ADDC / AADC
Abu Dhabi Distribution Company and Al Ain Distribution Company, the electricity and water distribution utilities for Abu Dhabi emirate. They approve connection applications, LV designs and metering arrangements and carry out inspections before energisation, following the emirate's own wiring and water regulations.
Addressable fire alarm
A fire alarm system where each detector, call point and module has a unique address, so the panel shows the exact device in alarm or fault. Standard for most UAE buildings beyond small villas; it must be from a Civil Defence-approved manufacturer and often links to the authority's remote monitoring.
AHU (Air Handling Unit)
A large casing with filters, cooling coil, fan and dampers that conditions and distributes air through ductwork. In the UAE AHUs serve lobbies, malls, halls and hospitals; coil selection must handle high latent load, and casings on roofs need insulation and corrosion protection against heat and coastal air.
Al Sa'fat
Dubai's green building rating system, administered by Dubai Municipality and mandatory for new buildings. It sets minimum requirements on envelope, HVAC efficiency, lighting, water fixtures, metering and commissioning, with higher tiers rewarding further savings. MEP design and submittals must show compliance before permits are issued.
AMC (Annual Maintenance Contract)
A yearly agreement covering PPM visits, reactive call-outs and agreed response times for MEP systems. In the UAE, fire alarm and firefighting systems generally require maintenance by a Civil Defence-approved company. A good AMC defines asset lists, inclusions, spares and reporting clearly.
As-built drawings
Drawings updated to show exactly what was installed, including final routes, valve locations, panel schedules and changes made on site. Authorities and utilities in the UAE commonly require as-builts for completion, and they are essential for future maintenance and fit-out works.
ATS (Automatic Transfer Switch)
A switch that moves essential loads from utility supply to a standby generator when mains power fails, and back when it returns. Life-safety loads such as fire pumps, pressurisation fans, emergency lighting and firefighting lifts are typically fed through ATS-backed essential boards.
BMS (Building Management System)
The central control and monitoring system for HVAC, pumps, lighting, energy meters and alarms, usually with a head-end workstation in the security or facilities room. A useful BMS has a clear points list, trend logging and integration with fire alarm, lifts and district cooling meters.
Booster pump set
A packaged set of duty and standby pumps with variable-speed drives and a pressure vessel that supplies water from the tank to the building at stable pressure. Correct sizing for peak demand, quiet mounting and alternating duty are key; in towers, boosters work with transfer tanks and PRVs.
BOQ (Bill of Quantities)
An itemised list of materials and work with quantities, used for pricing tenders, valuing progress and pricing variations. MEP BOQs break down equipment, pipe and duct runs, cables, fittings and testing. Gaps between the BOQ and drawings are a frequent source of claims, so both are checked together at tender.
Builder's work
Civil and structural works needed to accommodate MEP: openings and sleeves in slabs and walls, equipment plinths, trenches, shaft walls and fire-stopping around penetrations. Builder's work drawings from the MEP contractor must reach the main contractor early, before concrete is poured.
Busduct (busway)
Prefabricated enclosed copper or aluminium busbars used instead of heavy cables for main risers and transformer-to-MDB links. Common in UAE towers because tap-off boxes feed each floor from one riser. Joints need torque checks, and routes must avoid water pipes above.
Cause & effect matrix
A table defining what every fire alarm input triggers: AHU shutdown, damper closure, pressurisation fan start, lift homing, door release, smoke extract and alarm zones. It ties together MEP, lifts and security, and is tested device by device during integrated Civil Defence inspections.
Chiller
A refrigeration machine that produces chilled water, typically around 6–7°C supply, for AHUs and FCUs. Air-cooled chillers sit on roofs and must be derated for UAE ambient and kept clear of dust and recirculating hot air; water-cooled units are more efficient but need cooling towers and treated make-up water.
Cold store
An insulated warehouse or room held at chilled or frozen temperatures for food, pharmaceuticals or logistics. UAE cold stores face extreme heat gain on roofs and docks, so they need well-sealed insulated panels, vapour barriers, floor heating under freezer slabs, high-ambient condensing units and robust alarm monitoring.
CSD (Combined Services Drawing)
A coordination drawing overlaying ducts, pipes, cable trays, sprinklers and structure in ceiling voids and risers, often produced from a BIM model. It fixes levels and crossing points so the false ceiling height is achievable and nothing has to be cut out later on site.
DCD (Dubai Civil Defence)
The authority that approves fire and life safety designs, contractors and products in Dubai, inspects installed systems and issues completion approval before occupancy. Other emirates have their own Civil Defence authorities applying the UAE Fire & Life Safety Code; free zones such as Trakhees areas may route approvals differently.
DDC (Direct Digital Control)
Programmable field controllers that read sensors and drive valves, dampers and VFDs locally, then report to the BMS over protocols such as BACnet or Modbus. DDC panels sit near AHUs and pumps; wiring, labelling and point-to-point checks are a key part of testing and commissioning.
Delta-T (ΔT)
The temperature difference between chilled-water supply and return. A low delta-T means too much water is pumped for the cooling delivered, wasting pump energy and, on district cooling, often triggering penalties. Typical causes are three-way valves, dirty coils, poor balancing and open bypasses.
DEWA
Dubai Electricity and Water Authority supplies power and water in most of Dubai. For building projects it approves load applications and LV designs, substation requirements and water connections, inspects installations and energises supply. Some free zones and master communities have different utility arrangements.
District cooling
Centralised chilled-water plants that serve many buildings through underground pipe networks, widely used in Dubai master communities and parts of Abu Dhabi. The building avoids its own chillers but pays capacity and consumption charges, and its secondary system must return water warm enough to meet the agreed delta-T.
DLP (Defects Liability Period)
The period after handover, commonly twelve months under UAE contracts, during which the contractor must return to fix defects in workmanship or materials. MEP issues often appear in the first summer, such as condensation, undersized drains or tripping circuits, so a full cooling season within the DLP is valuable.
Earthing
The system of earth electrodes, conductors and bonding that keeps exposed metalwork at safe potential and lets protective devices trip on faults. In UAE sandy soils, achieving low resistance can need deeper rods or soil treatment; pits are tested and recorded for utility inspection.
ELV (Extra Low Voltage)
Low-voltage signal systems: structured cabling, CCTV, access control, intercom, public address, IPTV and often fire alarm. In Dubai, CCTV in many building types must meet SIRA requirements. ELV needs separate containment from power cables and coordinated riser space.
Estidama Pearl Rating
Abu Dhabi's sustainability framework administered by the Department of Municipalities and Transport. New buildings must achieve at least 1 Pearl and government-funded buildings at least 2 Pearls, affecting HVAC efficiency, water use, metering, refrigerants and commissioning evidence across design and construction.
Etihad WE
Etihad Water and Electricity, formerly FEWA, supplies power and water in the northern emirates such as Ajman, Umm Al Quwain, Ras Al Khaimah and Fujairah, with some local variations. Contractors submit load and connection applications and arrange inspections with Etihad WE before handover.
ETS (Energy Transfer Station)
The plant room where a building connects to a district cooling network, usually through plate heat exchangers, control valves and energy meters. The provider owns the primary side; the MEP contractor builds the secondary side and must meet the provider's design, testing and handover requirements.
FAHU / TFA (Fresh Air Handling Unit)
A unit that takes 100% outdoor air, pre-cools and dehumidifies it, often through a heat-recovery wheel or plate using exhaust air, then supplies it to FCUs or rooms. In humid UAE summers a properly sized FAHU is what prevents condensation, mould and sticky indoor air.
FCU (Fan Coil Unit)
A small terminal unit with a fan and chilled-water coil serving a single room or zone, usually concealed above a false ceiling in apartments, hotel rooms and offices. Good practice includes accessible filters, a sloped drain pan with a proper trap, and a two-way control valve.
Fire pump / jockey pump
The fire pump set typically includes an electric main pump, a diesel standby pump and a small jockey pump that maintains system pressure and covers minor leaks so the main pumps do not short-cycle. Sets must be listed, start automatically on pressure drop and be flow-tested in front of Civil Defence.
G+X notation
The UAE shorthand for building height: G is ground floor and X the number of upper floors, with additions such as B for basements, P for podium levels, M for mezzanine and R for roof, for example 2B+G+4P+30+R. It quickly signals riser lengths, pressure zoning, typical-floor repetition and plant locations.
Grease trap (grease interceptor)
A chamber that separates fats, oils and grease from kitchen wastewater before it reaches the public sewer. UAE municipalities require them for restaurants, hotels and labour camp kitchens, with sizing per their guidelines, accessible covers and a documented emptying schedule by licensed waste contractors.
HVAC
Heating, Ventilation and Air Conditioning. In the UAE it is almost entirely a cooling and dehumidification problem: equipment is selected for roughly 46–50°C ambient, fresh air must be dried before entering occupied space, and ventilation rates are typically designed to ASHRAE 62.1.
Inspection chamber / manhole
An access chamber on underground drainage at changes of direction, junctions and set intervals, allowing rodding and inspection. In the UAE chambers are typically precast or GRP with sealed covers rated for traffic loads, and lines are tested and CCTV-surveyed before municipality connection approval.
ITP (Inspection and Test Plan)
A schedule listing every inspection and test for a work package, the acceptance criteria, records required and hold or witness points for the consultant. For MEP it covers items such as material receiving, pressure tests, insulation, megger tests and commissioning, forming the backbone of quality records.
Kitchen grease duct
The exhaust duct from commercial kitchen hoods, built from welded or sealed heavier-gauge steel, fire-rated where it passes through the building, with access doors for cleaning and graded runs to avoid grease pooling. Hood suppression systems and periodic professional cleaning are typical requirements in UAE restaurants and hotels.
Legionella control
Managing the bacteria that grow in warm stagnant water and spread through aerosols from showers and cooling towers. In the UAE, roof tanks and pipes often run warm, so designs avoid dead legs, insulate cold water, keep hot water hot, and O&M includes tank cleaning, disinfection and sampling, with municipal requirements on cooling towers.
LV (Low Voltage)
The building's 400/230 V distribution downstream of the utility transformer, covering switchboards, cabling, final circuits and earthing. In the UAE, LV design and installation follow the regulations of the relevant utility such as DEWA, SEWA, ADDC/AADC or Etihad WE, which inspect before energisation.
Main contractor
The company holding the main construction contract with the employer, responsible for overall programme, site safety, coordination and usually civil and structural works. MEP may be self-performed or subcontracted; the main contractor manages interfaces such as builder's work, access, hoisting and authority inspections.
MDB / SMDB / DB
The LV hierarchy: the Main Distribution Board receives supply from the transformer, Sub-Main Distribution Boards feed floors or plant, and final Distribution Boards serve lighting and power circuits. Panel schedules, discrimination studies and load calculations are submitted to the utility for approval.
MEP
Mechanical, Electrical and Plumbing: the building services package covering HVAC, power and lighting, water supply, drainage and usually fire protection. In UAE projects MEP often represents a large share of contract value and drives authority approvals with Civil Defence, the utility and the municipality.
Method statement
A document describing step by step how a specific activity will be carried out, with resources, sequence, quality checks and the linked risk assessment. Examples include chiller lifting, riser pipe installation or busduct erection. Consultants approve it before work starts, and site teams are briefed on it.
NOC (No Objection Certificate)
A formal clearance from an authority, utility or master developer allowing works to proceed, such as a power or water connection, Civil Defence design approval, road cutting or a community developer's fit-out NOC. Missing NOCs are a common cause of delayed handover, so they are tracked from design stage.
Nominated subcontractor
A specialist, often the MEP contractor, selected by the employer or consultant but contracted through the main contractor. Common on larger UAE projects. Payment flows through the main contractor, so the subcontract terms on programme, retention and coordination responsibilities need careful review.
O&M manual
The handover document set describing how to operate and maintain each system: equipment data sheets, approved submittals, spare parts lists, maintenance schedules, warranties, test certificates and supplier contacts. Facility managers rely on it during the defects liability period and beyond.
Plant room
A dedicated space for major MEP equipment such as pumps, tanks, chillers, ETS, LV panels, generators or AHUs. Good plant rooms are sized for maintenance clearances and equipment replacement routes, are ventilated or cooled, have floor drainage and bunding, and keep water services away from electrical panels.
Podium
The lower, wider block of a tower, usually car parking, retail or amenities beneath the residential or office floors. Podium car parks drive jet-fan smoke extract, ventilation and sprinkler design, and the podium roof often hosts pools, landscaping and MEP plant that need waterproofing-aware penetrations.
PPM (Planned Preventive Maintenance)
Scheduled maintenance tasks at set frequencies: filter changes, coil cleaning, belt and bearing checks, panel thermography, pump and fire system tests. In UAE conditions dust loading makes filter and condenser cleaning far more frequent than in temperate climates, and PPM records support warranty and Civil Defence obligations.
Pre-action system
A sprinkler system whose pipes stay dry until a detection system confirms fire and opens the control valve, so water only discharges if a head also operates. Used where accidental water damage is costly, such as data rooms, archives and some cold stores.
Provisional sum
An allowance in the contract for work that cannot be fully defined at tender, such as utility connection charges, specialist systems or authority fees. It is adjusted to the actual cost once instructed, so clients should treat it as an estimate, not a fixed price.
PRV (Pressure Reducing Valve)
A valve that lowers downstream water pressure to a set value. In high-rise water and fire systems PRV stations divide the building into pressure zones so lower floors are not over-pressurised; they are installed in pairs for maintenance and must be checked periodically because failure causes leaks and burst fittings.
Retention
A percentage withheld from each interim payment as security for completion and defects, typically half released at handover and the balance after the defects liability period. The percentage and release conditions are set in the contract; subcontract retention terms usually mirror the main contract.
RFI (Request for Information)
A formal query from the contractor to the consultant when drawings or specifications are unclear, conflicting or incomplete, for example a clash between a duct and a beam. RFIs create a dated record; answers that change scope may lead to a variation, so they are tracked in a log.
Riser (service shaft)
A vertical shaft carrying pipes, ducts, busducts or cables between floors. Riser sizing is fixed early and is hard to enlarge later. Separate electrical, ELV and wet risers, fire-rated walls and doors, fire-stopping at each slab and access for maintenance are standard requirements.
SEWA
Sharjah Electricity, Water and Gas Authority, the utility for Sharjah. MEP contractors deal with SEWA for load approvals, electrical and water connection drawings, inspections and meter installation. Its requirements and submission formats differ from DEWA, so Dubai templates cannot simply be reused.
Shop drawing
Detailed installation drawings prepared by the contractor from the consultant's design, showing actual equipment sizes, duct and pipe routes, levels, supports and access. They must be approved by the consultant before installation and are where clashes with structure and other trades are resolved.
Smoke extract (smoke management)
Mechanical systems that remove smoke from car parks, atria, malls and corridors so occupants can escape and firefighters can see. Fans and ducts must be rated for high-temperature operation, powered from essential supply, and triggered by the fire alarm per the cause and effect matrix. Car parks often use jet fans.
Snag list (punch list)
A list of incomplete or defective items recorded during inspections before handover, such as missing labels, damaged insulation, loose grilles or untested circuits. Each item is assigned, closed out with evidence and re-inspected; open snags usually hold back completion certificates or retention release.
Soil & waste
Soil pipes carry WC and urinal discharge; waste pipes carry basins, showers, sinks and floor drains. UAE practice often keeps them separate inside the building, sometimes with greywater reuse, and uses uPVC or HDPE with correct gradients, cleanouts and acoustic wrapping in residential shafts.
Sprinkler system
Automatic water-based fire suppression with heat-sensitive heads that open individually over a fire. Wet-pipe systems are most common; hazard classification, head spacing and hydraulic calculations follow the UAE Fire & Life Safety Code with NFPA references, and installers must be Civil Defence-approved.
Stair pressurisation
Fans that push outdoor air into protected stairs and lobbies during a fire, keeping them at higher pressure so smoke cannot enter while doors remain openable. Design covers fan sizing, relief, intake location away from smoke, and acceptance tests of pressure differentials and door-opening force.
T&C (Testing and Commissioning)
The staged process of proving installed systems work: pressure tests, megger tests, flushing, pre-commissioning checklists, start-up, functional and integrated tests such as fire-mode cause and effect. In the UAE, Civil Defence and utility inspections depend on completed, witnessed T&C records.
TAB (Testing, Adjusting and Balancing)
Measuring and adjusting air and water flows so every diffuser, coil and branch receives its design quantity. Done after systems are clean and running, usually by a specialist, and recorded in TAB reports that consultants and authorities may review before handover.
Trakhees
The regulatory arm of Ports, Customs and Free Zone Corporation, acting as building and civil defence authority for areas such as Jebel Ali Free Zone and several Nakheel and Dubai World communities. Projects there submit MEP and fire designs to Trakhees rather than Dubai Municipality.
Transfer tank
An intermediate water tank on a mid-level plant floor of a tall building, filled by transfer pumps from the lower tank and feeding the zones above. It breaks static pressure into manageable stages. Like all stored water in UAE heat, it needs insulation, sealed access and regular cleaning to control Legionella.
UPS (Uninterruptible Power Supply)
Battery-backed equipment that keeps critical loads such as servers, BMS, security and medical equipment running without interruption, bridging the gap until a generator starts. UPS rooms in the UAE need dedicated cooling, since battery life drops sharply at high temperature.
Variation order (VO)
A formal instruction changing the scope, specification or sequence of contracted work, with agreed cost and time effects. In MEP, VOs often arise from late design changes, tenant fit-out requirements or authority comments. Work should be instructed in writing before it is executed to avoid disputes.
VAV (Variable Air Volume)
An all-air system where each zone has a VAV box that throttles supply airflow to meet its thermostat, while the AHU fan slows down on a variable-speed drive. Common in Grade A offices; it saves fan energy but needs careful minimum-airflow settings to keep fresh air and humidity control.
Vent stack
A vertical pipe that admits air into the drainage system so water seals in traps are not siphoned and sewer gases escape above roof level. In towers, relief vents and cross-venting prevent pressure surges; poor venting shows up as gurgling fittings and smells in apartments.
VRF / VRV
A direct-expansion system where one outdoor condensing unit feeds refrigerant to many indoor units with individual control. Popular in UAE villas, low-rise offices and retrofits without chilled water. Key points are high-ambient rated outdoor units, correct refrigerant pipe lengths, leak testing and brazing under nitrogen.