How to Convert Your Attic Step by Step ?


Optimizing Loft Space is a project that brings freshness to your home. Do you have unused attic space? Know that this overlooked space, a significant source of thermal loss when poorly insulated, can be transformed into a real asset. Indeed, it is possible to create an additional room there (guest room, children's room, master suite, playroom, bathroom, office, living room, terrace...) after some work. Moreover, these few square meters under the roof represent a significant added value at a lower cost. Furthermore, since this operation always involves insulation work, you will achieve notable energy savings. Discover all the key information for a successful loft conversion.

Focus on the essential points to check when renovating your attic.

Before engaging a specialized company, you must verify whether your attic is suitable for conversion. For this, several points need to be examined before starting the project.

Minimum Geometric Characteristics

Firstly, if the ceiling height is insufficient, you won't be able to convert your attic. It must not be less than 1.8 meters for them to be considered habitable. Also, a roof pitch greater than 35° is required, with 45° being ideal. It also depends on the nature of the frame. If it's a traditional frame, and there's sufficient space available, the conversion won't pose any major difficulties.

However, in a trussed structure, the type of trusses used (wood or metal) determines the feasibility of the operation. In any case, your house's frame must not encroach on the floor. Moreover, since the latter will support the weight of the conversion, it must be load-bearing and stable enough. Consider the insulation materials, furnishings, and any partitions. Thus, reinforcement may be necessary depending on the nature of the existing floor.

Municipal Policies

You'll also need to inquire about your municipality's policies. Check if the local urban development plan (PLU) allows you to carry out such a project. Additionally, ensure from the outset that the future construction complies with the current urban planning regulations.

The third-party recourse right is, among other things, an essential point to consider. Your neighbors have two months from the date of posting the declaration or permit to contest the work (especially if the operation involves creating a window overlooking a neighboring house or apartment). Furthermore, if you live in a condominium, it's mandatory to inform the homeowners' association of such a project.

The process to undertake for loft conversion

When considering converting your attic, it's highly advisable to inquire with the town hall of your municipality. There, you'll find all the information regarding the formalities to follow and the assistance available to you for this operation.

In principle, if the area to be converted is between 5 and 20 square meters, a prior declaration of works (DP) is required. However, you'll need a building permit if the area exceeds 20 square meters (40 square meters when the municipality has a PLU). Moreover, the intervention of an architect is imperative for an area exceeding 170 square meters.

Works Required for Attic Conversion

There are several operations to carry out to convert your attic into comfortable and functional living space.

Access to the Attic

In most cases, unconverted attics have nothing more than a simple hatch for access. If you wish to convert them, you'll need to install safe and easy access. Moreover, it must allow for easy transportation of your furniture. In this case, the choice of stairs depends mainly on the use of the space after conversion and especially on its level of traffic.

If it's a room you occasionally visit (for example, a playroom or a guest bedroom), a narrow staircase will suffice. However, for heavily frequented rooms, such as the living room, bedroom, or bathroom, you'll need a sufficiently wide model. In any case, if space is lacking on the lower floor for adding a real staircase, a ladder or a retractable staircase should be preferred.

Priority to Insulation

Insulation can be carried out either from the inside or from the outside.

Interior Insulation

Interior insulation is less expensive. However, it results in a loss of space due to the thickness of the thermal insulation. First and foremost, ensure that the roof is perfectly waterproof. Then, apply two crossed layers of insulation. To better protect the insulation against moisture, the roof should be covered with a waterproof membrane on the inside and a rain screen on the outside.

In terms of insulation, you have a choice between glass wool, rock wool, expanded polystyrene (EPS), polyurethane foam, thin insulation, etc. These products all have good performance. The difference lies mainly in their ease of installation and price.

Rock wool and glass wool are the most common and expensive. Moreover, they respond well to the new thermal and acoustic regulations. Available in rigid and semi-rigid panels or flexible rolls with or without a vapor barrier, these mineral-based insulators adapt well to the different dimensions between trusses and rafters.

For finishing, it's possible to cover the rigid face with paper or paint it. Polyurethane and expanded polystyrene foams in the form of rigid panels have very high thermal and acoustic performance. Lightweight and rigid, they cut easily with a standard tool, such as a jigsaw or handsaw. Moreover, they are non-compressible and comply with the latest insulation requirements. However, these products are expensive.

Exterior Insulation

This option allows for optimal insulation. In fact, it's ideal if you want to preserve the available space in your attic. Unfortunately, external thermal insulation is only possible as part of a major project that can lead to the overhaul of the roof. Thus, if you plan to renovate your house's roof, don't hesitate to insulate your convertible attic from the outside. However, note that this type of operation must be entrusted to a specialist in the field.

Regardless of the technique used, know that attics can only be habitable when properly insulated. This operation aims above all to ensure a level of comfort similar to that of other rooms in the house in both winter and summer. At the same time, you reduce heat loss through the roof (about 30%) and thus achieve energy and heating cost savings.

Installation of Heating and Electricity

The installation of heating and electricity is also another significant step in attic conversion works. For heating, you can either connect to the central heating circuits or opt for independent electric heating.

For electricity, the simplest option is to set up a secondary panel connected to the main panel. It's also possible to install independent electrical wiring. However, this solution is more expensive.

Other Finishing Works

To better illuminate the converted attic with natural light, one or two openings should be planned. This also allows for more effective ventilation of the room when it's hot, especially during the summer season. In this case, prefer roof windows to conventional windows for more brightness. A glazed area equivalent to at least one-sixth of the habitable area is then necessary.

To avoid shadow areas, it's better to opt for two small windows on either side of the convertible attic rather than a large central bay. Ensure they are evenly distributed on both sides of the roof to optimize ventilation. Windows have the merit of bringing free heat from the sun in winter. However, they can cause overheating on sunny days. Therefore, it's necessary to invest in exterior sun protection or roller shutters. The latter are also useful in combating cold.

Don't forget to lay an acoustic underlay under the floor covering to reduce footstep noise.


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The budget to plan for attic conversion

Budgeting for attic conversion can vary depending on several factors, including:

  • Initial condition of the attic,
  • complexity of the renovation,
  • area to be converted,
  • roof structure (trusses or traditional),
  • type of room to be created (bathroom, office, master suite, guest room, children's room, playroom, etc.),
  • cost of labor,
  • type of insulation to be used

To give you a more precise idea of the budget required, here are the estimated costs for each aspect:

  • Roof structure: €500 to €1,500 per square meter,
  • Insulation: €35 to €70 per square meter,
  • Staircase: €500 to €3,000,
  • Electrical installation: €50 to €100 per square meter,
  • Plumbing for water access: €1,500 to €6,000,
  • Windows: €150 to €6,000,
  • Partitions: €35 to €60 per square meter,
  • Finishes: €10 to €50 per square meter

For a more accurate estimate, don't hesitate to consult a renovation professional like Reno.

State Aid for Attic Conversion Works

Attic conversion projects are eligible for various state aid programs :

The CITE (Energy Transition Tax Credit)

This replaces the former eco-tax credit and applies to any energy renovation project on the main residence. With this fiscal mechanism, you can deduct 30% of the expenses incurred from your income tax. The financing amount is capped at €16,000 for couples and €8,000 for single individuals, with an additional €400 for each dependent.

Government subsidies and financial aid

The CITE can be combined with other government subsidies and aids, such as reduced VAT, interest-free loans, and grants from the National Housing Agency (ANAH).

Reduced VAT

You may qualify for a reduced VAT rate of 5.5% (instead of the standard 20%) if you hire a professional for your project. This rate applies to both labor and material costs for insulation.

Eco-friendly interest-free loans

Through this program, you can obtain a loan of up to €10,000 for roof and attic insulation projects. However, not all banks offer this service, and you must hire an RGE-certified (Recognized Guarantor of the Environment) company to be eligible.

ANAH grants

The National Housing Agency provides financial assistance to individuals for improving the energy performance of their homes. The "Better Living" program offers financing of up to 50% of the total project cost, capped at €10,000, with an additional grant of up to 10% of the work cost (maximum of €2,000).

Optimizing Loft Space

Converting your attic: the importance of using a specialist

Attic conversion involves multiple trades, including carpentry, plumbing, architecture, electricity, and masonry. Therefore, it's best to hire a renovation specialist like Reno. If you want expert advice and practical ideas for optimizing your attic space, feel free to contact us.

Attic conversion must be carefully studied, taking into account various elements such as ceiling height, the possibility of adding roof windows for natural lighting, and the current attic structure. Before starting the renovation work, a prior declaration to the competent authority, usually the local urban planning department, is required. This administrative step is essential to ensure that the project complies with current regulations, including local urban planning and attic conversion plans. Furthermore, the habitable surface area of the convertible attic must be evaluated, considering the constraints related to attic insulation. It is also crucial to inquire about qualified artisans and ensure they comply with the standards and regulations outlined in the attic conversion project. A planning permission may be required, especially if you plan external modifications such as adding roof windows. Therefore, the successful completion of an attic conversion project depends heavily on a thorough understanding of local urban planning regulations, attic surface area, and specific attic conversion work requirements. The prior declaration of works is an essential step, and collaboration with qualified architects is essential to ensure project compliance with urban planning regulations when converting attics. 

In summary, hiring a specialist is much more than a precaution; it's a guarantee of success for attic conversion compliant with standards.

Analyzing the technical feasibility of the project 

The conversion of attic space must be meticulously examined, taking into account various elements such as:

  • Ceiling height;
  • the possibility of adding roof windows for natural lighting;
  • and the current structure of the attic.

Before commencing the conversion works, a prior declaration to the competent authority, usually the local urban planning office of the municipality, is necessary. This administrative step is essential to ensure that the project complies with the current standards, including the local urban planning regulations and the attic conversion plan. Subsequently, the convertible attic space must be assessed in terms of potential habitable surface area. This involves considering the constraints related to the insulation of the converted attic. It is also crucial to inquire about qualified artisans and ensure that they adhere to the standards and regulations outlined in the attic conversion project. A request for urban planning authorization may be necessary, especially if you are considering external modifications, such as adding roof windows. Thus, the successful realization of an attic conversion project depends closely on a thorough understanding of the local urban planning regulations, the attic surface area, and the specific requirements of the attic conversion works. The prior declaration of works is an essential step. And collaboration with qualified architects is essential to ensure the project's compliance with the current urban planning standards when it comes to attic conversion.

Conceptualization and Design

Do you want to convert your attic but lack ideas? Discover our tips for design and conception for a renovation that meets your expectations! 

Choice of Interior Architecture 

The choice of interior architecture for attic conversion is crucial and must align closely with the intended use of these transformed spaces. Ceiling height and conversion work constraints can guide this decision, determining the potential for attic conversion. Every square meter of habitable space must be considered a valuable resource, and the interior architecture should be designed accordingly.

Attic insulation is also a key element, influencing not only thermal comfort but also room layout. A well-defined prerequisite for the work, including compliance with urban planning authorization standards and roof windows, will guide architectural choices. The aesthetic aspect of attic conversion projects must harmonize with local urban planning and attic conversion plans, ensuring successful integration into the urban planning of the municipality.

The choice of interior architecture must consider luminosity, with particular attention to roof windows that provide a natural light source. The superior roof slope and ceiling height are architectural features that can be creatively exploited to optimize space and create unique atmospheres.

Selection of Materials and Decorative Elements

The selection of materials and decorative elements is also a crucial step in attic conversion, where each choice contributes to the overall aesthetics and functionality of the transformed spaces. Faced with height constraints and conversion work imperatives, it is imperative to opt for lightweight materials that provide a sense of openness, thus optimizing the available habitable surface area.

 Tips and Techniques

To optimize the outcome of your attic renovation, here are some tips and techniques recommended by our architects!

Thermal and Acoustic Insulation for Comfortable Attics

Thermal and acoustic insulation is a crucial aspect of attic conversion. Faced with challenges such as ceiling height and conversion works, selecting high-performance insulation materials is imperative to maximize the usable space while ensuring effective insulation.

Attic insulation is not just a technical necessity but also a step toward enhancing occupants' well-being. Prior declarations and urban planning permits guide the standards to be adhered to in this area, framing choices related to attic conversion projects. Roof windows are sensitive points requiring special attention during insulation to prevent heat loss. The expertise of a qualified artisan in roofing is invaluable here to ensure proper implementation, aligned with local urban planning regulations and attic conversion plans.

The acoustic aspect of insulation is equally important, especially in attic renovations. The steps involve integrating materials that minimize noise propagation, ensuring tranquility in the house. Detailed simulations for attic conversion works allow for anticipation of thermal and acoustic insulation performance, adjusting the attic conversion cost accordingly.

Natural and Artificial Lighting Solutions

Incorporating natural and artificial lighting solutions is a crucial step in attic conversion, aiming to create bright and pleasant spaces. Faced with constraints like ceiling height and conversion works, maximizing natural light becomes a priority to optimize usable space and foster a welcoming atmosphere.

Roof windows play a central role in creating natural brightness. This choice is guided by technical considerations related to attic insulation, as well as regulatory aspects, requiring prior declaration and possibly urban planning authorization. A successful attic conversion project must integrate these elements while adhering to the standards of local urban planning and the attic conversion plan of the municipality.

In addition to natural lighting, artificial lighting must be carefully planned. The attic conversion steps include selecting fixtures suitable for ceiling height and space configuration. The expertise of a qualified roofing artisan is essential to ensure optimal installation, fitting within the framework of attic renovation and conversion. Simulations for attic conversion works help refine choices, considering both storage efficiency and attic conversion prices.

In summary, lighting solutions are a key element in the success of attic conversion, merging functionality and aesthetics. The balance between natural and artificial light is part of administrative procedures, including prior declaration forms. A meticulous approach to these elements not only ensures optimal use of space but also contributes to the real estate value of the house with attic conversion. Thus, lighting becomes a strategic component, contributing to the creation of a harmonious and functional environment.

Optimization of Storage to Maximize Space

Optimizing storage is an essential step in attic conversion, allowing for maximum use of available space while preserving interior aesthetics. Faced with constraints such as ceiling height and conversion works, every square centimeter of usable space must be strategically exploited.

Convertible attics pose specific challenges in terms of storage integration. Incorporating these solutions requires careful consideration, aligned with the standards of prior declaration and urban planning authorization. Roof windows can offer creative opportunities for integrating clever storage solutions, but their placement must respect the attic conversion project and the guidelines of local urban planning and the attic conversion plan of the municipality.

The expertise of a qualified roofing artisan is crucial in designing custom storage solutions that adapt to ceiling height and roof slope. These elements must be designed to facilitate attic conversion steps, harmoniously fitting within the framework of your attic renovation. Simulations for attic conversion works refine choices, considering both storage efficiency and attic conversion costs.

Real Estate Valuation 

Did you know that converting your attic contributes to a certain form of real estate valuation? Let's explain! 

Impact of Attic Conversion on Property Value

Attic conversion has a significant impact on the value of a property, combining both an increase in usable space and aesthetic enhancement. Faced with constraints such as ceiling height and conversion works, the potential to transform convertible attics into habitable spaces offers an opportunity to optimize usable space. This directly translates into added value for the property.

Implementing attic insulation, necessary for thermal comfort, also aligns with a valuation logic. Administrative procedures such as prior declaration and urban planning authorization are key elements guiding the project. Roof windows, in addition to their functional role, contribute to the overall aesthetics, thus reinforcing the aesthetic value of the property. 

In summary, attic conversion is not just about optimizing space; it is also a smart strategy to increase real estate value. This transformation, when well-planned and executed, represents a profitable investment. 

Tips for Optimal Presentation When Selling

For optimal presentation when selling a property with an attic conversion, several strategic tips can be implemented to attract potential buyers. This will draw attention to the property's distinctive features. First and foremost, highlight the conversion of convertible attics into habitable spaces. This involves emphasizing the maximization of usable space achieved through conversion works.

Additionally, attic insulation becomes a significant selling point for thermal comfort, something to highlight during visits. Presenting administrative procedures, such as prior declaration and urban planning authorization already completed, assures future owners of a smooth transition to an already approved project. All while considering the standards of the local urban planning and the attic conversion plan of the municipality. The quality of roof windows becomes a focal point, underscoring the expertise of qualified artisans involved in attic conversion works. 

In summary, for optimal presentation when selling, it is essential to highlight the distinctive features of attic conversion. To enhance the property's appeal, emphasis should be placed on:

  • Energy efficiency through attic insulation,
  • Approval of administrative procedures,
  • And the quality of the attic conversion transformation.

Skillful communication about the works positions the property as an attractive investment, thus amplifying its potential during attic conversion.

Current Trends in Attic Conversion

Facing the challenges of ceiling height and conversion works, creating converted attics is becoming an increasingly popular choice. And for good reason, attics offer a natural extension of living space. They also satisfy the quest for additional square meters.

In the midst of all this, attic insulation emerges as an essential trend. To achieve this, our architects integrate high-performance materials to ensure maximum energy efficiency. 

Convert Your Attic with Reno!

In conclusion, attic conversion emerges as a both rewarding and complex endeavor. Therefore, it is in your best interest to have professional guidance. Ceiling height and conversion works may be seen as challenges. However, they become opportunities under the guidance of our specialists. Indeed, transforming convertible attics into functional living spaces requires a thorough understanding of insulation standards and regulations related to prior declaration. It also requires an artistic vision to maximize usable space while preserving aesthetics.

In summary, choosing the support of an architectural agency in the field of attic conversion is the key to a successful experience. So, do not hesitate to contact us now to discuss your project and get a quote!

Mathieu Amara

Mathieu Amara

Graduated in political science, I have always been passionate about renovation and construction work.

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