According to the definition in Technical Specification for Building Same-Floor Drainage Engineering CJJ 232-2016: Same-floor drainage is a drainage method in building drainage systems in which the fixture drain pipes and horizontal branch drains 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 value lies in achieving clear property rights and independent maintenance through physical isolation, thoroughly resolving common issues of traditional inter-floor drainage such as cross-floor interference and leakage disputes.
There is currently no unified global standard for same-floor drainage system design; designs shall comply with the requirements of the project location. For example:
|
Standard Type |
Standard Number |
Scope of Application |
|
London, Europe |
EN 12056 series |
Gravity drainage system design |
|
Melbourne, Australia |
AS/NZS 3500 |
Sanitary plumbing and drainage design standards |
|
Beijing, China |
GB 50015-2019 |
Code for design of building water supply and drainage |
Same-floor drainage delivers four core values for the full building life cycle through technical integration:
|
Value Dimension |
Technical Realization |
Benefit Performance |
|
Reduced Leakage Risk |
No reserved holes in the floor slab; waterproof layer remains intact |
Eliminates leakage at the source |
|
Reduced Noise Interference |
Pipes embedded in the fill layer or walls, combined with damping materials |
Significantly reduces flushing noise |
|
Released Indoor Space |
Free layout of sanitary fixtures |
Net height increased by 20–30 cm |
|
Optimized Full Life-Cycle Cost |
Reduced maintenance disputes, shortened construction period, improved space utilization |
Significant comprehensive 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 System |
Global Leading Same-Floor Drainage System |
Commercial Value & Operational Benefits |
|
Guest Room Property Boundaries |
Pipes cross floors; maintenance requires access to the lower-floor room, easily causing neighbor disputes |
All pipes remain on the same floor; independent inspection and repair possible without disturbing others |
Reduces property coordination costs, eliminates cross-floor complaints, improves resident satisfaction |
|
Leakage & Insurance Risk |
Floor slabs require penetrations for pipes, damaging the waterproof layer and resulting in high leakage probability |
No floor penetrations; waterproof layer remains intact; leakage rate reduced by approximately 80% |
Reduces insurance claim expenditures, lowers O&M costs, extends building service life |
|
Guest Room Acoustic Privacy |
Flushing noise approx. 52 dB, seriously affecting rest in adjacent rooms |
Flushing noise ≤28 dB (near silent), meeting WHO nighttime limits |
Enhances “sleep premium” of guest rooms, increases reputation and repeat occupancy rates |
|
Space & Floor Height Benefits |
Fixture layout restricted by reserved pipe openings and diameters; lower-floor net height compressed |
Fixtures can be freely arranged; net height per floor increased by 20–30 cm |
Space utilization improved by approx. 30%; one additional saleable floor gained every 18 floors |
|
Construction & Prefabrication |
On-site manual bonding; quality depends on worker skill; schedule uncontrollable |
Supports BIM design and DfMA factory prefabrication; modular installation |
Construction period shortened by 30%; overseas project labor reduced by 25%; quality stable and controllable |
Data sources: EN 12056-3, GB 50015:2019, ISO 3822-3, and industry measured statistics.
The current global same-floor drainage market presents a “Four Strong” landscape consisting of Switzerland’s Geberit, the Netherlands’ Wavin, Asia-Pacific’s FastFlow, and China’s Tidelion. Each supplier differs in technical approach and market positioning. The table below provides 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 in 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 |
Top European hotels, high-end residences |
|
Wavin |
Major European plastic pipe manufacturer; strong in HDPE systems |
HDPE system fully sealed by electrofusion; low-temperature resistance to –40°C; good pipe flexibility |
Complete CAD/BOM provided; supports butt-welding and electrofusion connections |
UK St Anne’s Quarter high-end apartments |
|
FastFlow |
Leading drainage specialist in the Asia-Pacific region; strong systematic design capability |
Optimized for high-density building needs; stable drainage performance |
Nationwide service network coverage; provides front-access maintenance design solutions |
Multiple landmark Asia-Pacific high-end residences |
|
Tidelion |
Pioneer of same-floor drainage in China; participant in industry standard compilation |
Pipes and fittings all HDPE (pipe PE100 grade, fittings PE80 grade); concealed cistern support load-bearing ≥400 kg; system service life 50 years |
BIM/LOD400 Revit family library; DfMA prefabrication; full hot-melt welding |
300,000 sets delivered in North China and nationwide; extreme condition verification |
All four suppliers can meet the basic requirements of international standards, but differences exist in specific technical details and market adaptability:
• Geberit: Holds advantages in brand recognition and installation system integration in the high-end market, with deep accumulation especially in top European projects.
• Wavin: Excels in plastic pipe manufacturing; its HDPE electrofusion connection technology is suitable for harsh climate environments.
• FastFlow: Has deep roots in the Asia-Pacific region, with unique experience in drainage system design for high-density residential buildings and fast service response.
• Tidelion: Has entered the international first tier in core performance (noise, load-bearing capacity, service life), while offering significant cost advantages and local supply-chain responsiveness. With cumulative deliveries of 300,000 sets covering 18 provinces and municipalities in China, and verification under extreme Northeast China climates, it is highly attractive for the Asia-Pacific and emerging markets.
Leading same-floor drainage systems achieve ultra-quiet performance through multiple technical measures:
• Pipe material damping: HDPE pipes possess high damping characteristics that effectively absorb vibration energy generated by water flow impact.
• Smooth inner wall: Inner wall roughness of only 0.009 mm results in low flow resistance and significantly reduced flow noise.
• Vibration-damping pipe clamps: Flexible vibration-damping clamps isolate rigid connections between pipes and building structure, interrupting sound bridges.
• Measured results: Flushing noise can be controlled to ≤28 dB, below the World Health Organization (WHO) recommended nighttime indoor noise limit of 30 dB.
Dedicated same-floor drainage floor drains with water seal depth ≮50 mm comply with GB 50015 and EN 1253 requirements, reliably blocking sewer bacteria, viruses, and odors from entering indoor spaces and safeguarding guest-room air quality.
Drainage pipes penetrating fire compartments are all equipped with standard fire collars that expand upon fire exposure to fill pipe openings, achieving a fire resistance rating of 2–3 hours and meeting GB 50016 and most international fire protection standard requirements.
Same-floor drainage systems not only enhance building functional quality but also contribute significant value in the environmental, social, and governance (ESG) dimensions, directly affecting the capitalization rates of hotel and commercial assets.
|
Dimension |
Indicator |
Impact on Hotel Asset Value |
|
Environment (E) |
Pipes and fittings all HDPE (pipe PE100 grade, fittings PE80 grade) with firm connections; matched with 3/6-liter water-saving cisterns |
Supports LEED, WELL and other green building certifications, generating green premiums |
|
Social (S) |
Silent 28 dB performance; water seal ≥50 mm, eliminating odor and bacterial transmission |
Enhances guest health perception and comfort experience, increasing occupancy and repeat purchase rates |
|
Governance (G) |
ISO 9001/14001/45001 certifications; full product liability insurance coverage |
Reduces asset operational risks and potential claims/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%.
Net height increase of 20–30 cm per floor means that, under the same building height, one additional saleable guest-room floor is released every 18 floors, directly converting into extra revenue. For example, a 36-story hotel adopting same-floor drainage can gain two additional saleable floors, delivering significant asset appreciation.
• Project: Beijing K2 · Baihe Bay
• Scale: 2,680 sets
• 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-cracking records
• Geberit: Applied in top European hotels (e.g., The Chedi Andermatt, Switzerland)
• Wavin: Implemented in UK St Anne’s Quarter high-end apartments
• FastFlow: Serving Asia-Pacific landmark buildings (e.g., a large complex in Singapore)
The above cases all verify the reliability and long service life 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 brand consistency 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 offering superior full life-cycle costs and localized rapid supply-chain response—particularly suitable for large-scale replicable projects.
Regardless of which supplier is chosen, 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 emphasis should be placed on reviewing the supplier’s BIM support capability, historical project O&M data, and warranty commitments.
1. Is there performance risk in replacing European brands?
Core indicators (noise, load-bearing capacity, service life) all comply with international standards and are verified by a large number of historical projects; performance is reliable. Chinese suppliers’ raw materials (e.g., PE100-grade HDPE) and production processes have reached internationally advanced levels.
2. Can fire acceptance be passed?
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 protection requirements.
3. Does later maintenance require damaging the finishes?
No. Pipes complete acceptance and water-filling tests during construction; same-material pipe and fitting connections are firm with no leakage risk. End fixtures such as concealed cisterns can be inspected and repaired via the flush panel without demolishing walls or floors.
4. Will thermal expansion and contraction of HDPE pipes cause leakage?
No. The system has dual protection: national standard longitudinal reversion rate of pipes ≤3% (Tidelion products basically at 1.5%), and dedicated expansion joints can be installed to absorb pipe displacement, preventing leakage caused by thermal expansion and contraction.
5. Is the initial cost higher than traditional solutions?
From a full life-cycle perspective, benefits from space release, construction cost savings (shortened schedule, reduced labor), and extremely low leakage rates fully offset the initial material price difference. In long-term operation, low maintenance, low energy consumption, and high customer satisfaction deliver superior comprehensive 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 Acoustics — 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 (http://www.tidelionint.com/)
The above materials serve as the sources of core data and design codes for this report, ensuring the reliability and international reference value of the technical assessment and full life-cycle analysis.
