Types of Loft Conversion: Your Complete Guide

Opting for a loft conversion is a popular choice among UK homeowners who are looking to expand both the size and value of their properties.

Although the concept of loft conversion may seem straightforward, choosing the right type of attic conversion for your unique property type and needs can be challenging. The choice can be overwhelming, with various types available, each with unique specifications and requirements.

This page will dive deep into the specifics of each loft conversion type, outlining their key features, the regulatory and permission requirements they entail, and the cost implications involved. Keep reading to find out which type is suitable for your loft!

The types of loft conversion are Velux (or roof light), dormer, hip to gable, mansard, modular, and bungalow loft conversion, each offering different benefits and suited to varying property types and needs.

The price per square metre for different types of loft conversions in the UK can vary significantly based on specifications and geographic location. On average, you might expect to pay between £1,200 and £2,500 per square metre.

However, more complex conversions such as mansard or modular types might see costs at the higher end of this range or even above, especially in areas like London, where prices tend to be higher.

The duration of loft conversion projects in the UK typically ranges from 4 weeks for simpler Velux conversions up to 12 weeks for more complex mansard or modular conversions. The exact timeline can vary based on project complexity, size, and any unforeseen challenges that arise during construction.

Below we share a detailed overview of loft conversion types and visual representations for each category, alongside an explanation of the applicable building regulations.

Velux conversions involve installing windows into the roof's slope, making it a straightforward and cost-efficient way to expand your loft. It's ideal for adding light and ventilation without altering the roof's structure.

Velux conversions are ideal for homes with ample attic space that require minimal alteration to be functional. They're particularly suited to properties where maintaining the external appearance of the building is crucial, as the conversion does not impact the roof's external shape.

The cost of a Velux loft conversion varies, but it is generally the cheapest loft conversion, with prices starting from around £15,000 to £20,000. The price per square metre typically ranges from approximately £1,200 to £1,800 This estimate includes the cost of the windows themselves, installation labour, and basic interior finishing.

The duration for completion can be as little as 4-6 weeks, making it a quick and efficient option for many homeowners.

Building regulations are required for a Velux loft conversion to ensure the conversion is safe and meets current standards for insulation, fire safety, and structural integrity. However, planning permission is often not needed unless the property is listed or located in a conservation area.

A dormer conversion involves extending the existing roof vertically to create box-shape protrusion. This type of conversion is more complex and expensive than a Velux conversion but provides significantly more usable space.

Dormer conversions are suitable for almost any property with a sloping roof. They are particularly beneficial for homes needing more headroom and floor space than a Velux conversion can provide.

The cost of a dormer loft conversion typically starts from around £30,000 to £60,000, depending on the size and complexity of the project.

Small loft conversion of 20 m2 typically costs £30,000 to £35,000, while 30 m2 mid-range dormers would be priced from £40,000 to £45,000. A larger-scale 64 m2 loft conversion with a double bedroom and en suite could cost anywhere from £45,000 to £50,000.

The price will also depend on the type of dormer you choose. Below we described the average conversion costs for a middle-sized 30 m2 loft based on the dormer type:

The construction might take around 8-12 weeks to complete.

Dormer conversions require building regulations approval to ensure they meet safety and construction standards. Planning permission may not be necessary unless the property is in a conservation area or the conversion falls outside certain limits and conditions.

Hip to gable loft conversion involves the extension of the sloping 'hip' side of a roof into a vertical 'gable' end, creating more space within the loft. This type is more complex due to the structural roof changes required but is effective in maximising the available space under the roof.

This type is ideally suited for detached and semi-detached loft conversions or bungalows with hipped roofs. These properties have at least one sloping side that can be extended into a gable end to maximise the internal loft space.

The cost for a hip to gable loft conversion typically ranges from £40,000 to £60,000, depending on the project's complexity and the materials used.

For a simpler version of this conversion with standard finishes the cost per square metre is typically between £1,250 to £1,450. Premium materials and bespoke features can push costs from £1,750 to £2,000 per square metre.

The construction period can vary but usually takes between 6 to 8 weeks to complete.

Building regulations are necessary for a hip to gable conversion to ensure that the structural alterations are safely implemented. Planning permission may be required, especially if the property is in a conservation area and since the conversion alters the roof's shape significantly.

A mansard loft conversion is considered the most comprehensive and typically the most expensive type. It involves altering the structure of the existing roof to create a nearly vertical 72-degree slope, with the remaining top of the roof flat.

This conversion significantly changes the roof's shape and can almost add an entire new story to a property.

Mansard conversions can be a great option for a wide range of property types, including terraced, semi-detached, and detached house loft conversions. They are particularly popular in urban areas where maximising living space within the existing footprint of a building is essential.

The cost for a mansard loft conversion usually ranges from £45,000 to £70,000. The price per square metre starts from approximately £1,500 to £2,500. The wide range in costs reflects variations in material choices, the complexity of the build, and regional differences in labour rates.

The project duration can vary but typically takes between 6 to 8 weeks to complete, depending on the complexity and scale of the conversion.

Mansard conversions almost always require planning permission due to the significant changes in the roof's structure and property silhouette. Building regulations approval is also needed to ensure the conversion meets all safety, insulation, and accessibility standards. These regulations ensure that the new space is safe, efficient, and comfortably habitable.

Modular loft conversions consist of prefabricated units that are constructed off-site and then installed onto a property. This process involves removing part or all of the existing roof and replacing it with the premade loft module.

This method is highly efficient and minimises the time spent on construction at the property.

This can lead to reduced energy consumption and lower heating costs.

Modular conversions are suitable for a wide range of properties, including detached, semi-detached, and terraced houses.

They are particularly beneficial for properties with limited space around them for on-site construction activities or in areas where construction noise and disruption need to be minimised.

However, for mid-terraced homes, which are situated between two other homes sharing walls on each side, the feasibility of modular loft conversions may be more complex. Mid-terraced houses don’t have the option to extend to the side. But a rear extension or a front extension could be a viable possibility to extend your mid-terrace house.

These properties require careful assessment to determine if a modular conversion is possible, considering the unique challenges of installing prefabricated units in such a constrained space.

The cost of modular loft conversions can vary widely depending on the size and specifications of the module but typically ranges from £50,000 to £75,000. Costs per square metre typically range from approximately £1,800 to £2,500

This pricing accounts for the prefabrication of the loft module, transportation to the site, and installation, including any necessary modifications to the existing structure to accommodate the new module.

The installation process is relatively quick. The off-site construction of the module can take from 6 to 12 weeks, but the on-site installation is usually completed within 1-2 days.

Like all loft conversions, modular conversions require compliance with building regulations to ensure they meet safety, energy efficiency, and design standards. Planning permission may also be necessary, especially if the conversion alters the external appearance of the house.

Bungalow loft conversions involve transforming the attic space of a bungalow into livable space. This can significantly increase the living area of a bungalow, which is often limited by its single-storey layout.

The conversion can include adding dormer windows or altering the roofline to increase headroom and natural light.

This conversion type is ideally suited for bungalows with adequate attic space to be converted into habitable rooms. The suitability also depends on the existing roof structure and the potential for modification to accommodate the desired living space.

The cost for a bungalow loft conversion can vary significantly based on the complexity of the project, starting from around £30,000 to £60,000.

Costs per square metre can range from approximately £1,200 to £1,800. This variation accounts for factors such as the complexity of the roof alterations, the quality of materials, and the desired finishes.

The duration of the conversion process can range from 6 to 12 weeks, depending on factors such as the extent of structural modifications and the finishes required.

Building regulations approval is required for bungalow loft conversions to ensure the new living space is safe, accessible, and energy-efficient.

Planning permission might be needed depending on the extent of the changes to the roofline and the property's location, especially if it's in a designated area or if the conversion involves significant alterations to the external appearance of the bungalow.

Choosing the right loft conversion for your home requires a thoughtful examination of various essential elements. It's crucial to select a conversion that matches your property's unique features, meets your specific requirements, and fits within your financial plan.

The architectural style of your home plays a pivotal role in determining the most suitable loft conversion type.

Whether your home is detached, semi-detached, or terraced, the property type can dictate the structural possibilities and limitations.

For instance, a mansard conversion might be more suited to terraced houses in urban areas. Mansard loft conversion on a terraced house is a very popular choice due to its significant space optimisation. On the other hand, a hip to gable conversion could be the go-to choice for detached or semi-detached homes with a sloping roof.

If you are not sure what type of conversion is suitable for your house, you can consult with an architect.

Your budget is undoubtedly one of the most crucial considerations. Different types of loft conversions come with varying price tags, from the more cost-effective Velux conversions to the more expensive mansard and modular options.

The selection of finishes, the decision to include a bathroom, and other such additions can significantly impact the overall cost. Therefore, we advise to establish a realistic budget that includes a contingency of 10-15% to accommodate any unforeseen expenses.

It's essential to factor in not only the initial construction costs but also potential energy savings over time, as some conversions offer greater opportunities for enhancing energy efficiency.

The current design and structure of your roof will significantly influence your conversion options. Some properties may not accommodate certain types of conversions without extensive structural modification.

Furthermore, local planning restrictions can play a crucial role, especially in conservation areas or for properties with specific historical value. Always check with your local planning authority to understand what modifications are permissible.

Sustainability is an increasingly critical factor in choosing a loft conversion. Consider how to optimise each conversion for energy efficiency. This can include adding high-performance insulation and energy-efficient windows. Also, consider adding renewable energy sources like solar panels.

Sustainable conversions not only reduce your carbon footprint but can also lead to significant savings on energy bills.