Planning Permissions and Regulations for Building Double-Storey Extensions

double story regulation in uk

Maximise the potential of a property by adding a double-storey extension. The main idea for a great two-storey extension is to add new rooms both upstairs and downstairs that fit well with your existing home. Ideal for compact homes and expanding families, it provides the most straightforward solution for expanding living space and incorporating an additional bedroom.

Benefits of double-storey extension:

  • More space
  • Privacy and noise reduction
  • Add value to your home
  • Better views

The two-storey extension is a trendy option due to its adaptability and the range of ways it can expand and enhance your house. There are some regulations while building a two-storey extension that need to be in consideration.

How to Plan Double-Storey Extension?

Planning a double-storey extension consists of the following steps:

  • Start with project planning and design, which includes your requirements and goals. Book an appointment with the architect and discuss the structure and design concept.
  • When discussing structure, mention the roof type, doors, windows and how rooms should be utilised.
  • Get all the necessary permissions for the construction and make sure to follow all the safety aspects.
  • It is a very important part of setting your budget; keep in mind all the expenses like architecture fees, design, construction and any other expenses that come to your mind.
  • After discussing your budget, then move towards the design and interior. It will help you to narrow down your options.
  • Select the material, shades and finishes that you want to implement in your newly built extension.
  • Then, start the construction process and wait for completion.

What are the Two-Storey Extension Regulations?

  • A double-storey extension is limited to a maximum depth of 3m on both floors. If your extension exceeds this depth, you will need planning permission.
  • The eaves height of the double-storey extension must not surpass the existing height, and the extension’s roof should not be taller than the original house roof.
  • If the double-storey extension is within two meters from your property boundary, the eaves should not exceed a height of three meters.
  • The two-storey extension must avoid adding balconies, raised platforms, microwave antennas, and chimneys or making any changes to the roof of the original house.
  • External materials used for the double-storey must harmonise with those of the existing house.
  • The roof slope of the two-storey extension must closely resemble the existing home’s roof.
  • The new two-storey extension should not come closer than seven meters to any property’s edge or go past the back wall of the existing building by more than three meters.
  • If you want a window on the side of the first floor, it should be hard to see through and should not open unless the part that opens is placed higher than 1.7 meters from the floor inside the room.
double story regulations
double story regulation uk

Types of Double-Storey Extension

Wrap Around: It involves merging both side and rear extensions of the house and encircling the existing house, which is why it is called wrap around.

Side Returns: It uses the most minor possible place. You can use a small area on each side of your house without disturbing the beautiful garden.

Rear Extension: The rear wall extension is located at the back of your existing structure. This kind of extension works well for both houses that are detached and for those who share a common wall with one another.

Front 2-Storey Extensions: this extension is within an already built structure and is the least usual type because it can completely modify the look of the building.

Permission is not always required to build a double-storey extension, but if we live in an area where permission is required to do any construction, we must get planning permission and follow the building regulations.

What is Planning Permission?

This encompasses the utilisation of the land and structures, the visual aspects of buildings, landscaping assessment, access to roadways and the influence the development will exert on the overall environment.

How to Prepare a Planning Permission Application?

When submitting a planning application, providing a comprehensive set of fully filled-out forms is crucial. Accurate scale drawings should accompany every application. In addition to detailed planning drawings and the completed application form, a design and access statement are often required. Even when not mandatory, including one is advisable.

The drawings should clearly depict all architectural elements, encompassing walls, windows, doors, room materials, and building and ceiling height.

Moreover, a design and access statement should involve different kinds of new developments or changes in how a property is used. This statement explains how design standards and planning policies match the plan for the project.

What is Building Regulations Approval (Building Control Approval)?

Building regulations approval sets forth universal standards that must be adhered to in all buildings to ensure the safety of individuals within or around them. These regulations comprise a collection of approved documents that address the technical aspects of construction projects.

For a seamless construction process, obtaining planning permission and building regulations approval is required. It is highly recommended that you engage in discussions with residential architects before initiating any application submissions.

Cost of Double-Storey Extension

The cost of a double-storey can depend on factors like

  • Location
  • Site Access
  • Soil composition
  • Size in square meters
  • Type and shape of the roof
  • Finishes like windows, roof-lights, underfloor heating, floor etc.

The average cost of a double-storey extension in the UK varies from around £2000 to £2,500 per sqm, excluding finishes.

In London, the average cost is around £3000 to £3500 per square meter, excluding finishes.

If you want to extend your house space, get in touch with experts at Construct and Furnish London, or visit our website for more information. We will provide you with suitable suggestions according to your property. Simply contact us and book an appointment today!

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