The MEP systems in a restaurant — mechanical, electrical, and plumbing — are what the Saudi Food and Drug Authority (SFDA) and Saudi Civil Defence inspect most carefully before issuing operating licences. Getting the MEP right is not just an engineering question; it is a compliance and programme question. A restaurant that opens on time almost always had its MEP designed correctly from the start. One that stalls at inspection almost always had MEP that was undersized, mis-sequenced, or uncoordinated with kitchen equipment.
This guide covers every MEP discipline for a Riyadh restaurant fit-out in technical detail. For the broader project picture, including authority approvals and timelines, see our complete restaurant fit-out guide.
Why Restaurant MEP Is More Demanding Than Most Commercial Fit-Outs
A restaurant places a higher combined MEP demand on a building than almost any other commercial tenant type. The reasons:
- Heat load. Commercial cooking equipment generates very high heat that must be mechanically extracted — you cannot simply open a window.
- Electrical demand. A mid-scale restaurant kitchen can draw 80–200kW of connected load from cooking equipment alone, before lighting, HVAC, and refrigeration.
- Water and drainage. Commercial kitchens use significant water volumes and produce high-grease wastewater that requires dedicated treatment before entering the main drain.
- Gas. LPG or natural gas supply to cooking equipment must meet Civil Defence requirements for safety interlocks, detection, and shut-off.
- Fire risk. Cooking oil and gas create a specific fire risk that requires dedicated wet chemical suppression systems, separate from the general building sprinkler system.
Dar Anan handles all of these disciplines in-house through our MEP contracting team, which eliminates the coordination failures that occur when multiple subcontractors work on a restaurant MEP scope without unified design responsibility.
Ventilation and Kitchen Extraction
Ventilation is the most technically demanding element of restaurant MEP and the most common cause of SFDA inspection failure. Both the Saudi Building Code (SBC) and SFDA standards set minimum performance requirements.
Extraction Hood Design
The extraction hood must be positioned directly above all cooking equipment and sized to capture the full thermal plume. Key parameters:
- Hood overhang: Minimum 150mm overhang on each side of the equipment footprint, 300mm at the front
- Capture velocity: 0.25–0.35 m/s at the hood face (for a Type I hood above solid-fuel or high-heat equipment)
- Hood height above cooking surface: 600–800mm is typical; higher hoods require proportionally greater airflow to maintain capture
- Grease filters: Stainless steel, baffle type, removable for cleaning — required by both SFDA and Civil Defence
Airflow Calculation
The required extract volume is calculated from the hood face area and the required capture velocity, not estimated. For a typical 5-metre cooking suite:
- Hood face area: approximately 4.5 sqm (5m × 0.9m open face)
- Required capture at 0.3 m/s: approximately 1.35 m³/s or 4,860 m³/hr
- With 20% duct system losses: fan size of approximately 6,000 m³/hr
This is a worked example only. Every installation requires a proper calculation from the actual hood dimensions and equipment layout.
Make-Up Air
Make-up air is the replacement air introduced into the kitchen to compensate for extraction. This is where many designs fail:
- Make-up air must equal minimum 85% of the extraction volume
- Insufficient make-up air creates negative pressure in the kitchen, pulling conditioned air from the dining area through service openings
- Make-up air should ideally be introduced at hood level (short-circuit supply) to improve capture efficiency and reduce the HVAC load on the kitchen
- In Riyadh's climate, make-up air must be cooled in summer months — an unconditioned make-up air system in July will make the kitchen unusable
Ductwork
- Material: galvanised steel, minimum 1.0mm gauge for kitchen exhaust ducts
- Kitchen exhaust ductwork must not share shafts with non-kitchen ventilation systems
- Grease duct must be accessible for cleaning at intervals required by Civil Defence — access panels at maximum 3-metre intervals
- Duct route to atmosphere must not pass through occupied spaces without an approved fire-rated shaft
Dining Area HVAC
The dining area requires a separate HVAC system from the kitchen extraction. In a 200 sqm casual dining restaurant in Riyadh, allow approximately:
- Cooling load: 250–350W per sqm of dining area (higher in west and south exposures)
- Air changes: minimum 6–8 per hour in dining areas per SBC 501
- Fresh air introduction: minimum 10 L/s per person (ASHRAE 62.1 equivalent)
Electrical Systems
Load Calculation
The electrical load in a commercial restaurant kitchen is almost always higher than an inexperienced designer expects. A mid-scale full-service restaurant with a 60 sqm kitchen will typically have a connected electrical load of:
| Equipment Category | Typical Connected Load |
|---|---|
| Combi ovens (2–3 units) | 20 – 45 kW |
| Commercial fryers (2 units) | 16 – 24 kW |
| Commercial grill/plancha | 6 – 12 kW |
| Refrigeration (cold rooms, prep fridges) | 8 – 20 kW |
| Dishwasher (commercial) | 10 – 20 kW |
| Extraction fans and make-up air AHU | 5 – 15 kW |
| HVAC (dining + BOH combined) | 20 – 50 kW |
| Lighting (dining + BOH) | 8 – 20 kW |
| General sockets and miscellaneous | 5 – 15 kW |
| Total connected load | 98 – 221 kW |
Diversity factor reduces the demand load to approximately 60–70% of connected, but the incoming supply and distribution board must be sized for connected load.
Before finalising your restaurant's electrical design, confirm available supply capacity with the Saudi Electricity Company. If the available supply is insufficient, a new supply application adds SAR 40,000–120,000 and 4–8 weeks to the programme.
Distribution and Wiring Standards
All electrical work must comply with the Saudi Building Code electrical requirements and SASO standards for electrical equipment:
- Three-phase supply required for most commercial cooking equipment above 3kW
- Dedicated circuits for all major appliances — no shared circuits for equipment above 2kW
- IP44-rated sockets minimum in all wet areas; IP65 recommended near dishwashing and pot wash
- RCD (earth leakage circuit breaker) protection on all circuits in wet areas
- All cable runs in conduit throughout — no surface-mounted cables in kitchen areas
- Emergency lighting in all areas per Civil Defence requirements
- Adequate socket count for the actual equipment schedule — a common error is designing sockets for the initial equipment only
Lighting
- Kitchen: minimum 500 lux at work surface level (SFDA requirement for food preparation areas)
- Cold rooms: minimum 200 lux
- Dining: specification-dependent, typically 50–200 lux for ambience
- All kitchen lighting to be sealed, non-fragile (or with protective covers) to prevent glass or filament contamination of food
Gas Supply and LPG Safety
Many Riyadh restaurants operate on LPG where a natural gas network connection is not available. Civil Defence requirements for LPG are specific:
LPG Storage
- Cylinders stored externally in a dedicated, ventilated enclosure, not in the kitchen or basement
- Minimum clearance from windows, doors, drains, and electrical equipment as specified in Civil Defence regulations
- Cylinder enclosure to be constructed of non-combustible material, with natural ventilation at high and low level
- Maximum number of cylinders in storage as specified per Civil Defence permit
Gas Pipework
- Certified stainless steel or copper pipework — no flexible connections in concealed locations
- All joints brazed or welded, not mechanical compression fittings in concealed runs
- Pressure regulator at the manifold, sized for total equipment gas load
- Pressure test to 1.5× working pressure before commissioning, documented for Civil Defence
Safety Interlocks
Civil Defence requires:
- Gas solenoid shut-off valve interlocked with the kitchen exhaust fan — if the fan stops, the gas shuts off
- LPG gas detector at low level (LPG is heavier than air) with alarm and automatic solenoid closure
- Manual emergency gas shut-off valve accessible outside the kitchen
Plumbing: Water Supply and Drainage
Water Supply
- Commercial dishwasher requires a dedicated hot water supply at minimum 60°C and 10 L/min flow rate
- A commercial water heater (not domestic) is required — typically a 100–200L commercial unit for a 200 sqm restaurant
- Dedicated cold water supply to each hand wash basin in all food preparation areas — SFDA requires a hand wash basin within 5 metres of any food preparation station
- Water pressure: minimum 2.5 bar at each outlet
The National Water Company (NWC) is the authority for water and drainage connections in Riyadh. Confirm available supply pressure and drainage invert levels with NWC before finalising the drainage design.
Kitchen Drainage
Drainage design in a commercial kitchen is frequently under-specified. Requirements:
- Stainless steel drainage channels under all cooking equipment and in all wet preparation areas
- Floor slope minimum 1:80 (1.25%) to drainage channels — must be verified after the screed is laid before tiles are installed
- Floor drain at every equipment position that produces liquid waste
- Drainage channels sized for the peak waste water flow rate — not a standard domestic size
Grease Traps
A grease trap is mandatory for all food preparation facilities in Riyadh under municipality and NWC requirements. Sizing must be calculated:
- Grease trap capacity is determined by the number of meals served per day and kitchen flow rates, not by kitchen area
- For a 200-seat restaurant with two sittings, a typical grease trap requirement is 1,000–2,000 litres
- Grease trap must be accessible for desludging — typically monthly
- Position the grease trap on the kitchen drainage line before it connects to the main building drain
Fire Suppression
Wet Chemical System
Civil Defence requires a wet chemical fire suppression system above all cooking equipment producing grease-laden vapours. This is a system specifically engineered for cooking oil fires — it is not the same as the general building sprinkler system.
- The wet chemical system must be designed and commissioned by an approved Civil Defence contractor
- Nozzles positioned above each piece of cooking equipment under the hood
- Interlock requirements: The system activation must automatically shut off the gas supply solenoid and de-energise cooking equipment circuits
- The system must be inspected and serviced every 6 months — this is a condition of the Civil Defence certificate
General Building Sprinklers
If the building has a sprinkler system, the restaurant tenancy space must be incorporated into it. The kitchen is typically excluded from the standard sprinkler zone (wet chemical system takes its place) but all other areas — dining, dry storage, staff areas — must be covered.
- Sprinkler head spacing and coverage per NFPA 13 (the standard referenced by Saudi Civil Defence)
- Hydraulic calculation required to verify flow and pressure
Coordinating MEP with Kitchen Equipment
The single most important MEP coordination task is sequencing the MEP design with the kitchen equipment schedule. This cannot be done in sequence — it must be done in parallel:
- Kitchen equipment specialist produces a preliminary equipment schedule with power, gas, water, and drainage requirements for each item
- MEP engineer designs systems based on this schedule — not on assumed loads
- If the equipment schedule changes (it usually does), the MEP design must be updated before fabrication
- Final equipment positions must match the ductwork, drainage, and electrical positions before any slabs are cut or walls are built
Changes to equipment layout after MEP rough-in is complete are expensive and time-consuming. Lock down the equipment schedule before MEP design is finalised.
For a breakdown of the overall project timeline including MEP procurement and installation phases, see our restaurant fit-out timeline guide. For cost benchmarks across all MEP trades, see our restaurant fit-out cost guide.
Dar Anan's electrical and plumbing team and MEP contracting division handle the full scope described in this guide. Contact us to discuss your project requirements.