Many restaurants, hotels, and cafeterias in older buildings didn't have elevator shafts reserved during construction. When they want to add a dumbwaiter later, they worry about digging a pit that damages the floor, breaking walls and opening holes that ruin the decor, and construction periods that are too long and disrupt business. GOELEV provides no-pit / shallow-pit solutions, completing installation in 3 days without damaging decor, without digging deep pits, with minimum shaft dimensions of just 850×850mm. This article details the complete retrofit process.
I. Three Core Challenges of Old Building Retrofit
| Challenge | Specific Problem | GOELEV Solution |
|---|---|---|
| No pit | Old building floors have piping underneath / thin slabs, cannot dig standard 300-500mm pit | No-pit solution (0mm) or shallow-pit solution (50-150mm) |
| No shaft space | No reserved shaft, corridor / kitchen area limited | Minimum shaft 850×850mm self-supporting frame |
| Cannot close for business | Restaurant / hotel is operating, cannot have prolonged construction | 3-day fast installation (factory pre-assembly + on-site assembly) |
II. No-Pit Solution vs Shallow-Pit Solution
This is the most critical technical choice for old building retrofit. The two solutions suit different conditions:
| Comparison Item | No-Pit Solution | Shallow-Pit Solution | Standard Pit Solution |
|---|---|---|---|
| Pit depth | 0mm (direct floor installation) | 50-150mm | 300-500mm |
| Floor requirements | Load capacity ≥ 500kg/m² | Load capacity ≥ 300kg/m² | Standard floor slab |
| Applicable floors | ≤ 5 floors (forced-drive) | ≤ 10 floors (traction) | ≤ 15 floors |
| Load capacity limit | 100-200kg | 100-300kg | ≤ 300kg |
| Floor construction | None (direct expansion bolts) | Shallow channeling 50-150mm | Excavation 300-500mm |
| Business closure time | 0 days (night installation) | 0-1 days | 2-3 days |
| Impact on floor below | None | None (does not penetrate slab) | Requires space below |
| Price premium | +0 RMB (standard forced-drive) | +2,000-4,000 RMB | Baseline |
Selection advice: ① 5 floors or below, good floor load capacity → no-pit solution (simplest); ② 6-10 floors, floor can be shallowly channeled → shallow-pit solution (50-150mm, does not penetrate slab); ③ 10 floors or above → standard pit solution (must confirm space below is available).
No-Pit Technical Principle
GOELEV's no-pit solution uses a forced-drive unit (wire rope traction or chain drive), with the machine installed at the top of the shaft and the car and counterweight suspended on wire rope / chain. The floor does not need a buffer pit; the car parks directly at floor level when stopped, pit depth = 0mm.
- Installation method: Drive 4-6 M12 expansion bolts into the floor to fix the shaft frame base
- Floor treatment: Only requires flat floor with adequate load capacity, no excavation needed
- Applicable floors: Concrete floors (≥ 120mm thick), tile floors (can be retained)
- Not applicable: Wood flooring / raised floors (insufficient load capacity, requires reinforcement or switch to shallow-pit)
Shallow-Pit Technical Principle
The shallow-pit solution opens a 50-150mm deep channel in the floor to install buffers and the car parking base. Does not penetrate the floor slab, does not affect the space below, and is the best balance point for 6-10 floor old building retrofit.
- Channel depth: 50-150mm (does not penetrate 120mm standard slab)
- Channel area: Equal to shaft base area (approximately 850×850mm)
- Construction time: About 2-4 hours (including cleanup)
- Restoration method: Pour C30 concrete in channel with pre-embedded base, surface flush with floor
III. Minimized Shaft Solution
Old building retrofit space is typically very tight. GOELEV offers minimized shaft solutions:
| Shaft Solution | External Dimensions | Car Dimensions (clear interior) | Load Capacity | Applicable Scenario |
|---|---|---|---|---|
| Ultra-compact | 750×750mm | 450×450×800mm | 50kg | Food transport only (small restaurants) |
| Compact | 850×850mm | 550×550×900mm | 100kg | Restaurant / hotel (common) |
| Standard | 950×950mm | 650×650×1000mm | 150-200kg | Medium-large restaurants / hotel mixed use |
| Large | 1100×1100mm | 800×800×1200mm | 250-300kg | Cafeteria / hospital meal carts |
850×850mm is the most commonly used "golden size" — occupying only 0.72m², the car can hold 6-8 plates, meeting the needs of 80% of restaurants and small-to-medium hotels.
Shaft Installation Location Selection
| Location | Advantage | Disadvantage | Applicable |
|---|---|---|---|
| Corridor side wall | Doesn't use kitchen space, close to food delivery | Takes 850mm of corridor width | Corridor width ≥ 1.5m |
| Inside service pantry | Concealed, doesn't affect corridor | Takes service pantry space | Service pantry ≥ 3m² |
| Kitchen corner | Convenient food output | Greasy environment, needs enhanced sealing | Sufficient kitchen area |
| Under stairwell | Uses dead space | Height limited, requires custom | Floor height ≥ 2.2m |
| External wall mounted | Doesn't use indoor space | Requires approval, affects exterior | Standalone building / rural |
IV. Power Supply Modification
Old buildings typically only have lighting circuits; a dedicated power supply must be run for the elevator. GOELEV elevator power requirements:
| Model | Voltage | Power | Wire Gauge | Circuit Breaker |
|---|---|---|---|---|
| 50-100kg forced-drive | 220V single-phase | 0.75-1.5kW | 3×2.5mm² | 16A |
| 100-200kg traction | 380V three-phase | 1.5-3.0kW | 3×4.0mm² | 25A |
| 250-300kg traction | 380V three-phase | 2.2-4.0kW | 3×6.0mm² | 32A |
- Power routing: Dedicated circuit from distribution box to elevator control cabinet, not shared with other high-power equipment
- Grounding protection: Must be reliably grounded, ground resistance ≤ 4Ω
- Cable routing: Use cable trays / conduit, no exposed wiring
- Emergency power (optional): UPS or battery backup, car levels to nearest floor and opens doors during power outage
V. Structural Reinforcement
Old building wall load capacity is critical for elevator installation. Different wall types require different reinforcement approaches:
| Wall Type | Load Capacity Assessment | Reinforcement Solution | Price Premium |
|---|---|---|---|
| Reinforced concrete wall (≥ 200mm) | Sufficient (can bear load directly) | No reinforcement needed | 0 RMB |
| Solid brick wall (≥ 240mm) | Average (requires calculation) | Through-wall bolts + steel plate | +1,000-2,000 RMB |
| Hollow brick / AAC block wall | Insufficient (cannot bear load) | Steel frame auxiliary load-bearing (floor-standing) | +3,000-6,000 RMB |
| Lightweight partition / drywall | Completely insufficient | Independent steel frame (no wall load-bearing) | +5,000-8,000 RMB |
VI. Installation Without Damaging Decor
Many old buildings have exquisite decor (hotels, boutique restaurants). Owners are most concerned about the installation process damaging decor. GOELEV's approach:
- Floor protection: 5mm thick PVC protective mat + wood board double coverage in construction area
- Wall protection: PE protective film on both sides of shaft installation position, preventing bolt hole splatter
- Dry construction: Entirely dry-method construction (no large concrete pouring), shallow pit uses minimal self-leveling compound
- No welding (optional): Shaft frame available in bolted assembly structure, no open flame or welding fumes on site
- Finished product transport: Factory pre-assembly + complete unit transport, on-site only assembly and commissioning
- Immediate cleanup: Site cleaned and passage restored at end of each workday
VII. 3-Day Fast Installation Process
| Day | Work Content | Duration | Business Closure Needed |
|---|---|---|---|
| Day 0 | Site survey + solution confirmation + shipping | 1-2 hours | No |
| Day 1 morning | Floor protection + shaft frame assembly and fixation | 3-4 hours | No (partial barriers) |
| Day 1 afternoon | Guide rail installation + machine hoisting + car positioning | 3-4 hours | Yes (half day) |
| Day 2 morning | Door system installation + control cabinet wiring | 3-4 hours | No |
| Day 2 afternoon | Floor call panels + floor displays | 2-3 hours | No |
| Day 3 morning | Empty-load test run + leveling adjustment | 2-3 hours | No |
| Day 3 afternoon | Full-load test run + user training + delivery | 2-3 hours | No |
Actual total installation labor is about 20-24 hours, completed over 3 days. Only Day 1 afternoon requires half-day closure (machine hoisting). Night construction option available — no daytime business closure.
VIII. Inspection Filing and Compliance
Old building dumbwaiter retrofit is classified as special equipment modification and requires an inspection filing process:
- Construction notification: Before installation, submit "Special Equipment Installation Notification" to the local special equipment safety supervision authority
- Installation construction: Licensed installation unit (GOELEV has Class B installation qualification) performs construction per plan
- Supervisory inspection: After installation, schedule supervisory inspection with local Special Equipment Inspection Institute (approximately 1-3 business days)
- Usage registration: Within 30 days after passing inspection, apply for a Usage Registration Certificate; only then can the elevator be put into service
GOELEV provides complete inspection filing document handling service: ① Special Equipment Manufacturing License; ② Type Test Certificate; ③ Installation Notification; ④ Product Quality Certificate; ⑤ Installation Self-Inspection Report; ⑥ Installation Acceptance Report.
IX. Total Retrofit Cost Overview
| Item | Cost Range | Notes |
|---|---|---|
| Elevator complete unit (100kg no-pit forced-drive) | 18,000-25,000 RMB | Includes car, machine, control cabinet, door system |
| Elevator complete unit (200kg shallow-pit traction) | 28,000-38,000 RMB | Includes car, traction machine, control cabinet, door system |
| Shaft frame (aluminum) | 3,000-6,000 RMB | Priced by floor height |
| Shaft frame (stainless steel) | 5,000-9,000 RMB | Recommended (anti-grease corrosion) |
| Structural reinforcement | 0-8,000 RMB | Depends on wall type |
| Power supply modification | 1,000-3,000 RMB | Includes cable + breaker + conduit |
| Inspection filing fees | 2,000-5,000 RMB | Includes inspection institute fee + handling |
| Total (100kg no-pit) | 24,000-38,000 RMB | All-inclusive |
| Total (200kg shallow-pit) | 36,000-55,000 RMB | All-inclusive |
X. Common Retrofit FAQ
Q: What if the old building's load-bearing wall is insufficient?
Choose the independent steel frame solution — the shaft is completely self-supporting, not relying on the wall. The steel frame stands on the floor, and the wall serves only as a screen. Price premium approximately 3,000-8,000 RMB. Suitable for hollow brick walls, lightweight partition walls, drywall, and other non-load-bearing walls.
Q: Can installation proceed without closing for business?
Yes. GOELEV offers a night construction option: construction from 22:00 to 06:00, with normal daytime business. All installation is completed in 3 nights. Only the machine hoisting on the 2nd night requires 1-2 hours of corridor / kitchen access; other procedures can be done with barriers without affecting business.
Q: Will the floor tiles be damaged after retrofit?
The no-pit solution does not touch floor tiles at all (only expansion bolt holes, 14mm diameter, can be filled later). The shallow-pit solution requires cutting tiles within the shaft base area (850×850mm) and channeling 50-150mm. The cut lines are completely hidden inside the shaft and invisible after completion, with no impact on the overall floor appearance.
Q: Isn't 3-day installation too fast?
Not too fast. GOELEV uses factory pre-assembly + finished product transport — the shaft frame, car, and machine are pre-assembled and tested at the factory, with on-site only assembly, fixation, wiring, and commissioning. Actual on-site construction labor is about 20-24 hours, and 3 days is a reasonable schedule. It does not affect quality.
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| Retrofit Dimension | GOELEV Solution |
|---|---|
| Pit | No-pit (0mm) or shallow-pit (50-150mm) |
| Shaft | Minimum 850×850mm, self-supporting frame |
| Power supply | Dedicated circuit 220V/380V |
| Structure | Reinforcement per wall type (0-8,000 RMB) |
| Decor protection | Double coverage + dry construction + no welding |
| Schedule | 3 days (including commissioning and acceptance) |
| Cost | 24,000-55,000 RMB (all-inclusive) |
| Inspection | GOELEV handles all filing |
In short: Old building dumbwaiter retrofit doesn't require digging deep pits, breaking walls, or closing for business. GOELEV's no-pit / shallow-pit solution + minimized shaft + 3-day installation + complete inspection filing makes retrofit as simple as renovation. Factory direct, 3-day shipping, DDP door-to-door with double customs clearance.
About the author: GOELEV (Wuhan Chutian Zhimei Elevator Co., Ltd.), 20 years focused on service elevator / dumbwaiter manufacturing. Factory direct, 3-day shipping, DDP door-to-door with double customs clearance. WhatsApp: +86 18186666598 · [email protected]