How to design and build your own home?
You want to build your house at the best price ?
Construction Guide offers to detail all the key moments in the construction of your home. Our full guide explains what are the steps to follow as well as the tips to carry out your project.
Define the project and the budget
Define its borrowing capacity
When you want to build your home, the first step is to determine your borrowing capacity. Evaluate precisely the maximum amount that you can borrow according to the income of your household, your contribution if you have one and your expenses.
The borrowing capacity is calculated according to multiple criteria: the debt capacity, the amount of your personal contribution, the amount of the desired monthly payments, the type of loan, the duration of the loan and the age of the borrower. To quickly and simply determine your borrowing capacity, we provide you with a dedicated calculator.
By calculating your borrowing capacity, you will be able to consider a project that is more specifically suited to your budget.
Ensure that the project is properly and legally feasible
In the municipality where you wish to settle, the town hall will be able to inform you about the buildability and the conditions of servicing of your land. You will be able to consult the local urban plan (PLU) and request an operational town planning certificate.
Not all land is buildable. But it is always possible to file a request for modification or revision of the local urban plan with the town hall of the commune where you wish to build. If there is no natural risk (flood, avalanche, landslide) on the plot in question, you have more reason to hope to be able to make a building ground. The plan for the prevention of foreseeable natural risks (PPRN) in the appendix to the PLU can indeed prohibit constructions.
The law now makes soil study compulsory. It is the seller’s responsibility to provide this geotechnical study as an annex to the promise to sell. The measurement ensures the stability and sustainability of the house. A way to avoid cracks, infiltrations or even differential settlement.
To build a detached house, you can call on prime contractors (of which the architects are part) or builders. However, the types of contracts that each offers offer very different guarantees of which one must be aware when choosing. Unlike the contract for the construction of individual houses (CCMI) which is regulated by the law of December 19, 1990, the contract for the control of works (CMO) is only regulated by a standard. The final price of the works and that of the services not included are not specified in the CMO. While the CCMI proposed by the manufacturers engages their responsibility and guarantees in particular the completion of the construction (even in the event of bankruptcy) at the agreed price and deadline.
With the individual house contract , the manufacturer sells you the product that is the house produced. You pay him the full bill for your future home. The CCMI is more suitable for standardized houses.
The master’s (or architect) contract is more of a service contract where the designer is independent but in relation to the artisans who make the house. In this case, the prime contractor represents you, advises you and defends you if necessary. The CMO will sometimes have the advantage of being more competitive for personalized homes.
Imagine the construction project
You can now sketch the plans of your house, imagine the number of rooms and rooms you want, their approximate layout and the overall style of the house. If desired, an architect or decorator can contribute to this step.
Also determine if you want a home on one level or with floor. Perhaps you also want to add a garage or cellar ?
Estimate the cost of construction
In general, there are approximately between 1,200 and 2,000 € / m² for a construction of a single house. But it also depends on the manufacturer’s service rate.
Depending on the area, layout and materials you have determined previously, you can estimate a fairly wide price range for your project. Be aware that certain construction options such as choosing a floor house or a flat roof can increase the price per square meter.
Tariff table according to construction method
|By a manufacturer||1,349 euros|
|By a masterpiece||1,445 euros|
|In self construction||1,505 euros|
|By an individual||1,557 euros|
|By an architect||1,847 euros|
Construction cost table
|Thermal study||400 to 500|
|Surveyor (born)||1000 to 1500|
|Field connection||1000 to 3000|
|Building permit||1000 to 5000|
|Floor covering||50 to 300 euros / m²|
|Field||134 euros / m²|
|Individual house||1200 to 2000 euros / m²|
|Notary||7 to 8% of the total price|
|Work damage insurance||7 to 8% of the total price|
|External developments||7 to 10% of the total price|
|Construction professional fees||8 to 12% of the total price|
Find your land
This step is crucial because finding land will allow you to determine where you are likely to build your home. The first criterion for choosing land often remains its price. The latter can vary from simple to double between two separate municipalities of a few kilometers.
It is also up to you to determine whether you wish to live in a subdivision or on a more isolated ground. In addition to the journey to the workplace to be taken into account, it is interesting to verify that services such as shops, schools or means of transport are nearby. A nearby and permanently established station or school may be useful.
Viable land will only require funding for the connection at the edge of the plot. If you choose a diffuse ground, all connection work will be at your expense.
If the land is sloping, this will involve earthworks costs for your construction. But some may find charm in the reliefs instead of favoring a flat ground which is certainly easier to build.
According to the municipality, the low price of land can sometimes hide a high housing tax and a property tax. So check the amount of local taxes.
Be aware that notary’s costs relate only to the land and not to connections or the construction of the house. They mostly represent between 7% and 8% of the sale price of the building land.
The demarcation and surveying of your future land prevents possible disputes by delimiting your plot exactly. We advise you to ask the seller for specific plans made by a surveyor.
Design your home
Choose a construction professional
When you want to build your house, it is strongly advised to call on a professional in the sector, whether he is a house builder, architect or prime contractor. If your house is over 150 m², the law requires the presence of an architect for the rest of the project.
You can check the reputation of the manufacturer, on the internet, social networks or more simply word of mouth with professionals as well as individuals. Or even make direct contact with those who interest you in order to have more information on their working methods, the overall quality of their homes and the materials they use. If possible, compare the constructions already carried out by the manufacturer, both in terms of the quantity and the quality of the buildings.
The AAMOI (Individual Works Council) top builder can help. It identifies the manufacturers of houses often pinned for irregularities in the construction contract.
Please note, there may be large differences depending on the work operators of the same construction group. In addition, manufacturers sometimes have their own web information sites. We must therefore be wary of their bias.
Small artisans can be as serious in monitoring their sites as large manufacturers. Even if some salespeople from these large entities sometimes claim the opposite.
Before definitively choosing your manufacturer, we strongly advise you to request quotes and compare them in order to determine which professional is most suited to your budget. If many are, know-how and building materials can help you make the most meaningful choice.
Design your home plans
At this stage you are ready to draw the plan of your house according to your desires and your needs. Choose the number of rooms, if there will be floors and the general style of the house.
Please note, depending on the municipality where you wish to build, certain construction constraints may apply. It is important to learn about the PLU (local urban plan) in force in the municipality concerned. This is to verify the conformity of your project with the constraints imposed.
The manufacturer you have chosen may then be able to present the 3D plans of your home so that you can project yourself more realistically into your future home.
Deposit the building permit
The request for a building permit should be sent to the town hall of the town where the construction will be located. This request consists of various documents, including construction plans. The response from the town hall may require approximately 2 months. The delay may be longer if construction is envisaged in a particular sector (areas of historic monuments, parks and natural reserves in particular). Remember to attach to your permit application to build the mandatory RT 2012 thermal regulation certificate.
If the building permit is issued, it will be valid for a period of 3 years. Two 1-year extension requests can be made for even more time.
In case of refusal, you can request a new examination at the town hall or possibly modify your initial project.
When entrusting the construction of your house to a manufacturer, the latter can take care of the deposit of the building permit for you. We nevertheless advise you not to delegate your signature to it. If the procedures will last a little longer, you will personally receive the possible objections and may communicate them to the manufacturer. If you delegate the signature to the manufacturer, in case of error, the costs will be borne by you.
The construction site
When you choose a manufacturer for your home, several site meetings are scheduled and take place at each invoice payment according to a schedule defined by law:
- 15% at the start of the site
- 25% at the end of the foundations
- 40% after the walls rise
- 60% when fetching
- 75% when venting
- 95% upon completion of equipment, plumbing, carpentry and heating
The remaining 5% is paid upon receipt of the work.
These site meetings are important. They allow you to check the good progress of the works and to ensure that the site complies with what was planned at the start.
The structural work
Earthworks and foundations
The earthworks consists of leveling the ground and making the trenches in order to be able to set up the connection with the water, electricity, gas and telecommunications networks. These works last more or less long depending on the nature of the soil. They are more easily carried out during the dry period and are easier when the soil is compact.
The foundations allow the house to be perfectly stable on the ground. Different foundation techniques are used depending on the nature of the soil, the materials and the heaviness of the construction.
This part of the structural work consists in allowing the evacuation of waste water (from the toilet, the kitchen or even the bathroom). These waters can be treated by the community via sewers or individually through a septic tank.
The basement represents the part between the foundations and the ground floor of a house. There are different types:
- Full earth: this is the most economical solution; here the floor of the house rests directly on the foundations.
- Basement: the cost is higher but allows you to benefit from a larger living space.
- Health vacuum: it allows to leave a space between the foundations and the ground and very well protects the constructions of the infiltrations of humidity.
This is the floor of the house. It will support the loads on each construction floor. There are two kinds:
- The low floor, built on the foundations of the house.
- Intermediate floors which are worn by a structure carried by one of a cast concrete slab or a beam system.
The construction of the walls
The elevation of the walls allows the house to take shape. The location is reserved for the various openings (doors and windows) as and when built. The walls can be constructed from different materials: stone, brick, concrete block or even wooden according to your preferences.
The frame and the roof
The frame supports the weight of the roof and must resist any additional loads in the event of bad weather (rain, ice, snow). There are three types of frame: the traditional frame, the industrial (or closed) frame and the flat roof frame.
Once the frame is finished, the roof that can be of different nature is laid depending on the local urban plan, the regions or its usefulness. We can also, for example, consider green roofs or solar roofs composed of thermal or photovoltaic panels.
Once this step has been completed, the house is considered to be out of water.
The installation of carpentry (windows, French windows and doors) allows the house to be put out of the air. This stage generally announces the end of the structural work and the start of the second work aimed at making the house habitable.
The second work
The electrician and the plumber intervene in order to set up the various equipment essential for the proper functioning of your installation of water and electricity.
The installation of the various ventilation systems makes it possible to always keep healthy air in the house and contributes to the reduction of the humidity of the house.
Thermal and sound insulation will allow you to live in peace in your home.
Choosing the type of insulation will also have an impact on your expenses related to the temperature of your home. The more a house is well insulated, the lower the cost of heating or air conditioning. And you will be able to benefit from a temperature regulated throughout the year.
Partitioning and coatings
The interior partitioning of your house will allow the construction of the various rooms. It will ideally be done with materials adapted to the uses of the parts concerned. For example, the material of the bathroom partitions must be water resistant.
Also installed are interior carpentry composed of doors but also baseboards.
The installation of different coatings on the floor and on the interior walls signs the close end of the second work.
The handing over of the keys
The time of handing over the keys allows you to verify that all the work ordered has been completed.
In case of non-compliance, you can report it in the acceptance report. If everything is in order and you accept your house as is, you will have 8 days left to pay the remaining 5% to the builder of your house. Even after signing and handing over the keys, you will have 8 days left to report a reservation regarding the work.
You can be accompanied by a construction professional when handing over the keys, in order to more easily identify certain faults. We recommend never accepting the presence of the expert chosen by the manufacturer because they are sometimes in cahoots between them. Instead, be assisted by a bailiff. And, to make an inventory of any elements to correct, you can request an architect. It is often better to pay the fees of these experts to have peace of mind. However, be aware that, if you are accompanied by one of these professionals, you will not be able to benefit from the 8 days of time to express your possible reservations.
Remember that a second RT 2012 certificate is required to prove that your finished construction meets these standards. The declaration attesting to the completion and conformity of the works (DAACT) is also compulsory in order to notify the town hall of the end of your work.
Once at home, the finishes remain at your expense and allow you to customize and decorate your interior as you see fit. You will generally have to perform certain work not taken care of by the manufacturer, such as the installation of the kitchen or that of the rolling shutters.
Remember that the layout of outdoor spaces is also your responsibility and can be done by a craftsman or by yourself depending on the remaining budget.
Manufacturers fail to mention that a certain number of works remain the responsibility of the buyer upon delivery. What remains to be done can be expensive. Read the instructions in your contract carefully, the adjustments which are not specified to be at your expense and those whose expense is not quantified are the responsibility of the manufacturer.
Get a good mortgage
Obviously, start by looking at the borrowing rate and the duration of your credit. Try to compare the different types of loans you can get. Feel the ground to try to lower or cancel folder fees.
Be well insured
With insurance, the dilemma is to get the lowest rate while keeping the maximum of guarantees. It’s up to you to determine or place the cursor without cutting too much on your guarantees, all the same. In fact, be sure to carefully define the end date of the guarantees.
Play the competition
Competition between manufacturers or prime contractors facilitates discounts or rebates. These professionals certainly want the construction project to bring them back, but they can also be ready to align with the prices of their colleagues or even to stand out from them.
Avoid building without a plan
The plan of a house cannot be improvised if we want to avoid future harassment. Better to entrust this to a professional. Thus, you will surely avoid miscalculations, poor forecasts of materials and materials, possible fines and ultimately an exploding budget.
Precautions on control houses
Beware of certain control houses because it is sometimes necessary to pay more for having certain materials or equipment seen during visits. It is better to consult the document which lists the materials of the house model in question carefully. If there are elements from the control house, raise them to obtain possible concessions on prices or products, or even the replacement of the elements in question by the manufacturer. That said, it must nevertheless be noted that the control houses very often remain very competitive offers in terms of value for money.
Take care of the theft
The equipment and materials used for the work are coveted by certain thieves. We recommend that you, if you can afford it, put your site under surveillance. Put what you can in an ideally locked place, or at least out of sight. Even if you have insurance, this kind of misadventure can still cost.
What help can you get ?
You can benefit from premiums, loans at reduced rates and exemptions in certain municipalities or by certain organizations. Tax benefits are granted in particular to promote insulation works. The town hall of your commune, the departmental council, the National Agency for Information on Housing (ANIL), the National Agency for Housing Improvement (ANAH) or the Environment and Energy Management (ADEME) will be able to inform you about this.