Loft Conversion Guide in the UK

Loft Conversion Guide in the UK

Loft Conversion in the UK: How to start? More and more UK homeowners are converting a loft or attic into a living space. This is a popular home addition as it adds up to 20% to the value of the property. But before you begin, find out what are involved and how will you start in this Loft Conversion Guide.

These are the 5 things you need to consider before you convert a loft:

Planning Permission

Planning permission for loft conversion in UK is not normally required as it falls under Permitted development rights. However, you should follow the following guidelines:

Volume (All previous roof space additions are included):

  • Volume of 40 cubic metres additional roof space for terraced houses
  • Should no exceed Volume of 50 cubic metres additional roof space for detached and semi-detached houses


  • No extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway
  • No extension to be higher than the highest part of the roof
  • Roof extensions, apart from hip to gable ones, to be set back, as far as practicable, at least 20cm from the original eaves


  • Materials to be similar in appearance to the existing house


  • No verandas, balconies or raised platforms
  • Side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor
  • The roof enlargement cannot overhang the outer face of the wall of the original house.

If you own a flat or maisonette, please know that there is a separate regulation for this housing type.

If you are living in a restricted zone and other designated areas such as national parks or heritage site, roof extensions are not allowed.

To know more about Permitted Development Rights for Loft conversion in the UK, check our previous post here.

Loft Weight

An important thing to know beforehand is to check whether your home can hold the weight of a new living space. Your loft will add extra weight to your house and even if it’s just a slight increase, it is best to be safe. To do this, start locating the structural elements of your house: Columns, Beams and Walls. For example, if you are adding new floors, joist must be attached to the beams or a column that is continuous to the foundation of the house. Do not attach joists to small partitions and non load bearing walls.

If you are still in doubt if your house can carry a new loft, consult a professional or building control officer to check these elements.

Loft Height

Building regulation requires at least 1.80 meters head height (measured from the center to the highest pitch or apex of the roof) is the standard for lofts. However, it is advisable to have at least 2.30-2.50 meters headroom (From Floor to roof). It will give you more comfort in the space.

Natural Light

Loft Conversion Guide - Dormer Windows and Skylight example
Dormer Windows and Skylight Installed in the Roof

It is ideal to add windows as source of natural light and ventilation. Skylight is the best option to add natural light and cut cost on your electricity bill. You can either install a operable skylight or a fixed skylight. Additionally, you can add dormer windows to your roof. Please note that if you are planning to have dormer windows at the front or facing the road, you will need planning permission.

For safety, make your operable skylight or windows large enough to serve as emergency exit in case of occurrence of fire and other emergencies.

Loft Insulation and Other Considerations

Loft Conversion Guide - Batt insulation or Blanket Insulation
Most common insulation is the Batt/Blanket Insulation

You have different options for loft insulation:

  • Batt or blanket – most common type, you can DIY this insulation. Available in rolls while Some materials of this type can cause allergy, better check the material first.
  • Loose Fill – made of granules or lightweight materials. You will need a contractor for this.
  • Sheet – You can use this insulation for roof slopes

It is best to install insulation for your comfort and protection from the weather. It is an important addition especially if you are converting an attic to a living space.

Other utilities to check:

  • Check electrical and plumbing lines. You can ask your loft builder or utility person to check if you can extend the lines if you are planning to add new bathroom or new outlets in your loft.

It is always possible to DIY your loft conversion, however, there are certain aspects of the loft conversion that needs professional advice.

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