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Drawings guide

It is no use preparing your drawings on a well structured and carefully thought out basis if you are the only one who knows about it. Until such time as a standard drawing method becomes universally employed and recognised throughout the building industry—and despite the increasing emphasis being laid on the Co-ordinated Project Information documents previously referred to we are still a long way from that—it is incumbent on the producing office to give clear directions as to how its drawings may best be used.

Instruction must take two forms if it is to be effective. There must be a verbal explanation of the method, when the building team is shown the search pattern for information. The initial site meeting is a useful venue for this. There must also be a written guide for subsequent reference, and this will be a useful document to bind into the office manual. Newcomers to the office need to know how the office method works.

An office manual which embodies the drawing and coding methods advocated in this handbook could be prepared for use by members of the office, other consultants and contractors alike. It might be set out as shown below.

Other consultants' drawings

Little has been said so far about the drawings of other consultants and it may be appropriate to comment here on the problems of liaison and co-ordination of drawings produced outside the architect's immediate control. Part of the difficulty arises from the fact that neither the structural engineer nor his M & E counterpart really produces production drawings in the strict sense of the term as it has been used here, ie as a definitive instruction to the builder. Each produces traditionally what is in effect a design drawing, relying on others to provide supplementary information for construction purposes. For example, the structural engineer constantly relies on the architect's drawings to convey such fundamental information as chases in upstand beams for asphalt, throatings in soffits, and the required finish for exposed in situ concrete. The M & E consultant is more often than not unable to provide information on, for example, holding down bolts, because the position of these is dependent upon a plant

A guide to these drawings

The drawings in this project have been arranged in the following manner:

1.0 All information in the drawing set is divided into five basic categories of drawing. These are:

• Location drawing (coded L) showing where anything is—eg where a particular window is located in the building.

• Component drawing (coded C) showing what it is—eg what the window looks like, how big, etc.

• Assembly drawing (coded A) showing how it is incorporated in the building—eg how the window relates to the lintol and the till, and to the wall in which it is built.

• Sub-component drawing (coded SC) showing the detailed construction of each component—eg the section of the window frame.

• Information drawing (coded IN) giving supplementary information which is relevant, but not part of the building—eg survey drawings, bqre hole analyses, etc.

2.0 Each category is then divided into broad sections or elements, each of which deals with a particular work stage. The codes for these are given in brackets following the drawing category, as follows: (1-) Substructure (2-) Primary elements

(3-) Secondary elements

(ie walls, floors, roofs, stairs, frames)

(ie everything filling openings in walls, floors and roofs, suspended ceilings and balustrades)

(8-) Loose equipment

(ie sanitary fittings, cupboards, shelving, etc)

(ie fire extinguishers, unfixed furniture, etc) (ie information of a general nature which cannot readily be allocated to any of the other elements).

Drawing category

Location

3.0 All of these codes will not necessarily be used on any project. A list of the elements into which the present set is divided is given at the end of this guide. The element will always be recognisable from the drawing number box however. For example:

L(2-)003 is a location drawing and deals with the positioning and referencing of primary elements. It is the third drawing in that series. C(3-)012 is a component drawing, and is of a secondary element component, such as a door, or a rooflight. It is the twelfth drawing in that series.

4.0 One further sub-division is built into the system. C(3-) indicates that the drawing deals with a secondary element component. C(32), however, indicates that it is a secondary component in an internal wall, and C(37) that it is a secondary element in a roof. A complete table (known as CI/SfB table I) is given below. Once again all these sub-divisions will not necessarily appear in this drawing set. Furthermore you may well find a location drawing coded L(3-) covering all secondary elements, but containing on it references to component drawings C(31), C(32), C(37), etc. This is so that component drawings relating to windows, internal doors and rooflights respectively may be grouped together for easy reference.

Component

Assembly

Schedule

Code Information conveyed

L General arrangement plans and elevations, locating all major building elements (walls, doors, windows, etc) and indicating where more detailed information may be found.

Showing the size and appearance of all components (eg windows, doors, shutters, fitments, cupboards, etc).

Demonstrating the manner in which the various building elements and components fit together. Storey sections through external walls, are an obvious instance.

Providing an index to the retrieval of information from other sources.

Sub-component SC

Information IN

Showing the manner in which a component is made, eg a timber window would be treated as a component, but sections of the frame, glazing, beads, etc would be the subject of an 'SC' drawing.

Giving background information to the project—survey information, bore holes, pictorials, drawing schedules, etc.

manufacturer who may not have been selected at the time he considered his drawing effort complete. So 'See architect's detail' appears on the structural engineer's drawing (if we are lucky) and 'See manufacturer's shop drawing for setting out of pockets' is frequently the best that can be achieved by M & E. Neither is very satisfactory yet the difficulties in effecting an improvement are substantial, for both spring from an historical and artificial fragmentation of the building process; in the first instance a fragmentation of professional disciplines, in the second an unnatural alienation of the designer and the constructor.

Changing roles

Changing the roles of the profession and the industry may well be desirable, but it is a long-term process and not the function of this book. The best must be made of the present situation. It is therefore incumbent on the architect to acknowledge his management function as co-ordinator of the professional team, and he must accept responsibility for ensuring that the structural engineer is aware of M & E requirements, and that M & E are equally aware of structural constraints. In an imperfect world nobody else is going to do this.

Elemental drawings

Another consideration must be that if we are dealing, as is proposed, with a largely elemental set of drawings as an aid to communication between designer and operative, then it ought to be made possible for a carpenter to build his formwork from the structural engineer's drawings alone, without the need to refer to drawings prepared by others for information which may be vital to him.

Requirement of a formal meeting It is well for drawings to be prepared by other consultants to be agreed at a formal meeting, which can be minuted, and clearly the architect is in a better position if he has firm proposals and methods worked out to put to the meeting than if he throws the meeting open to suggestions from all sides.

Design team meeting

Such a meeting should cover the following points:

1. Introductions Individuals in each organisation must be named as the link men through whom information is to be channelled. They should be of sufficient standing to be able to act and make decisions responsibly and with authority and, if possible, they should be of comparable seniority within their own organisations. It is unhelpful to the project for a young project architect to be out-gunned by the senior partner of the structural engineering consultants.

2. Procedures The means by which all team members are to be kept informed must be established. There is no necessity for the architect to insist on acting as a post office, nor need he insist on being party to day-to-day discussions between other consultants, but it is vital that he be kept informed of the outcome of such discussions and that all drawing exchanges are copied to him.

3. Programme An example of a programme for the design team has been given in 5.6. Table it, but do not insist unreasonably on its detailed initial acceptance by other team members against their better judgement. It must at all costs be realistic. But once it has been accepted, it must be taken seriously. Tongue-in-cheek agreement with one eye on an escape route when the inevitable problems occur can be a costly business for everyone.

4. Format Thought should have been given at the design stage of the project to the question of suitable production drawing scales and sizes, so the architect should be well prepared to table his proposals for the format. Consistency between all drawing-producing offices is important. Apart from the demonstrable advantages of enabling copy negatives of the architect's basic drawings to be used by other consultants and the reduction of storage and retrieval problems on site, the indefinable air of authority generated by a well organised set of drawings and the impression given of a team well in control of affairs all help in promoting confidence in the team among both outsiders and its own members.

Note that the desirability of maintaining a consistent format applies equally to computer aided drawings. With the possible exception of drawings transmitted electronically—and while the Layer Naming Convention noted above makes this a practical possibility it is still something of a rarity for most offices—communication between offices will be by means of drawings in the form of hard copies on paper.

5. Coding of drawings It is not essential for all consultants to follow the structuring and coding disciplines that the architect imposes on himself, but nevertheless it is highly desirable that they should be persuaded to do so. In practice it should not be very onerous. All disciplines have their equivalent of the location drawing and all use schedules. These are worth bringing into the structuring method, even though the structural engineer may still adopt his traditional practice of inserting larger scale sections on his general arrangement drawings. If CI/SfB is in use then blanket codes of (16) Foundations and (28) Frame for structural drawings and of (5-) Services and (6-) Installations for services engineers' drawings provide a simple expedient for bringing all disciplines within a common retrieval framework without launching others on to waters the depth of which the architect himself may not yet have plumbed fully.

6. Definition of responsibilities Many defects, both of omission and of overlapping information, may be avoided if the responsibilities of each team member can be defined precisely at the outset of the project. Apart from the more straightforward contractual responsibilities which it is assumed will have been covered in the respective letters of appointment but which it will be sensible to confirm at this inaugural meeting (matters such as, for example, who tackles lifts, cold water supply, drainage, roads and footpaths; who details and checks pre-cast concrete components, etc) there are grey areas where some early agreement will be of benefit. The allocation to the structural drawing office of the responsibility for indicating accurately detailed profiles has already been referred to. Reinforced concrete staircases provide another area where it is unnecessary and confusing for the architect to prepare elaborately detailed sections for the benefit of a contractor who is going to build from the structural engineer's drawings anyway. An early agreement should be reached to limit the architect's role to providing design profiles within which the structural engineer may work, and against which the structural details may be checked subsequently.

Drawing office programming

The design team programme will have identified the time available for production of the working drawings, and the first shot at the drawing register will have revealed the magnitude of the task. The reconciliation of one with the other, and of both with the financial resources available, is one of the essential arts of architectural management, and as such demands more space than can be devoted to it in the present handbook. Certain points may usefully be made however.

Size of drawing office team

The right size and structure of the team is all-important, and in many ways it is a case of the smaller the better. Any increase over a team of one starts to invoke the law of diminishing returns and as the numbers increase so do the problems of control and communications. On the other hand, the diversity of work demanded by most building projects coupled with the constant and remorseless pressures of the overall programme mean that too small a team lacks the necessary flexibility of response.

In practical terms, the size of the team will be the size of the task in man-weeks divided by the number of weeks available, and if the latter is unreasonably low then the team becomes unwieldy and difficult to co-ordinate. In any case, the size of the team is bound to fluctuate throughout the working drawing period, with a small but high-powered element at stage E, rising to a peak soon after commencement of stage F, and tailing off towards the end of that stage as the main flow of information to the quantity surveyor is completed (5.12).

When the office is working with CAD it is possible for more than one drawing position to be linked to the printer/plotter, which may well be inoperative for long periods. Unless the team is very small and its members are in constant touch with one another it is essential to have some some form of unified control so that the printer/plotter is not operated from two drawing positions simultaneously.

Production drawing programme

The production drawings, if properly structured so that a predetermined amount of information is conveyed in them, should be the simplest aspect of the architect's work to quantify in terms of time taken. Having established the list of drawings, it is better for two of the more experienced people to make independent assessments of the time that should be taken over each drawing and to compare notes afterwards. Factors of personal optimism or pessimism may thus be discounted, and a more realistic time allocation made. But experience is everything, and an inquest after the programme has been completed, with feedback of the actual time taken over each drawing as against the time budgeted for, is essential if future programmes are to be timed more accurately.

Priorities

In framing the stage F programme certain priorities will emerge. Clearly the establishment of the basic set of location plan negatives is fundamental, for they will form the basis for elementalisation of subsequent location plans and of other consultants' work. After that the priorities will probably be dictated by the needs of the quantity surveyor. An elemental format makes it easier to group the issue of drawings into separate packages—eg internal joinery, finishes, etc, but this is only helpful if the packages are genuinely complete. Few quantity surveyors will object to receiving information' piecemeal, but an early issue of the openings schedule, with half the details it refers to still incomplete, only leads to an abortive start being made on the measurement. On the other hand, the fact that drawings of the basic structure may be issued and measured without having to wait for the finishes to be added to the same sheet does allow a bigger overlap of the production drawings and billing programmes.

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5.12 This histogram, taken from the records of an actual project, shows the difficulties of co-ordinating multi-disciplinary efforts. The peaking of resources during the production drawing stage is clearly shown

struct engineer mie mech rait elect m&e drainage

5.12 This histogram, taken from the records of an actual project, shows the difficulties of co-ordinating multi-disciplinary efforts. The peaking of resources during the production drawing stage is clearly shown

Drawings should be allocated to team members in the form of a simple bar chart. By this means, everyone can see his personal short-term and long-term targets, and a competitive element may be introduced (5.13).

Introducing new methods

The introduction of structured drawings into an office which hitherto has managed without them requires some thought. There must be many offices which, whilst agreeing in principle that their work could be improved by rationalisation of their working drawing methods, are reluctant to take the first step on what might prove to be a seductively attractive slippery slope.

As with dieting and daily exercising the two important things are to start today rather than tomorrow and not to be put off by the prophecies of failure which will be made by those around you. In this latter respect, one common fallacy may be dispelled at the outset. You will be told confidently that architects are individualists and will fight tooth and nail against any suggestion of rationalised drawing, standardised detailing or mathematically oriented coding systems. This you will find to be untrue, architects being as fundamentally lazy and anxious for a trouble-free existence as anyone else. Experience indicates that given a commonsense system which is fundamentally easy to use, people will use it.

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