Planning Permission For
loft Conversions

In most cases, loft conversions in North London, Essex, and Hertfordshire do not require planning permission. However, if the roof space is extended or altered beyond certain limits and conditions, permission will be necessary.

Under regulations introduced on 1 October 2008, loft conversions are classified as permitted development, meaning they do not require a planning application, provided they meet the following criteria:

  • A maximum additional roof space of 40 cubic metres for terraced houses.
  • A maximum additional roof space of 50 cubic metres for detached and semi-detached houses.
  • No extension beyond the plane of the existing roof slope on the principal elevation facing the highway.
  • The extension must not exceed the highest point of the existing roof.
  • Materials used must match the appearance of the existing house.
  • No verandas, balconies, or raised platforms.
  • Side-facing windows must be obscure-glazed, with any openings positioned at least 1.7m above floor level.
  • Roof extensions are not considered permitted development in designated areas.
  • Except for hip-to-gable extensions, roof extensions must be set back at least 20cm from the eaves where feasible.

For architectural drawing services, we recommend ELC Planning and Design, a division of The ELC Group.

ELC Planning and Design specializes in providing services for residential and commercial clients across North London, Essex, Hertfordshire, and surrounding areas. Their expertise includes planning and design for home renovations, extensions, garage conversions, loft conversions, and new builds.

For expert guidance on building planning and design, visit the ELC Planning and Design website.

Velux

Velux and rooflight are the same conversions. This type of loft conversion is generally very cost effective and does not need planning permission.

Hip to Gable

A hip to gable loft conversion requires major changes to the roof. A gable wall is built up to the ridge point and a new section of the roof is built to fill in the gap.

Dormer

A Dormer loft conversion extends the roof, adding space and headroom with a horizontal ceiling and vertical walls, making it ideal for attics with limited height.

Mansard

A mansard roof has two slopes: a steep 72-degree lower slope and a nearly horizontal top, maximizing loft space.

Frequently Asked Questions FAQs

In general, planning permission is required for any additions or extensions that alter the external appearance of a property. Flats and maisonettes are subject to stricter regulations than houses. Internal modifications typically do not need permission, but converting a property into separate dwellings, such as flats or bed-sits, does require approval.

Not all loft conversions need planning permission. However, if your property is in a conservation area or is a listed building, permission may be necessary for work that would otherwise not require it. It is always advisable to check with your local authority. If you are unsure whether your project falls within these guidelines, consulting your local authority for guidance is the best approach. Planning issues can be complex, and proceeding without the necessary approvals could result in enforcement action, requiring costly demolition or modifications.

Certain alterations to a house, rather than a flat or maisonette, may be made without planning permission under “permitted development” rights. These rights apply to an “original house,” meaning the property as it was first built or as it stood on 1st July 1948 if built before that date. If the original house has not been extended, including loft conversions, you may be able to develop your property under these rights.

However, permitted development is subject to restrictions on height and volume, with various conditions to consider. It is advisable to consult your local authority or an architect for guidance. Additionally, if your home is in a conservation area, your local authority may have withdrawn permitted development rights.

This process involves many variables, so your first step should be consulting your local authority and an architect. To get a general idea of what may be approved, you can also review similar developments in your neighborhood that have already received permission.

Contact your local authority for the necessary forms and guidance, or let us handle the entire process for you.

The local authority typically provides a decision within eight weeks.

The local authority will inform your neighbors and other interested parties for their input. Your application will be available for public inspection at the local authority offices and will be assessed based on planning considerations. Objections alone cannot justify rejection; the council must provide valid planning reasons if they refuse your application or impose conditions.

A party wall is a shared structure between adjoining properties, such as the common wall between terraced houses. It also includes separating floors between flats (a “party structure”) and garden walls (a “party fence wall,” excluding wooden fences).

Since most loft conversions may impact a party wall, you must notify all adjoining property owners. Typical work requiring notification includes:

  • Cutting into a wall to insert a beam for a loft conversion.
  • Altering the height of a party wall.
  • Demolishing and rebuilding a party wall, often for an extension.
  • Underpinning a party wall.

Minor works, such as installing shelves or drilling for plugs and screws, do not require a party wall agreement.

It is always advisable to consult your neighbors before undertaking major work on your property. Keeping them informed before they receive official notifications from planners can help prevent disputes.

The next step is to provide written notice to all affected owners, detailing what work you plan to do, when it will take place, and how it may impact them. You should serve this notice at least two months before work on the party wall begins, though an adjoining owner may agree to an earlier start. Their agreement must be given in writing.

If no agreement is reached, an “agreed surveyor” can be appointed to draft an “award.” This document outlines the work, the method and timeline for completion, and includes a report on the current condition of the adjoining property to resolve any potential disputes over damage. Alternatively, each party can appoint their own surveyor, though the cost is usually borne by the person carrying out the work, making a single agreed surveyor a more cost-effective option.

For more details, visit the relevant government planning and building regulations website.

Each local authority has a building control office responsible for ensuring that all construction work complies with building regulations, including approved materials, design, and construction methods. Legally, building work is defined as:

  • The erection or extension of a building.
  • Alterations to an existing building.
  • A material change in the use of a building.
  • The provision, extension, or alteration of controlled services or fittings, such as drainage, boilers, unvented hot water systems, mechanical ventilation, or replacement windows.

Even internal layout changes, including non-structural ones, can impact fire safety. It is advisable to consult the local authority building control office before proceeding to avoid unexpected requirements, such as additional fire doors, which could make your project impractical or costly.

General minor repairs that involve replacing like-for-like materials typically do not require approval. If unsure, contact your local building control office for guidance.

This information is for general reference only. The Loft Converter disclaims any responsibility or liability (including for negligence) regarding the use of this content.