Building type E: Simply constructed. Safely ventilated.
Stand: April 2026
Building Type E promises more cost-effective construction due to fewer regulations, but even where building codes are relaxed, building physics remain a constant. This guide explains why decentralized ventilation concepts are essential for making Building Type E both safe and marketable, and which specific solutions have proven effective for architects, specialist designers, and installers.
What is Building Type E?
Building Type E stands for “simple construction” and describes an initiative by the Federal Chamber of Architects and the Federal Ministry of Construction that allows for the targeted exemption from non-mandatory DIN standards in new construction. The goal is to achieve a significant reduction in construction costs without compromising legally mandated safety requirements such as structural stability, fire safety, and health protection. Deviations from recognized technical standards are contractually agreed upon between building owners and planners in what is known as a Building Type E contract.
Current Status of Legislation
In November 2025, the Federal Ministry of Justice presented a policy paper on the Building Type E Act, which proposes amendments to the law governing construction contracts (BGB). These amendments are intended to make it easier for architects and building owners to mutually agree to waive certain comfort standards without this automatically giving rise to liability claims. The draft bill is currently going through the parliamentary process. (As of April 2026)
For ventilation design, this means that DIN 1946-6, which governs the ventilation concept for residential units, may be contractually waived for Building Type E. However, this does not affect the physical necessity of adequate air exchange.
Examples and pilot projects
Bavaria is considered a pioneer in simplified construction: Since 2019, the Bavarian Chamber of Architects has supported 19 pilot projects, including residential buildings in Ingolstadt and Munich, in which unnecessary standards were deliberately waived. The results show cost savings of up to 10%, but also confirm that requirements for the building envelope and indoor climate should not be reduced. Other federal states, such as North Rhine-Westphalia and Baden-Württemberg, are considering similar regulations.
You can opt out of standards - but not building physics.
Even though Building Type E allows for deviations from certain DIN standards, the laws of physics apply universally, regardless of contractual agreements. An airtight building envelope—as required by the Building Energy Act (GEG)—prevents natural air exchange. Without controlled ventilation, CO₂ concentrations in apartments rise to levels harmful to health within a few hours, and relative humidity reaches levels that promote mold growth.
DIN 1946-6 provides the calculation method for determining the required air flow rate for each unit of use. Even if this standard is contractually excluded, the physical requirement for a minimum air change rate remains in effect. Designers who forego a ventilation concept bear an increased liability risk—because moisture protection is a statutory protection objective that is non-negotiable even for Building Type E.
Why opening windows alone isn't enough
Window ventilation depends entirely on user behavior: In modern, airtight buildings, residents would need to ventilate thoroughly every two to three hours—even at night and even when they are away. In practice, this does not happen. At the same time, when windows are open in winter, valuable heating energy escapes, noise enters, and moisture protection is not guaranteed. Controlled home ventilation solves these problems independently of user behavior and in an energy-efficient manner.
Advantages and Disadvantages of Building Type E
Building Type E presents both opportunities and risks that architects and specialist designers should carefully weigh. The following overview summarizes the key aspects.
Advantages
By not adhering to non-mandatory standards, construction costs can be reduced by 5 to 10 percent.
Architects have greater creative freedom in terms of material selection, construction methods, and technical design.
Fewer permits speed up the construction process.
Building Type E enables new construction approaches and methods that were previously hindered by rigid standards.
Disadvantages and Risks
When deviating from accepted engineering standards, designers have an increased duty to inform building owners.
Building simply doesn’t mean building poorly: Without thorough planning, structural damage is a risk.
Until the Building Type E Act is finally enacted, there is no clear legal basis.
Failing to comply with ventilation standards significantly increases the risk of mold. The cost of mold remediation ranges from 120 to 170 EUR per square meter — many times the cost of installing a decentralized ventilation system (40 to 70 EUR per square meter). (Source: Joint Appeal by the BDH, FGK, and ZVSHK, 2025)
Decentralized ventilation: Cost-effective protection for Type E buildings
Decentralized home ventilation with heat recovery is the ideal complement to Building Type E: It ensures the air exchange required for building physics without exceeding the budget. Unlike centralized ventilation systems, it does not require complex ductwork or shafts. Installation is carried out via a core drill hole directly in the exterior wall.
|
Criterion |
Window ventilation |
Central CHV |
Decentralized CHV |
|
Installation costs |
low |
high (Pipe installation) |
medium (Core drilling) |
|
Cost per m² |
0 EUR (Investition) |
80–120 EUR/m² |
40–70 EUR/m² |
|
Energy efficiency |
low (Heat loss) |
high (HR > 80 %) |
high (HR > 90 %) |
|
Moisture protection |
user-dependent |
reliable |
reliable |
|
Sound insulation |
low (open window) |
high |
high |
|
Maintenance effort |
keiner |
high (Filter change, Sewer cleaning) |
low (Filter change) |
|
Suitable for new build and renovation |
yes |
new build only |
yes |
|
User independence |
no |
yes |
yes |
Systems such as the LUNOS e²kurz achieve a heat recovery efficiency of over 90% with an installation depth of 200 mm or more, ideal for Building Type E, where design flexibility and cost-efficiency are key priorities.
Protection of the structure
Moisture control is a key consideration for Building Type E: A controlled ventilation system ensures that moisture from the kitchen, bathroom, and living areas is reliably removed. This protects the building envelope from mold growth and contributes to a healthy indoor climate — regardless of occupancy, energy-efficiently, and without compromising comfort.
The trade associations BDH, FGK, and ZVSHK have made it clear in a joint statement:
„This simplification must not result in a lowering of minimum functional, health, and energy standards.“
Verbände-Appell BDH/FGK/ZVSHK zur Raumluftqualität beim Gebäudetyp E (Quelle: si-shk.de)
Easy to install and cost-effective
Decentralized ventilation systems stand out for their ease of installation and minimal setup requirements: a single core drill hole in the exterior wall is all that’s needed, eliminating the need for ductwork and shafts entirely. This not only reduces construction costs but also speeds up the building process. With an investment of 40 to 70 EUR/m², the decentralized solution is significantly cheaper than a central ventilation system and simultaneously protects against follow-up costs from mold remediation (120 to 170 EUR/m²).
Decentralized ventilation units with heat recovery are eligible for subsidies under certain conditions (KfW, BEG). An energy efficiency expert can confirm whether they are suitable for your construction project.
Protection of the structure
Prevents mold and structural damage in buildings.
Easy to install
Easy installation, minimal effort.
Risk-minimized
Low liability risk for architects and building owners.
Cost-effective
Cost-effective to operate, easy to plan.
Preserves value
A durable solution for moisture protection.
Simple solution
No pipe installation, no loss of space due to manholes.
Affordable protection for Building Type E with decentralized ventilation
Easy to build? You bet!
Even if Building Type E relaxes the standards, the physics remain the same: airtight buildings develop mold without air exchange.
Our decentralized ventilation systems serve as a “safety net.” They provide the necessary building protection with minimal planning and cost.
e²short
With heat recovery. Perfect for installation in walls with a minimum thickness of 200 mm.
Smart comfort control
Control system with automatic humidity control: Ensures constant humidity and prevents mold growth.
AB 30/60 Axial exhaust fan
Axial exhaust fan with optimal sound insulation for use in typical exhaust ventilation areas, such as bathrooms, toilets, and kitchens.
FAQ: Frequently Asked Questions About Building Type E and Ventilation
Legally, this waiver is possible if DIN 1946-6 is contractually excluded.
From a technical and liability standpoint, however, a ventilation system is strongly recommended: Without controlled air exchange, the risk of mold growth and poor air quality in modern, airtight buildings increases significantly. Moisture protection remains a statutory requirement even for Building Type E.
No. Window ventilation depends entirely on user behavior and cannot reliably ensure the required minimum air exchange in airtight new buildings. In addition, window ventilation leads to significant energy losses, noise pollution, and inadequate moisture protection, especially during the winter months.
Mold prevention requires continuous air exchange to remove moisture from indoor spaces. Decentralized ventilation systems with heat recovery achieve this automatically and energy-efficiently. The upfront costs (40 to 70 EUR/m²) are negligible compared to the costs of subsequent mold remediation (120 to 170 EUR/m²).
For Building Type E, DIN 1946-6 may be excluded by contractual agreement between the building owner and the designer. However, this does not alter the physical necessity of a ventilation design. The standard provides the calculation method for the minimum air change rate — this requirement applies regardless of any contractual agreement.
Decentralized ventilation systems with heat recovery are particularly well-suited for Building Type E: They offer reliable moisture protection with minimal planning effort, low installation costs, and easy installation via core drilling in the exterior wall. Systems such as the LUNOS e²kurz achieve a heat recovery efficiency of over 90% with an installation depth of 200 mm or more.
Yes. Decentralized systems cost between 40 and 70 EUR per square meter, which is 30 to 50 percent less than the cost of centralized ventilation systems. Since no ductwork or shafts are required, planning and installation costs are significantly reduced. At the same time, heat recovery lowers operating heating costs.
No. Building class E is a category defined by state building codes and refers to buildings with a height of more than 13 meters up to 22 meters. Building type E, on the other hand, describes a construction method with reduced regulatory requirements and has nothing to do with height classification.
The Federal Ministry of Justice’s policy paper has been available since November 2025. The draft bill is currently going through the legislative process. Pilot projects — particularly in Bavaria — are already being implemented. The exact date of nationwide implementation depends on the legislative process. (As of April 2026)
Decentralized ventilation units with heat recovery may be eligible for federal funding under the Federal Program for Efficient Buildings (BEG) under certain conditions. The specific eligibility criteria are tied to efficiency requirements and are subject to change. An energy efficiency expert will confirm whether your specific construction project qualifies.
Service and Planning: Your Safety Net for Building Type E
Thorough planning is key to legal certainty and building protection for Building Type E. LUNOS supports architects, specialist planners, and installers with free, no-obligation consulting — from designing the ventilation concept to selecting products.
Request a non-binding ventilation plan:
📞 +49 30 362 001-91
📧 planung@lunos.de
Monday through Friday during regular business hours
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For more information, please visit our service sections for architects, specialist planners, and installers.