Mechanical Services In MEP Construction



Particular Specification For Mechanical Services describes various general requirements In MEP Construction Work, a contractor to follow when they start executing but not limited to unforeseen work or requirements to accomplish the whole project contract.



Main Highlights in This MEP Specification

  1. Standards
  2. Design and Standardisation
  3. Manufacturers Standards
  4. Galvanising
  5. Labels and Number Plates
  6. Fixings
  7. Builders Work
  8. External Support Brackets
  9. Cleaning and Painting
  10. Oil and Gas
  11. Fire Precautions
  12. Radio Interference
  13. Padlocks
  14. Tools
  15. Expansion Joints
  16. Equipment Documentation
  17. Contract Drawings
  18. Drawings Prepared by the Contractor for Construction
  19. Record Documents and Drawings
  20. Familiarisation
  21. Protection of Unfinished Work
  22. Acceptance of Equipment and Material
  23. Programme of Work
  24. Liaison with Other Parties


Except where modified by this Specification, equipment and materials shall be in accordance with IEC (International Electrotechnical Commission), ISO (International Organisation for Standardisation) and BSS (British Standards Specification) recommendations. If relevant IEC, ISO and BSS recommendations are not available then relevant national standards shall apply, and such national standards shall be proposed by the Contractor for acceptance by the Engineer. When IEC or ISO or BSS recommendations, or national standards are referred to the Edition shall be that current at the date of Tender, together with any amendments issued to that date.

If requested by the Engineer, the Contractor shall supply at his own expense three copies in English and one in the original language of any national standards which are applicable to the Contract.

The whole of the electrical installation shall comply with the requirements of the current edition of the Regulations for Electrical Installations issued by the I.E.E. (Institution of Electrical Engineers), London, UK including the latest amendments thereto.

Design and Standardisation

The Contract Works shall be installed to facilitate inspection, cleaning and repairs, and for operation in which continuity of service is the first consideration. All material and apparatus shall be of the best quality, designed to ensure satisfactory operation under the atmospheric conditions prevailing at the Site and under such sudden variations of load and voltage as may be met with under working conditions.

The installation shall incorporate every reasonable precaution and provision for the safety of all those concerned in the operation and maintenance of the Contract Works and of associated works supplied under other Contracts.

All apparatus shall operate without undue vibration and with the least practicable amount of noise. Operating boxes, kiosks, cubicles and similar enclosed compartments forming part of auxiliary  equipment shall be adequately ventilated to restrict condensation and, where environmental conditions require, suitable integral low-temperature heaters shall be provided. All contractor or relay coils and other parts shall be suitably protected against corrosion.

All outdoor apparatus shall be so designed as to avoid pockets in which water can collect.

Accessible means shall be provided for the easy lubrication of all bearings, mechanisms and moving parts. Grease lubricators shall be fitted with hexagon nipples.

All mechanisms shall, when necessary, be constructed of stainless steel, brass or gunmetal to prevent sticking due to rust or corrosion.

All connections and contacts shall be of ample section and surface for carrying continuously the specified currents without undue heating, and shall be secured by bolts or set screws of ample size, fitted with locking devices of accepted type and material.

All apparatus shall be designed to obviate the risk of accidental short circuit due to animals, birds and vermin. Openings in ventilated enclosures shall be so constructed to prevent the entry of vermin and insects.

All apparatus incorporating doors shall be erected so that the doors can be opened to at least 90o after adjacent equipment has been installed.

Manufacturers Standards

Except where specified otherwise, all materials and equipment associated with the installation shall be handled and installed strictly in accordance with the manufacturers' recommendations by workmen who have had previous experience of the equipment and materials and who have, where necessary, attended a manufacturers course on use and installation.

The Contractor shall ensure that any special tools recommended by manufacturers for the installation of their materials and equipment are used by the workmen.


Galvanising shall be applied by the hot dipped process. The preparation for galvanising and the galvanising process shall not adversely affect the mechanical properties of the material being coated.

Pre-site drilling, punching, cutting, bending and removal of burrs shall be completed before galvanising. Surfaces in contact with oil shall neither be galvanised nor cadmium plated, unless finished with an oil resisting varnish.

The average thickness of the zinc coating shall be equivalent to not less than 0.6 kg/m2 of zinc for all surfaces, except steel wires. The thickness of the zinc coating for steel wires shall be in accordance with a national standard and shall be accepted by the Engineer.

Labels and Number Plates

All equipment shall be clearly and permanently labelled, to the acceptance of the Engineer, in English. Where labels are provided for making clear the method of operation of apparatus, they shall be concise and preferably diagrammatic in form. Duplicate labels in the national language shall be provided whenever applicable.

Labels shall be of the engraved traffolite type.

Labels for similar equipment shall be of uniform appearance and size, and all labels shall be fixed by screws.

Each item of equipment shall be marked with its function, manufacturer's name or trade mark and the code or type number, together with the batch or serial number.

Danger notices shall have red lettering on a white background. All other labels and number plates shall have black lettering on a white background. Generally lettering for danger notices shall be 10 mm high and all other lettering 6 mm high.

All outdoor switchgear shall be clearly and permanently identified by number plates and phase discs of appropriate colours. The rating and circuit identification of each fuse shall be marked adjacent to the fuse base.

The Contractor shall submit a schedule of labels for acceptance by the Engineer before engraving is carried out.


Fixings to brickwork and blockwork shall be made in the bricks and blocks and not in the bond. Wood screws shall be zinc coated and machine thread screws shall be solid brass and greased before installation. Accessories mounted in fixed equipment shall incorporate adjustable slotted fixing holes.

Heavy equipment shall be fixed with accepted purpose-made clamp brackets, ragbolts or patent fixing bolts. Shot plugs or bolts shall not be used without the written acceptance of the Engineer.

No structural steelwork shall be drilled for any purpose without the written acceptance of the Engineer. In general all fixings to steelwork shall be by means of studs welded to the steelwork or by clamp-brackets or hook bolts. Exterior steelwork fixings shall be galvanised.

The supply and fixing of all supports, brackets, clamps and spacers and any other steelwork, whether or not shown in detail on the drawings required for the proper and effective fixing of any equipment, shall be considered to be included in the material and labour covered by the supply and fixing of that equipment. Bolts and studs for electrical connections shall preferably be of brass M6 size minimum. Alternatively, size M5 may be used, but these must be of phosphor bronze or high tensile brass.

Nuts shall be locked in position with lock nuts or lock washers, or castle-nut and split pin, or other devices if accepted. Lock washers shall not be used above M24 size except when a spring type is specially accepted.

No bolt or stud shall project through its nut by more than approximately 10 mm or four threads whichever is the less, except for terminals and relays stems.

Bolts, nuts and washers on outdoor equipment shall be of noncorroding material where they are in contact with non-ferrous parts in conductor clamps and fittings and elsewhere if specially required. Suitable special spanners shall be provided for bolts and nuts which are not properly accessible by means of an ordinary spanner.

Builders Work

Unless indicated elsewhere in this Specification, all builders work, cutting away and making good shall be carried out by the Main Contractor. The Contractor shall indicate where cutting away is required and will be held responsible for any extra costs incurred due to incorrect or inadequate marking out. Plugging of walls, floors and ceilings for the fixing of conduits, fitting and accessories shall be carried out by the Contractor.

Details of all foundations for apparatus, construction of ducts, sumps, chases, etc., structural steelwork, cutting away and making good in walls, floors, ceilings, etc., not detailed by the Engineer on the tender drawings shall be the responsibility of the Contractor who shall provide such drawings for acceptance by the Engineer.

The information shall be provided in sufficient time to allow the work generally to progress in accordance with the Contract programme, but the Contractor shall be entirely responsible for the accuracy of the information given.

External Support Brackets

All support brackets in external or unconditioned locations shall be galvanised in accordance with clause "Galvanising".

Cleaning and Painting

All ungalvanised ferrous surfaces, such as black steel pipework, internal support brackets etc. shall be painted one coat of anticorrosive primer immediately after erection, and a further two coats of gloss finish on completion.

The paint specification for all equipment supplied with a works finish shall be to suit the particular application, and shall be to the acceptance of the Engineer.

Oil and Gas

Unless otherwise specified sufficient oil or gas shall be supplied to fill oil or gas filled equipment provided under this Contract. The oil or gas shall be of appropriate type and suitable in all respects for use in the equipment when it is operated under the condition laid down in this Specification.

The design and all materials and processes used in the construction of the equipment shall be such as to reduce to a minimum the risk of development of acidity in the oil or gas. Special measures such as nitrogen sealing or the use of inhibited oils are not required unless specified by the Engineer.

Fire Precautions

All apparatus, connections and cabling shall be designed and arranged to minimise the risk of fire and any damage which might be caused in the event of fire.

Radio Interference

All equipment shall be designed so as to minimise radio interference in the frequency range 0.15 MHz to 30 MHz by means of suppression at source.


Padlocks or other accepted locking devices for circuit-breakers isolating devices, control switches, valves, marshalling kiosks, cubicles, screened enclosures and other equipment shall be supplied under this Contract.

All padlocks and other locks shall be provided with two identical operating keys. Each key shall have an engraved durable identification label. It shall be impossible to open any lock or padlock with the key of any other lock or padlock provided under this Contract. Locks or padlocks shall be in suites or areas provided with group master key facilities to the requirements of the Engineer. Keys and locks shall be impressed with the manufacturers special serial number.

Wall mounting cabinets with glazed doors suitable for the accommodation of keys, shall be provided and mounted in accepted positions and shall be labeled in a similar manner to the keys, with a labeled hook arrangement for each key. The engraving on all labels shall be in accordance with an accepted scheme.


Where specified the Contractor shall supply in steel boxes, complete with keys, any special tools that may be required for making adjustments to equipment during normal operation or maintenance periods. All tools shall be of alloy steel and stamped with an accepted identification.

Expansion Joints

Building expansion joints may occur throughout the building works. Wherever the drawings indicate that such joints are installed the Contractor shall ensure that all pipes, ducts, conduits and cables crossing the joints are suitably sleeved, set and flexibly coupled across the expansion joint, adequately fixed each side of the joint and properly bonded.

Equipment Documentation

All documentation shall be in English and shall be provided by the Contractor. The number of copies and the dates of submission of the documentation shall be provided in accordance with the requirements of the Specification.

All drawings, manuals, specifications, component lists, etc., shall have an issue or revision number and a record of modification. Equipment instruction manuals shall include circuit diagrams for each unit, plug in board and integrated circuit used in the complete equipment.

Contract Drawings

The Contract Drawings are schematic and are intended to enable the Contractor to prepare his estimates and submit a tender. Where runs of piping, ducts, cable ways etc., are shown, they do not necessarily indicate exact locations within the confines of the building area concerned. The final locations of all such services, one with another and each with the building, shall be determined by the Contractor in the preparation of his Installation Drawings. Allowance shall be made in the preparation of Tenders to cover such deviations between Contract and Installation Drawings.

Drawings Prepared by the Contractor for Construction

This section is to be read in conjunction with the Architect’s/Engineer’s conditions of contract and requirements. The more onerous specification/requirement is to be applied. Refer to the Architect’s/Engineer’s requirements for timing of submissions and for penalty clauses for non-compliance.

Further to the Schedule of Drawings submitted with the Tender, the Contractor shall, within two weeks of the order to commence work, confirm the detailed schedule of all Installation and Builders-work Drawings to be prepared by the Contractor for the purpose of constructing the Works. The Schedule shall indicate the dates on which the individual drawings shall be submitted to the Engineer for checking, date for final issue and distribution and the date on which the work covered is due to commence on site in accordance with the overall Construction Programme. Relevant dates for commencement of manufacture of plant items shall be included.

Checking of the Contractor's Installation and Builderswork Drawings by the Engineer shall not relieve the Contractor of his responsibilities for compliance with the design intent, co-ordination or with any other obligations and requirements under the Contract.

The Contractor shall allow in his Tender for providing three copies of each drawing and schedule to the Engineer for checking and four copies including reproducibles for final distribution.

All drawings prepared by suppliers, manufacturers and/or Contractors shall be endorsed with the Contractor's own name title block and drawing number and the Contractor shall take full responsibility for such drawings in accordance with his obligations The scale and format of all drawings shall be to the acceptance of the Architect/Engineer. All drawings shall be prepared on the latest version of AutoCad.

Record Documents and Drawings

This section is to be read in conjunction with the Architect’s/Engineer’s conditions of contract and requirements. The more onerous specification/requirement is to be applied. Refer to the Architect’s / Engineer’s requirements for timing of submissions and for penalty clauses for non-compliance.

The Contractor shall supply to the Engineer, as a pre-requisite to Practical Completion of the Works, comprehensive record documents finalised in detail and accepted by the Engineer. The Contractor is advised that great importance will be placed upon the quality, accuracy, clarity and completeness of the record documents and upon their being made promptly available.

Within two calendar months of completion of the work, the Contractor shall prepare and hand over to the Engineer two sets of “As Fixed” drawings and operating and maintenance instructions for acceptance. On receipt of such acceptance, the Contractor shall issue to the Engineer three final sets of drawings, comprising one complete set of translucent negatives and two sets of white dyeline prints, and three sets of operating and maintenance instructions strongly bound in flexible covers and suitable for heavy usage over a long period. The final set of documents shall also be presented on CD ROM format.

A practical completion certificate for the works will not be issued until such operating and maintenance instructions and drawings are received and accepted by the Engineer.

(a) The Contractor shall keep a full set of white prints on site showing the progress of all work in connection with this Contract. Such prints shall be kept up to date and all pipework, ductwork, conduit and cable runs, outlets positions, equipment etc. shall be marked on the prints as they are installed.

When any equipment comprises a complete installation in itself (e.g. fire alarm system), a separate set of drawings relating to that installation shall be included.

In addition to these, additional copies of detailed layouts of main plant chambers, circuit diagrams, valve charts, and relevant plant information shall also be provided suitably framed and fixed in the respective plant chambers.

(b) Operating and maintenance instructions shall be provided by the Contractor and shall comprise the following as applicable written to be read in conjunction with the Record Drawings :-

(i) A general description of the scope, purpose and manner of working to each system or apparatus forming part of the Works.

(ii) A detailed description of the scope, purpose and manner of working of each system of automatic controls and/or monitoring instruments.

(iii) Data on general design parameters and associated normal operating temperatures, pressures etc., based on the commissioning tests.

(iv) Clear and comprehensive instructions for the starting up, running and shut-down of each system or apparatus.

(v) Instructions in respect of any precautionary measures from time to time necessary (e.g. against freezing or corrosion).

(vi) Instructions in respect of the care of apparatus normally subject to seasonal disuse.

(vii) Instructions as to the nature, extent and frequency of servicing necessary properly to maintain the Works in good condition and as to the materials to be used for the purpose. This information may be supported in detail, but not replaced by maintenance instructions provided by the suppliers of particular component apparatus.

(viii) A list of recommended factory specified spare parts plus the names and addresses of suppliers of all major components of the Works as may potentially be required to obtain spare parts or replacements.

(c) Copies of manufacturer's data with respect to the nature, type and method of operation of individual pieces of equipment together with their detailed maintenance instructions shall also be supplied. Such data, in the form of individual booklets and the like, shall be indexed and cross-referenced to the operating and maintenance instructions and presented, suitably protected in box files or folders.

The Contractor shall demonstrate whenever required by the Engineer throughout the execution of the Works, that adequate and accurate records are being kept such as will ensure the ultimate completeness and accuracy of the record documents and that the record documents are themselves being progressively complied as the work on site proceeds.

The record documents shall be adequate for the following purposes :-

(i) To record clearly the arrangements of the various sections of the Works as actually installed and to identify and locate all components parts thereof.

(ii) To make it possible to comprehend the extent and purpose of the Works and the method of operation thereof.

(iii) To set out clearly the extent to which maintenance and servicing is required and how, in detail, it should be executed.

(iv) To provide sufficient and readily accessible information properly to facilitate the ordering of spares and replacements.

The format and quantities of all record documents shall be to the acceptance of the Architect/Engineer, who’s advice should be sought prior to the preparation of such documents.


The Contractor will be deemed to have, prior to tender, studied the full working drawings of the buildings, visited the site and to have acquainted himself with all relevant details affecting his work. Claims arising from neglect of this clause will not be entertained.

Protection of Unfinished Work

All unfinished work shall be left in a safe condition, and any temporary supports necessary to give adequate protection from unauthorised interference shall be provided. When it is necessary to store any heavy equipment on the site the most suitable position shall be ascertained from the Main Contractor and the equipment shall be stored in such a manner as to prevent it falling or slipping.

All trench or duct covers etc., shall be replaced on leaving the site or the immediate vicinity, and the ducts or trenches shall be adequately guarded to prevent accident.

No responsibility for protection of the works can be undertaken by the Employer.

Acceptance of Equipment and Material

All plant and material is subject to the acceptance of the Engineer, and the Contractor must submit full details, including samples where required, before placing any orders or making any deliveries to site.

All literature submitted for acceptance shall contain only relevant data.

All fire protection and prevention equipment shall be to the approval of the concerned Authority. All equipment shall be installed in strict accordance with the makers recommendations, and where appropriate shall be factory assembled and tested.

Programme of Work

Immediately after receiving instructions to proceed, the Contractor shall produce in agreement with the Main Contractor a time and progress schedule.

The Contractor shall prepare his programme on ‘PRIMAVERA Project Planner P3’ and fully integrate his programme with that of the main Contractor Copies shall be provided for the Engineer and the Employer, and a copy shall be kept on site and update his programme as necessary to maintain a completion date target programme; also as and when required by the main Contractor and/or when required by the Architect/Engineer.

Liaison with Other Parties

Telecom Authority

It is the responsibility of the Contractor to liaise with the requirements of the local Telecommunication Authority for the Telecommunications System. Prior to installation of any telephone ducts, manholes, conduits or trunking etc. the Contractor shall obtain written approval of the system and relevant drawings.

Electricity Authority

It is the responsibility of the Contractor to liaise with the requirements and regulations of the local Electricity Authority which includes the submission of a completed application form and all necessary documentation. All drawings and equipment shall be approved by the local electricity authority prior to commencement of work and all time and expenses incurred in gaining approvals shall be included in the tender.

Civil Defence Authority

It is the responsibility of the Contractor to liaise with the requirements and regulations of the local Civil Defence Authority. All relevant drawings and equipment shall be approved by the Civil Defence prior to commencement of work and all time and expenses incurred in gaining approvals shall be included in the tender.

Water Authority

It is the responsibility of the Contractor to liaise fully with the requirements and regulations of the local Water Authority for satisfactory provision of a permanent water supply. All relevant drawings and equipment shall be approved by the Water Authority prior to commencement of work and all time and expenses incurred in gaining approvals shall be included in the tender.

Drainage Authority

It is the responsibility of the Contractor to liaise fully with the requirements and regulations of the local Drainage Authority for satisfactory provision of a permanent drainage connection, septic tank and soakaway or cesspit. All relevant drawings and equipment shall be approved by the Drainage Authority prior to commencement of work and all time and expenses incurred in gaining approvals shall be included in the tender.