Building or having your house built is primarily about translating a lifestyle into square meters. The dream house project rarely starts with the choice of a facade or wall color: it begins with a series of technical decisions that determine the comfort, budget, and durability of the building for decades.
Summer Comfort and RE2020: the criterion your plan must integrate from the start
In the design of a new house today, one parameter weighs more heavily than light, layout, or architectural style: summer comfort is now a regulatory requirement.
The RE2020, in effect since 2022, mandates a calculation of thermal discomfort degree-hours. In simple terms, your house must remain livable during a heatwave without permanent air conditioning. The “Endurance” plan aims to further tighten this indicator in the coming years.
The orientation of living spaces, the size of west-facing windows, the presence of sunshades or roof overhangs, the choice between a floor or a ventilated single story: all of this is decided at the design stage, not after the building permit.
Have you noticed that a room facing directly west becomes stifling from 4 PM in the summer? This is exactly the type of situation that the regulations seek to avoid. An open kitchen with large southwest-facing glazing without solar protection will push the degree-hours beyond the allowed threshold.
To explore different room configurations and layouts adapted to these constraints, the Home Dream house website offers concrete examples that help visualize the possibilities even before contacting a professional.
Building Materials: What the Carbon Reinforcement RE2020 Changes in 2025
Since 2025, submitted individual house projects must comply with a stricter carbon threshold than at the launch of RE2020. This reinforcement directly affects the choice of materials and construction methods.
Traditional concrete, for example, generates a high carbon footprint. Wood, bio-sourced materials, or low-carbon concrete are gaining ground, not as a trend, but because the carbon balance of the construction site is accounted for in the regulatory certificate.
Criteria to Check with Your Builder or Architect
- The carbon weight of structural materials (load-bearing walls, slabs, frameworks) represents the largest part of the project’s total footprint
- Bio-sourced insulation (wood fiber, cellulose wadding) improves summer comfort while reducing the carbon balance, ticking two regulatory boxes at once
- The choice between vapor barriers and vapor retarders influences moisture management in the walls and must be consistent with the chosen construction system
- Performance data for new houses is now available in open data, allowing comparisons with the actual results reported by other projects similar to yours
A high-performance material poorly installed remains an ineffective material. The quality of implementation is as important as the technical data sheet. Ask for examples of completed projects and check the RE2020 certificates obtained.
Plans and Room Layout: Thinking in Life Scenarios
Drawing the plan of a house while only considering the total area is a common trap. A dream house is primarily a layout that corresponds to your actual daily life, not a magazine image.
Take the kitchen. Open to the living room, it enlarges the living space, but it also requires more efficient ventilation and acoustic insulation thought out in advance. Closed, it simplifies the management of odors and noise, but reduces the feeling of space.
Why is this choice so structuring? Because it determines the location of water inlets, ventilation ducts, and the technical column. Modifying this decision after the structural work is much more expensive than making it at the right time.
Three Questions to Decide Before Finalizing Your Plans
Do you work regularly from home? If so, a separate office with a door and lateral natural light radically changes the quality of your days. Placing it on the north or northeast side avoids overheating without sacrificing light.
Do you need a floor? A single story facilitates aging in place and simplifies the structure but requires a larger plot. A partial floor can be a good compromise if the land is constrained.
What relationship do you want between the interior and exterior? A covered terrace extends the living space for several months a year. Properly oriented, it also serves as passive solar protection for the living room.
Budget and Work: Anticipating Items That Quotes Overlook
The budget for a new house is not limited to the construction price. Several items are often underestimated or missing from initial estimates.
- Connection fees to networks (water, electricity, sanitation) vary significantly depending on the location of the land and can represent a significant part of the total budget
- The adaptation of the land (earthworks, soil study, stormwater management) depends on local geology and is not always included in the builder’s quote
- Outdoor developments (fencing, access, landscaping, planting) are often postponed “to later” but end up weighing heavily if the budget has not accounted for a margin
Plan for a margin beyond the signed quote. Adjustments during the construction process are almost systematic: a change of flooring, an additional electrical outlet, an integrated storage solution not planned from the start.
Interior design, finishes, and decoration come last in the schedule, but they must be budgeted from the beginning. Without this, you risk moving into a technically completed house but visually unfinished.
The design of a dream house relies less on inspiration than on technical decisions made at the right time. Orientation, materials, room layout, realistic budget: every decision made before the construction site avoids a compromise imposed later. The RE2020 data available in open data now provides a concrete tool to compare, verify, and adjust your project before signing anything.
