​Loft conversion information

​This page aims to answer frequently asked loft conversion questions

Question: What is planning and building control?

Answer: Planning permission and building regulations are often befuddled, when planning a property conversion, it is crucial to understand the difference, and when each should be required. You may only require building regulation approval, or both!

Generally, planning permission determines if a building can be constructed or extended, while building regulations manage how such building works are undertaken. Both are managed by your local authority. Building control approval can also be granted by a registered independent inspector

Question: What permission do I need for my loft conversion?

Answer: you will need Building Regulations and we recommend gaining a certificate of lawfulness, this will be granted by your planning department.

Certificate of lawfulness

From 1 October 2008 a loft conversion for your home will be considered to be permitted development, and will only require plans and application for a certificate of lawfulness subject to the limits and conditions set out below:

    1. A volume allowance of 40 cubic metres for terraced houses

    2. A volume allowance of 50 cubic metres for detached and semi-detached houses.

    3. No extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway.

    4. No extension to be higher than the highest part of the roof.

    5. Materials to be similar in appearance to the existing house.

    6. No verandas, balconies or raised platforms.

    7. Side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.

    8. Roof extensions not to be permitted development in designated areas*.

    9. Roof extensions, apart from hip to gable ones, to be set back, as far as practicable, at least 20cm from the eaves.

Loft Building Regulations

The Building Regulations ensure that developments are built within a set of pre-defined standards to ensure safe building practices and good workmanship. The standards cover such things as the structure, fire safety, drainage, energy conservation and disabled access within buildings

Full plans (allows your plans to be approved prior to construction)

​Building notice (allows you to start work on site within 48 hours of plans and application submission)