JM Construction Blog

Dormer Conversion: Adding Space and Value to Your Home

Written by James Murdoch | Jun 4, 2024 9:54:00 AM

A dormer conversion can be a great way to add square footage to your home and increase the value of your property. By converting unused attic space into a functional room, such as a bedroom, home office or entertainment area, you can maximise your living space without expanding your property’s footprint. This can be especially beneficial in urban areas where outdoor space for extensions is limited.

So, what do you need to know about dormer conversions before you start planning? Do you need planning permission? And would your home be suitable?

Read on to find answers to these questions and more!

 

What Is a Dormer Conversion?

A dormer conversion is a type of loft conversion that creates more usable space and headroom in your loft by adding a box-shaped structure with vertical walls and a flat or pitched roof (a dormer) to your existing roof. This gives you extra floor space and more headroom in your loft, making it suitable for conversion into a bedroom, bathroom, home office or another living area. Plus, with a dormer conversion, you have the vertical space to install full-sized windows, bringing in natural light and ventilation to your new space. As a result, this type of conversion is particularly popular among homeowners who wish to maximise their living area without encroaching on garden space or undergoing the costly process of moving to a larger home. They can be built on various types of houses, including terraced, semi-detached and detached homes.

 

 

Types of Dormer Conversions

OK, next question: are there different types of dormer conversions? If so, how do they differ?

Put simply, yes! There are three main types of dormer conversion that you can choose from. Each type has its advantages and the right choice for you will depend on the existing structure of your home and your specific needs for space, light and design.

Here’s an overview of the three most common types of dormer conversions:

  • Flat roof dormer: This is the most popular type as it offers substantial additional headroom and floor space with a simple and cost-effective design. This design allows for large windows, enhancing natural light and ventilation in the newly created space.
  • Gable fronted and hipped roof dormer: This type of dormer adds aesthetic appeal with more traditional looks that complement existing architectural styles. They are often chosen for their ability to blend with the rest of the house, enhancing the roofline and increasing the property’s curb appeal.
  • Shed dormer: This has a sloped roof that is less steep than the main roof, which provides a simple yet effective space solution. It is particularly suited for adding functional living space under the existing roof, and is often used for bedrooms or bathrooms with ample headroom.

Is My Home Suitable?

Unfortunately, dormer conversions are not suitable for all types of properties. Whether you can add one to your home will depend on several structural and architectural considerations. You will also need to find out if the structure will fall under permitted development rights or if you will need to apply for planning permission

Here are a few factors that can impact whether a dormer conversion is suitable for your home:

  • Roof structure. Homes with certain types of roof structures, like truss roofs, may require more extensive and costly modifications to support a dormer. The existing roof must also have enough space and the right configuration to accommodate the dormer conversion. Homes with traditional cut and pitched roof structures are typically more suitable for this type of loft conversion.
  • Available head height: There should be adequate head height in the existing loft space. A minimum of 2.2 meters is usually recommended.
  • Architectural style: The architectural style of the home should be considered to ensure that the dormer complements the overall look of the house. In some historic districts or neighbourhoods with strict community guidelines, modifications that alter the external appearance might not be allowed.
  • Structural integrity: The existing structure of the home must be capable of supporting the additional weight and alterations involved in adding a dormer conversion. A structural engineer might need to assess the house to determine what reinforcements are required.
  • Planning permissions and building regulations: Some areas, especially those in conservation areas or designated as Areas of Outstanding Natural Beauty, may have stricter controls on modifications that affect the roofline. Additionally, all dormer conversions must comply with building regulations to ensure that the construction is safe, structurally sound, and energy efficient. You will need to secure approval from your local authority before commencing work on a dormer conversion (more on this in the final 2 sections).

 

Do I Need Planning Permission for a Dormer Conversion?

In the UK, many dormer conversion projects can be undertaken under permitted development rights, which means they do not require planning permission. However, they must adhere to certain conditions and limits in order to qualify for these rights. 

Namely, the dormer conversion must:

  • Not exceed the highest part of the existing roof. The dormer must sit below the existing roof peak.
  • Be set back at least 20 centimetres from the original eaves. This helps integrate the dormer into the roof's design without it appearing overly dominant.
  • Use materials similar in appearance to the existing house. This requirement ensures that the conversion is in keeping with the external character of the property and its surroundings.
  • Not include any balconies, verandas or raised platforms. These features are not covered under permitted development rights and would require a separate planning application.
  • Not face onto a highway: The dormer should not face directly onto or be visible from a highway.
  • Adhere to volume limits: For terraced houses, the volume addition must not exceed 40 cubic meters, and for detached and semi-detached houses, it should not exceed 50 cubic meters.

It is important to note that the specifics can vary depending on local council guidelines, and homeowners should consult their local planning authority to confirm whether their project qualifies as a permitted development or if they need to apply for planning permission.

What About Building Regulations?

Finally, whatever type of dormer you opt for, and regardless of whether or not the conversion falls under permitted development rights, you will need to ensure that the construction complies with UK building regulations. These regulations ensure that the conversion is structurally sound, safe, energy-efficient and accessible

Key aspects of these regulations include:

  • Structural integrity: The conversion must be structurally sound, supporting the weight of the new construction without compromising the existing building's stability.
  • Fire safety: Adequate fire safety measures must be in place, including fire-resistant materials and proper escape routes.
  • Insulation and energy efficiency: The dormer must be properly insulated to meet energy efficiency requirements, helping to reduce heat loss and ensuring the space is comfortable.
  • Ventilation: Proper ventilation must be installed to prevent condensation and ensure a healthy living environment.
  • Sound insulation: Especially important in semi-detached or terraced homes, soundproofing measures may be required to minimise noise transfer.
  • Accessibility: If the dormer conversion includes facilities like a bathroom, it should be accessible, where feasible, to meet the needs of all potential users.

Compliance with these regulations not only ensures safety and comfort but also enhances the overall value and usability of the dormer conversion. It’s always a good idea to work with professionals like JM Construction who can provide guidance and make sure that your property’s new addition meets all legal standards. 

Ultimately, with the right planning and professional guidance, a dormer conversion can transform your home into a more spacious, functional and attractive space for you and your family to enjoy for years to come!