As defined in the Technical Specification for Same-Floor Drainage Engineering in Buildings CJJ 232-2016: Same-floor drainage is a drainage method in building drainage systems in which the fixture drain pipes and horizontal branch drain pipes do not penetrate the structural floor slab of the current floor into the space below, and are laid on the same floor as the sanitary fixtures and connected to the drainage stack. Its core lies in achieving clear property rights and independent maintenance through physical isolation, thoroughly resolving common problems of traditional inter-floor drainage such as cross-floor interference and leakage disputes.
Currently, there is no globally unified standard for same-floor drainage system design; design requirements are based on the project location. Examples include:
|
Standard Type |
Standard Number |
Scope of Application |
|
Europe (London) |
EN 12056 Series |
Gravity Drainage System Design |
|
Australia (Melbourne) |
AS/NZS 3500 |
Sanitary Plumbing and Drainage Design Standard |
|
China (Beijing) |
GB 50015-2019 |
Code for Design of Building Water Supply and Drainage |
Through technical integration, same-floor drainage delivers four core values across the full building lifecycle:
|
Value Dimension |
Technical Implementation |
Benefit Performance |
|
Reduced Leakage Risk |
No reserved openings in floor slab; complete waterproofing layer |
Eliminates water leakage at the source |
|
Reduced Noise Interference |
Pipes embedded in fill layer or walls, combined with damping materials |
Significantly reduces flushing noise |
|
Indoor Space Liberation |
Fixtures can be freely arranged |
Clear height increase of 20–30 cm |
|
Optimized Full Lifecycle Cost |
Fewer maintenance disputes, shorter construction period, improved space utilization |
Significant overall benefits |
The following table compares traditional inter-floor drainage with global leading same-floor drainage systems across key dimensions, highlighting the latter’s superiority in commercial operations and property management.
|
Evaluation Dimension |
Traditional Inter-Floor Drainage |
Global Leading Same-Floor Drainage |
Commercial Value & O&M Benefits |
|
Guestroom Property Boundaries |
Pipes cross floors; repairs require entry into lower-floor rooms, easily causing neighbor disputes |
All pipes remain on the same floor; independent inspection without disturbing others |
Lower property coordination costs; eliminates cross-floor complaints; improves resident satisfaction |
|
Leakage & Insurance Risk |
Floor slab must be perforated for pipe installation; ground waterproofing layer is damaged; high leakage probability |
No floor slab perforations; complete waterproofing layer; leakage rate reduced by approximately 80% |
Reduced insurance claim expenditures; lower O&M costs; extended building lifespan |
|
Guestroom Acoustic Privacy |
Flushing noise approx. 52 dB; seriously affects rest in adjacent rooms |
Flushing noise ≤28 dB (near silent); meets WHO nighttime limit |
Enhances guestroom “sleep premium”; increases reputation and return stay rates |
|
Spatial Floor Height Benefits |
Fixture layout constrained by drain pipe reserved openings and diameters; lower-floor clear height compressed |
Fixtures freely arrangeable; clear height per floor increases by 20–30 cm |
Space utilization improves by approx. 30%; every 18 floors yields 1 additional saleable floor |
|
Construction & Prefabrication |
On-site manual bonding; quality depends on worker craftsmanship; schedule uncontrollable |
Supports BIM design and DfMA factory prefabrication; modular installation |
Construction period shortened by 30%; overseas project labor reduced by 25%; stable and controllable quality |
Data sources: EN 12056-3, GB 50015:2019, ISO 3822-3, and industry field measurement statistics.
The global same-floor drainage market currently presents a “four-power” landscape comprising Switzerland’s Geberit, the Netherlands’ Wavin, Asia-Pacific’s FastFlow, and China’s Taining (Tidelion). Each supplier differs in technical approach and market positioning. The table below provides a benchmarking analysis based on publicly available technical parameters and engineering practice.
|
Supplier |
Technical Positioning |
Core Parameters |
Engineering Adaptability |
Representative Projects |
|
Geberit |
Global high-end leader; leading cistern and installation system technology |
Flushing noise approx. 28–35 dB; zero-drop side-wall floor drain thickness only 3.5 cm; load-bearing ≥400 kg |
Comprehensive BIM library support; mature modular installation system |
European top-tier hotels, high-end residences |
|
Wavin |
Major European plastic pipe manufacturer; strong in HDPE systems |
HDPE system with electrofusion full sealing; low-temperature resistance −40°C; excellent pipe flexibility |
Provides complete CAD/BOM; supports butt welding and electrofusion connections |
UK St Anne’s Quarter high-end apartments |
|
FastFlow |
Asia-Pacific regional leading drainage specialist; strong systematic design capability |
Optimized for high-density building requirements; stable drainage performance |
Nationwide service network coverage; provides front-access inspection design solutions |
Multiple landmark Asia-Pacific high-end residences |
|
Taining (Tidelion) |
Domestic pioneer of same-floor drainage; co-author of industry standards |
Pipes and fittings all HDPE (pipes PE100 grade, fittings PE80 grade); concealed cistern bracket load-bearing ≥400 kg; system service life 50 years |
BIM/LOD400 Revit family library; DfMA prefabrication; full hot-melt welding |
North China and 300,000 units delivered; extreme condition validation |
All four suppliers can meet the basic requirements of international standards, but differences exist in specific technical details and market adaptability:
• Geberit has advantages in brand recognition and installation system integration in the high-end market, with deep accumulation especially in European top-tier projects.
• Wavin excels in plastic pipe manufacturing; its HDPE system electrofusion connection technology is suitable for harsh climatic environments.
• FastFlow has deep roots in the Asia-Pacific region, with unique experience in drainage system design for high-density residences and fast service response.
• Taining (Tidelion) has entered the international first tier in core performance (noise, load-bearing capacity, service life), while possessing significant cost advantages and local supply chain responsiveness. With cumulative deliveries of 300,000 units covering 18 provinces and municipalities in China—particularly validated under extreme Northeast China climates—it is highly attractive for Asia-Pacific and emerging markets.
Leading same-floor drainage systems achieve ultra-quiet performance through multiple technical measures:
• Pipe material damping: HDPE pipe material has high damping characteristics and can effectively absorb vibration energy generated by water flow impact.
• Smooth inner wall: Inner wall roughness is only 0.009 mm; low flow resistance significantly reduces flow noise.
• Vibration-damping pipe clamps: Flexible vibration-damping pipe clamps isolate rigid connections between pipes and building structure, blocking sound bridge transmission.
• Measured results: Flushing noise can be controlled at ≤28 dB, below the World Health Organization (WHO) recommended nighttime indoor noise limit of 30 dB.
Same-floor drainage dedicated floor drains have water seal depth ≥50 mm, complying with GB 50015 and EN 1253 requirements, reliably blocking sewer bacteria, viruses, and odors from entering indoor spaces and safeguarding guestroom air quality.
Drainage pipes penetrating fire compartments are all equipped with standard fire collars. In the event of fire, they expand to fill pipe openings, achieving a fire resistance rating of 2–3 hours, meeting GB 50016 and most international fire safety standard requirements.
Same-floor drainage systems not only enhance building functional quality but also contribute significant value across environmental, social, and governance (ESG) dimensions, directly affecting the capitalization rate of hotel and commercial assets.
|
Dimension |
Indicator |
Impact on Hotel Asset Value |
|
Environment (E) |
Pipes and fittings are all HDPE material (pipes PE100 grade, fittings PE80 grade) with secure connections. Paired with 3/6-liter water-saving cisterns |
Supports LEED, WELL and other green building certifications; generates green premium |
|
Social (S) |
Silent 28 dB; water seal ≥50 mm; eliminates odor and bacterial transmission |
Enhances guest sense of health and comfort; increases occupancy and repurchase rates |
|
Governance (G) |
ISO 9001/14001/45001 certified; full product liability insurance coverage |
Reduces asset operational risk; decreases potential claims and legal disputes |
Leading suppliers all provide comprehensive BIM family libraries. Combined with DfMA prefabricated design, construction cycles can be shortened by 30% and labor costs reduced by 25%.
Clear height per floor increases by 20–30 cm, equivalent to releasing one floor of saleable guestroom space for every 18 floors under the same building height, directly converting into additional revenue. For example, a 36-story hotel adopting same-floor drainage can gain 2 additional floors of saleable area, with significant asset appreciation.
• Project: Beijing K2 · Lily Bay
• Scale: 2,680 units
• Operating time: 16 years
• Maintenance rate: only 0.5%
• Measured noise: ≤28 dB
• Project: Harbin Chenneng Xishu Courtyard
• Conditions: −35°C extreme cold weather
• Performance: No freeze-crack records
• Geberit: Applied in European top-tier hotels (e.g., The Chedi Andermatt, Switzerland)
• Wavin: Deployed at UK St Anne’s Quarter high-end apartments
• FastFlow: Serving Asia-Pacific landmark buildings (e.g., a major mixed-use complex in Singapore)
The above cases validate the reliability and long-life characteristics of same-floor drainage systems under different climates and building types.
Based on technical comparison and market analysis, the following procurement strategies are proposed for different project positioning:
European brands (such as Geberit) may continue to be adopted to maintain consistency of brand positioning and technical accumulation endorsement, especially suitable for scenarios pursuing ultimate installation details and design flexibility.
It is recommended to select Chinese suppliers whose performance has reached the international first tier with clear cost advantages. They make no compromise on core indicators such as silence, load-bearing capacity, and service life, while providing superior full lifecycle costs and localized rapid supply chain response—especially suitable for large-scale replication projects.
Regardless of which supplier is selected, it is recommended to combine BIM design with DfMA prefabrication solutions to maximize construction period reduction, minimize on-site wet work, and enhance asset returns. During the tendering stage, key scrutiny should be given to the supplier’s BIM support capability, historical project O&M data, and warranty commitments.
Core indicators (noise, load-bearing capacity, service life) all comply with international standards and are validated by a large number of historical projects; performance is reliable. Chinese suppliers’ raw materials (such as PE100-grade HDPE) and production processes have reached internationally advanced levels.
Yes. All pipes penetrating fire compartments are equipped with standard fire collars, achieving a fire resistance rating of 2–3 hours, fully complying with GB 50016 and international fire safety requirements.
No. Pipes have already completed acceptance and water-filling tests during construction; pipes and fittings of the same material are securely connected with no leakage risk. Terminal fixtures such as concealed cisterns can be inspected and maintained via the flush panel without removing wall or floor finishes.
No. The system has dual safeguards: national standard longitudinal shrinkage rate of pipe materials ≤3% (Taining products typically around 1.5%), and dedicated expansion joints can be installed to absorb pipe displacement, preventing leakage caused by thermal expansion and contraction.
From a full lifecycle perspective, the benefits from space liberation, savings in construction costs (shorter periods, reduced labor), and extremely low leakage rates fully cover the initial material price difference. In long-term operations, low maintenance, low energy consumption, and high customer satisfaction deliver superior overall economic benefits.
1. GB 50015-2019 Code for Design of Building Water Supply and Drainage — Ministry of Housing and Urban-Rural Development of China
2. EN 12056-3:2000 Gravity Drainage Systems Inside Buildings — European Committee for Standardization (CEN)
3. ISO 3822-3:2018 Laboratory Tests on Noise Emission from Appliances and Equipment Used in Water Supply Installations — International Organization for Standardization (ISO)
4. GIR Global Market Report, 2025–2030: Plumbing and Drainage Systems — Global Industry Research
5. LEED v4.1 and WELL v2 Certification Guides — U.S. Green Building Council (USGBC)
6. Supplier technical white papers and project O&M reports — Geberit, Wavin, FastFlow, Tidelion
