Loft conversion3 min read

Loft conversions, everything you need to know

A brick house with a zinc rear dormer and a rooflit rear extension.
A brick house with a zinc rear dormer and a rooflit rear extension.Completed work, photograph

Loft conversion company in London. Dormers and mansards, designed, priced and built by one team.

Dormer loft conversions are the most common kind in London. You will have seen them in every neighbourhood. This is mainly because they are versatile. They can be installed on most types of properties (subject to planning approval). That runs from detached houses to top floor maisonettes. In terms of the process, this is how a loft conversion works. A rectangular box shaped structure is built up in place of the pitched roof.

What is a dormer loft conversion? A new structure is built on the roof. It has a flat roof and walls set at ninety degrees to the floor. This gives much more usable space in the loft and a comfortable ceiling height. Typically dormers are located at the rear of the property. Generally the new structure must fit in line with the current ridge height. The ridge may be too low to achieve adequate head height. If so, permission can be sought from the local planning department.

What are the different types of dormer loft conversion? There are quite a few, and which one suits depends on the house:

  • Flat roof: built at the rear of a terraced house. The gable or boundary walls are already there. These add the most loft space for the money, and are the most common.
  • Side: the dormer box is built into the side of the sloped roof.
  • Front pitched: also called a gable dormer. It is a small dormer topped with its own small gable roof.
  • L shaped: one of the larger options, built on properties with an outrigger. Two parts form an L and add a great deal of space.

Will I need planning permission for my loft conversion?

Here is one of the great advantages of dormer loft conversions. They are included in the homeowners permitted development rights. These rights allow homeowners to add liveable space and extend their homes. They do not need to go through the full planning application process. That holds as long as specific criteria are met and guidelines are followed. Some examples include:

Your current home:

  • Is not a building containing one or more flats.
  • Has not already had additional storeys added to it under permitted development rights
  • Was not changed from non-residential to a house under permitted development rights.
  • Was not built under permitted development rights.
  • Is not in a conservation area.

Limitations on the proposed development:

  • Materials must be similar in appearance to the existing house
  • The enlargement is measured against the original roof space. A terraced house may add no more than 40 cubic metres of volume. Other houses may add up to 50 cubic metres.
  • Must not exceed the height of the existing roof.
  • The front roof must not exceed the existing roof slope.
  • Must not include verandas, balconies or raised platforms. Juliet balconies are permitted.
  • Side-facing windows must be obscure-glazed.

Further details can be found here:

the GOV.UK householder permitted development guidance

Is my home suitable for a loft conversion? Almost any house with a pitched roof can take a dormer. It needs enough head height. The usual candidates are London terraces, end of terrace, semi detached and detached houses. Edwardian, Victorian, 1920s and 1930s houses, new builds and bungalows all convert well. Conservation areas, flats and maisonettes need more care and often a planning application.

What are the benefits of the loft conversion? One of the main benefits of loft conversions is added property value. It comes from adding an extra bedroom and en-suite. However, not all properties would be able to achieve this. It is dependent on location, circumstances or existing property condition. Unlike a velux loft conversion, the dormer will allow vertical walls and normal stairs. Skylights allow light onto first floor dark areas. You would also benefit from additional storage and en-suite. Most dormer loft conversions will add a good size bedroom space. A lot of options can be added. They range from Juliet balconies to flat roof skylights and built in wardrobes. A dormer is usually the cheapest of the loft conversions.

To talk to the team, send two lines through the contact form. You can also call 020 7731 6841. We usually reply within a few hours, weekends included.

Where NU Projects builds lofts

We build loft conversions across West and North London. That includes St John’s Wood, Highgate, Barnes, Battersea and Chelsea. The scope is set out under extensions and lofts.

This is the work we do. Loft conversion company in London, or ask for a cost estimate.

Published 29 August 2022. Written by the NU Projects studio, edited since for house style and accuracy.

Filed underLoft conversion

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