The total price of a new house is often not known precisely before the construction project begins. Indeed, the house price displayed by the builder does not reflect the actual costs required to complete the project. Under these conditions, how plan your budget Overall? Land, notary fees, taxes, insurance, studies, utility connections, landscaping, layout… In the end, 10 to 20% of the house construction budgetis dedicated to additional costsWhat are these costs? How can they be reduced? Maisons Sic, builder of individual houses in the Southwest helps you take stock.
The costs associated with purchasing the land
Average price of a building plot in the Southwest
Le average price of land in the Southwest is €64/m2 in New Aquitaine for €83/m2 of land in OccitaniaThis average obviously does not reflect the reality of the market in the Southwest and its enormous disparities from one particular sector to another: attractive cities like Bordeaux, Toulouse, Bayonne, Tarbes or Pau, the appeal of the coastlines Atlantic or Mediterranean with cities like Arcachon, Biscarrosse ou Saint-Jean-de-Luz, Narbonne ou Perpignan
Real estate agent fees
While typically paid by the land seller, agency fees are ultimately borne by the buyer since they are included in the sale price. These agency fees are not fixed; they can be a fixed amount or a percentage of the sale price. Therefore, the choice of real estate agency has a significant impact on the overall cost of a new house.
Transfer fees or notary fees
Due during each real estate transaction, the acquisition feecommonly called notary feesThese include: the land registration tax (TPF), fees and disbursements, and the notary's fees. For a building plot, it is generally estimated that all of these costs represent 7 to 8% of the purchase priceTo estimate the costs of a project, access here at the acquisition cost simulator developed by ANIL, the National Agency for Housing Information.
Total cost of a new house: what are the site preparation costs?
Some plots of land are not serviced. This means that the connection to networks (Water, electricity, sanitation, etc.) must be installed before any construction. The cost of preparing land for development varies considerably depending on the type of land, the distance from existing networks, and geographical constraints. It is generally estimated that this cost ranges between 6000 and 15,000 euros.
- Maisons SIC systematically includes a thermal study before signing the Construction Contract
The costs of surveying
Sometimes, the desired plot of land is not surveyed, meaning that the property boundaries between two adjacent plots are not marked. Surveying is not mandatory but is strongly recommended before any construction to avoid future neighborhood disputes. In practice, in a diffuse terrainThe cost of boundary surveying is generally borne by the buyer. The cost of a land surveyor varies depending on the land, but it typically ranges between €700 and €1500 including VAT for a standard plot and more 2000 Euros for a complex plot of land (irregular shape, wooded area, several neighbors…
Total price of a new house: the cost of engineering studies
Soil and thermal studies are essential to ensure a comfortable and durable new construction. However, their increasing number impacts the total cost of a new house.
The soil study
When you buy land, a geotechnical study The aforementioned G1 is attached to the preliminary sales agreement in areas moderately and highly exposed to the phenomenon of shrinkage-swelling of claysTo complement this preliminary study, it is strongly recommended to conduct a more comprehensive study. G2 at the stage of building projectThis study allows for precise adjustment of the foundations to the characteristics of the terrain and protects the buildings. The observed cost is generally in the average range of €1,500 to €2,500.
At Maisons Sic We do not overlook this study, which we consider essential to the sustainability of a house.
Learn more by reading our dedicated article " Soil study: stage 1 of a sustainable house in the South-West ».
Thermal study and life cycle analysis
The thermal studyThe study, carried out by a thermal engineering firm, takes into account...orientation of the housethe materials used, their thicknesses, the means of producing heating and hot water, and determines the energy consumption necessary for comfort in the house.
THEbuilding life cycle analysis calculates all greenhouse gas emissions from the materials and the house. These two studies allow us to produce theRE2020 compliance certificate necessary for building permit applicationThey also guarantee that the house complies with regulations and ensures a comfortable level of living with low energy consumption. The cost is generally between between €600 and €1, but it can vary depending on the required precision and complexity.
To go further read the article: “ Building an ecological house: what is a thermal study ».
The RE2020 airtightness test
This test, carried out when the house is watertight and airtight, ensures that the recommendations of the thermal study have been followed. The test thus verifies the absence of air leaks or thermal bridge in order to minimize energy loss. Its cost is 400 to 700 € for a detached house.
To delve deeper and better understand this topic, consult the dedicated article " Soil study: step 1 of a sustainable house in the Southwest »
- The airtightness test is performed at the end of the work The house is ready for handover. This service is included in the Construction Contract.
The development tax
This development taxCalculated from a fixed value defined annually, this tax is payable from… To determine the cost of this tax, multiply the square footage of the house by the value per square meter (this value was set for the year 2025 at…). €930).
Next, we apply the annual rate of the municipal share It can vary from 1% to 5%. It can reach up to 20% in some sectors. Then the annual rate of the departmental share is the same for the entire department. It is fixed at 2,5% maximum.
For example, a house of 50 m², the taxable value will be 930 x 50 = 46,500.
If the municipal rate is 3% and the departmental rate is 2,5%, we obtain:
– €46,500 X 3% = €1,162
– €46,500 X 2,5% = €1,162
This amounts to a development tax of €2,557.
Structural damage insurance
This mandatory insurance secures the house construction. Without waiting for the outcome of a lengthy legal process to receive compensation, thework damage insurance covers the repairs for damages covered by the ten-year guarantee.
It must be taken out before work begins and represents 2 to 3% of the construction cost. At the south west builder Maisons Sicit is included in the house construction contract.
To go further, read the article “ What insurance is available for building with peace of mind in 2024? »
Anticipate the cost of the interior design
At Maisons SicThe client can choose a fully finished house. The builder then has a decorator team who helps her choose her future equipped kitchen and its bathroombut also paints, floor coverings or the built-in cupboardsThe cost varies considerably depending on the services chosen, the size of the house, and the quality of the materials selected. The client is then reassured about the total cost of their move-in ready home.
He can also choose to do the interior finishing and decorating himself, opting for a "ready-to-decorate" house. The cost of this type of work must then be factored in.
An additional cost is generally estimated at 400 to 700 €/m² if you make these yourself interior work and €800 to €1,200/m² with professional craftsmen or service providers.
Anticipate the cost of exterior improvements
Often overlooked in the initial budget, the Outdoor Facilities However, they represent a significant part of the overall cost of a new house, especially when moving into a scattered, still undeveloped plot of land.
This work covers everything that makes your land accessible, functional and pleasant to live in: earthworks, weeding, planting, fencing, gates, hedges, swimming pools, garden paths…
The overall budget to plan for is generally between €8,000 and €20,000 for a basic layout on a plot of 600 to 800 m², but it can reach €30,000 or €50,000 if a terrace, complete fences and landscaping are included.
To go further, read the article “ How much does it cost to design your garden? ».
How to reduce additional costs without unpleasant surprises
Some costs are unavoidable, but others can be reduced. Survey the land before buying to determine the distance to utilities and ensure good site access.
Get quotes for the connections (electricity/water/sewerage) before the construction contract.
Do not neglect the G2 soil study to benefit from optimized foundations.
Anticipate the development tax with the town hall (rate & possible exemptions).
Prioritize your interior renovations. Carefully consider which tasks you can tackle yourself without embarking on a long-term project. Consider entrusting the interior work to your builder for a turnkey project without any unpleasant surprises.
