormer
loft dormer

How Much Will my Loft Conversion Cost?

 

Loft Conversions Which Involve ‘Raising the Roof’ or Changing the Roof Structure

This option is the most expensive as it require the removal and rebuild of the existing roof. It also requires planning permission approval so you local planning permission application cost must be added on.

Another added expense will be the additional design work that may be needed as it is more complicated that a room in roof, or dormer loft conversion. This type of work is likely to cost upwards of £40,000.