Construction Services
Building standards for mechanical
and electrical installations
Drawing standards and
definitions
Version 1.0 March 2013
Environment Directorate
Construction Services - Building standards for
mechanical and electrical installations
Drawing standards and definitions
Contents
1.0
Introduction
1.1
Purpose of document
1.2
Standards generally
1.3
Deviation from standards
2.0
Drawing standards and definitions generally
3.0
Drawings
3.1
Drawing Definitions
3.2
Drawings generally
3.3
Drawing co-ordination
3.4
Sketch
3.5
Sketch schematic
3.6
Detailed schematic
3.7
Technical design drawing
3.8
Detailed design drawing
3.9
Co-ordinated working drawings
3.10 Installation drawing
3.11 Manufacturer’s drawings
3.12 Builders’ work information
3.13 Builder’s work details
3.14 Record drawings
Construction Services Building standards for mechanical and electrical installations Drawing standards and definitions
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1.0
Introduction
1.1
Purpose of document
The purpose of this document is to provide information regarding Cornwall
Council’s common standards, policies and requirements for building services to
external Framework Consultants, Lead Consultants/Designers, Mechanical and
Electrical (M&E) Services Design Engineers, Design and Build Contractors, M&E
Contractors, M&E sub-Contractors, Specialists and Suppliers.
This document does not seek to replace industry-standard design guidance or
practice. It is intended to provide designers with the Council’s specific
standards and requirements, which are to be used as the basis of all building
construction.
Although this document describes particular standards it is to be read in
conjunction with all other supporting building works project specific
requirements and documentation.
External Framework Consultants, Lead Consultants/Designers, M&E Services
Design Engineers, Design and Build Contractors, M&E Contractors, M&E subContractors, Specialists and Suppliers will be expected to comply with the
following requirements when preparing any schemes for building construction
works for all new build, extensions, refurbishment, maintenance and
decommissioning works.
1.2
Standards generally
Modern construction methods offer a wide range of materials and methods to
create solutions for buildings. The majority are suitable and work well to
provide an appropriate environment for the lifespan of the project and their
efficacy can only be judged on a project-by-project basis at the design reviews
or during the approval process. However, the following is fundamental issue
which should be addressed to ensure that the preferred solution offers
compliance to the Council’s expectations.
•
1.3
Production of appropriate drawings and documentation, identifying and
measuring the works to be undertaken are essential to ensure that the
Council’s representatives can clearly identify and consider all materials,
components and services involved in the project before the works are
undertaken.
Deviation from standards
Should designers and/or providers of building construction, maintenance,
refurbishment and decommissioning works find it necessary to incorporate
alternative standards or requirements to those stated within the following
document or any other Council building construction standards then approval
shall be sought in writing from the relevant Cornwall Council representative.
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Designers and/or providers of building construction works will be required to
justify and demonstrate, with written documentation, that the alternative
proposals will provide equivalent or better performance, result in the same or
improved whole life costing and be of equal or better value.
2.0
Drawing definitions and standards generally
Cornwall Council has a significant property portfolio, which may require new,
refurbishment, maintenance or demolition works to be carried out to meet a
variety of requirements for various types of end users.
This document describes the employer’s particular requirements for the
drawing definitions and standards that M&E consultants/designers will be
responsible for completing, for mechanical and electrical services installations
for any building construction works
M&E consultants/designers are advised that any standards set by the client
team are intended to assist the design process only and the adequacy and
suitability of any information indicated there upon must be confirmed by the
consultants.
3.0
Drawings
3.1
Drawings generally
Drawings are one of the principal methods by which design information is
conveyed between members of a project team, contractors, manufacturers and
client. A number of generic drawing types for M&E building installation have
been identified by BSRIA, which are appropriate for projects of varying
complexity.
3.2
Drawing Definitions
The BSRIA technical guide provides amended definitions of the standard
drawing types and some of the different terminology being used by industry
bodies in connection with the building services aspects of a construction
project, referring to the drawing definitions as follows:The following drawing definitions are based on those given in BSRIA Building
application guide series/doc. No BG6/2009: Design framework for building
services, Design activities and drawing definitions, 2nd edition (including
correction issued dated July 2010). These definitions will be Cornwall Council’s
standard for all mechanical and electrical services installation drawings.
3.3
Drawing co-ordination
The building services designer/lead consultant shall be responsible for ensuring
that the drawings are fully co-ordinated with all other disciplines for the
purpose of construction comprising architectural, structural, ductwork,
sprinkler, mechanical and electrical services drawings.
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3.4
Sketch
Line diagrams and layouts indicating basic proposals, locations of main items
of plant, routes of main pipes, air ducts and electrical distribution in such detail
as to illustrate the incorporation of the engineering services within the project
as a whole and with respect to any zoning.
3.5
Sketch schematic
Line diagrams indicating main items of plant and their interrelationships in
such detail as to illustrate the incorporation of the engineering services within
the project as a whole.
3.6
Detailed schematic
Line diagrams describing the interconnection of components in a system
showing the engineering principles. The main features of a schematic drawing
should be as follows:
•
•
•
•
•
•
3.7
The drawings should include all functional components that make the
system work, such as ducts, pipes, cables, busbars, plant items, pumps,
fans, valves, dampers, control devices, strainers, terminals, electrical
switch gear and components, security and fire sensors and control
equipment.
Symbols and line conventions should be in accordance either with a
recognised standard, such as ISO or BS, or a supplied legend.
The drawings should be labelled with appropriate pipe, duct, busbar and
cable sizes, pressures and flow rates.
The drawings should indicate components which have sensing, control or
measurement function.
The major components indicated on the schematic drawing should be
identified for cross referencing purposes.
These details may be subject to adjustment during production information,
mobilisation and construction stages.
Technical design drawing
A drawing showing the extent of the services installations. The main features
of technical design drawings should be as follows:
•
•
•
•
Plan layouts should be to a scale of at least 1:100.
Show the extent and type of services terminals visible within the occupied
space.
Show approximate locations of horizontal and vertical service runs.
Show plant and distribution system sizes, particularly those affecting
spatial allocation, while acknowledging that these may need some
adjustment and refinement in the preparation of the detailed design
drawings and equipment schedules.
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•
Pipework and electrical containment should be represented by single line
layouts. Ductwork should be represented by either double line or single
line layouts as required to demonstrate that the routes indicated are
feasible. Symbols and line conventions should be in accordance either with
a recognised standard, such as ISO or BS, or a supplied legend.
Following discussion with RIBA in relation to the Plan of Work (2008), it is
suggested that technical design drawings be produced to RIBA Stage E. These
drawings will show how space within risers and service zones is allocated to
ductwork (using calculated, but still approximate, duct sizes), pipework
(showing the number of pipes to be accommodated but only approximate
diameters including insulation), and cabling (showing the size of electrical
containment rather than individual cables).
3.8
Detailed design drawing
A drawing showing the intended locations of plant items and service routes in
such detail as to indicate the design intent. The main features of detailed
design drawings should be as follows:
•
•
3.9
Plan layouts should be to scale of at least 1:100. Plant areas should be to
a scale of at least 1:50, and should be accompanied by cross sections.
The drawing will not indicate the precise position of services, but it should
nevertheless be feasible to install the services within the general routes
indicated. It will be possible to produce coordinated working drawings or
installations drawings without major rerouting of services.
Co-ordinated working drawings
Drawings showing the interrelationship of two or more engineering services
and their relation to the structure and building fabric. The main features of
coordination drawing should be as follows:
•
•
•
•
•
Plan layouts should be to a scale of at least 1:50 and be accompanied by
cross sections to a scale of a least 1:20 for all congested areas.
The drawings should make allowance for installation working space and
space to facilitate commissioning and maintenance.
The drawing should be spatially coordinated and there should be no
physical clashes between the system components when installed. Critical
dimensions, datum levels and invert levels should be provided.
The spaces between pipe and duct runs shown on the drawing should make
allowance for the service at its widest point. Insulation, standard fitting
dimensions and joint widths should therefore have been allowed on the
drawing.
The drawing should indicate positions of main fixing points and supports
where they have significance to the structural design or spatial constraints.
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3.10 Installation drawings
A drawing based on the detailed design drawing or coordinated working
drawing with the primary purpose of defining that information needed by the
tradesmen on site to install the works. The main features of installation
drawings should be as per coordinated working drawings, plus:
•
•
•
Allowances should be made for inclusion of all supports and fixings
necessary to install the works.
The drawing should make allowances for installation details provided from
manufacturers’ drawings.
Allowances should be made for plant and equipment. This includes any
alternatives to the designer’s original specified option that have been
chosen.
Where no co-ordinated working drawings have been produced, the installation
drawing shall include co-ordination.
3.11 Manufacturer’s drawings
Drawing prepared by a manufacturer, fabricator or supplier for a particular
project, and which is unique to that project. Examples include drawings for
ductwork, pre-fabricated pipework, sprinkler systems, control and switchgear
panels and associated internal wiring, pre-fabricated plant, customised plant
and equipment.
3.12 Builders’ work information
A drawing to show the provisions required to accommodate the engineering
services which significantly affect the design of the building structure, fabric
and external works. Also drawings (or schedules) of work to be carried out by
building trade, and required to be costed at the design stage such as plant
bases.
The critical criterion with builders’ work information is that it includes all
openings (or other provisions) which significantly affect structure, fabric or
external works. The minimum dimension of these openings needs to be agreed
among the project team.
3.13 Builder’s work details
Drawing to show requirements for building works necessary to facilitate the
installation of the engineering services.
Unless agreed otherwise, the following builders’ work details can be marked
out on site:
•
•
•
Holes less than the threshold dimension agreed by the team
Electrical socket and switch boxes
Openings that are best cut into blockwork and partitions
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Builders’ work details carry forward and confirm or refine the structurally
significant items from the builders’ work information, and also introduce new
items that are not structurally significant, such as plinth dimensions for the
actual plant items ordered.
3.14 Record drawings
The record drawings shall include all additions to, deductions from, or
variations made to the scheme during progress of the works
Drawing showing the building and services installations as installed at the date
of practical completion. The main features of the record drawings should be as
follows:
•
•
•
•
•
The drawings should be to a scale not less than that of the installation
drawings.
Locations of all the mechanical, electrical and public health systems and
components installed including ducts, pipes, cables, busbars, plant items,
pumps, fans, valves, dampers, control devices, strainers, terminals,
electrical switchgear and components, security and fire sensors and control
equipment.
The drawing should be labelled with appropriate pipe, duct and cable sizes,
pressures and flow rates.
The drawings should have marked on them positions of access points for
operating and maintenance purposes.
The drawings should not be dimensioned unless the inclusion of a
dimension is considered necessary for location.
Prepared by:
Strategic Planning and Standards
Property Services
email sp&s@cornwall.gov.uk
Draft
1.0
Date
03/03/13
Prepared By
SPAS
Construction Services Building standards for mechanical and electrical installations Drawing standards and definitions
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If you would like this information
in another format please contact:
Cornwall Council
County Hall
Treyew Road
Truro TR1 3AY
Telephone: 0300 1234 100
Email: enquiries@cornwall.gov.uk
www.cornwall.gov.uk
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