Working drawing management
Prior to this chapter production information has been the primary concern. It is this information—both drawings and specification—which represents the final commitment to paper of planning and constructional decisions arrived at during the earlier stages of the project. This final documentation is inevitably a time-consuming process, and if it is to be carried through smoothly and economically it is important that all the necessary decisions should have been taken before its commencement.
It is also true to say that of all the aspects of an architect's work it is this final documentation that lends itself best to the deployment of a team. On very few projects will there be the time available to allow the working drawings to be prepared by a single individual, and in practice even quite small buildings will involve more than one person at this stage.
The objective, therefore, is the achievement of a rapid, well-programmed draw-up, in which the information to be documented by each member of the team is allocated in advance with due reference to his experience and ability, and during which only the most routine and undemanding of technical problems should remain for resolution. In order to achieve this it is important that a more or less rigid adherence to the plan of work is maintained.
The RIBA Plan ofWork was illustrated in chapter 1 as constituting the basic discipline within which the manifold activities of the architect are contained. Against each stage have been noted the major aspects of work dealt with at that stage which will have a bearing on the working drawing process, or which will be influenced by it.
The plan of work is sometimes criticised as being doctrinaire and unrelated to the harsh facts of professional life. Certainly in practice there are constant pressures to do things out of sequence because there is a short-term benefit to be gained by doing so. It is very tempting when struggling with knotty problems of detailing, or seemingly lethargic fellow consultants, to take the view that a premature start on the final drawings will in some way have a cathartic effect on the enterprise.
But 'time spent on reconnaissance is seldom wasted' is a military adage that is valid in other fields; a proper laying of the groundwork will help to avoid those drawing office crises, destructive alike of morale and financial budgeting, when a team of several people is brought to a standstill by the sudden realisation of some unresolved problem.
From the standpoint of stage F then let us first look back to the preceding stages, where a little forethought will make life in the subsequent stages a great deal easier.
Pre-requisites for stage F
There is a basic minimum of information which needs to be available before embarking on stage F, and this should certainly include the following:
• final design set of drawings (stage D)
• record of statutory approvals (stages D and E)
• outline specification
• applicable trade literature
• library of standard details
• drawing register
• design team network
• drawing office programme.
These items are dealt with in detail below.
Final design set (stage D)
It will always be necessary to produce a properly drawn set of drawings showing the final design, and if subsequent changes are called for, no matter how minor, it is sensible to record these on the negatives themselves rather than in any other form, so that at any one time there exists an up-to-date record, and confirmation, of what has been agreed with the client. Obviously these will be presentation drawings, prepared in the manner best calculated to obtain the client's approval. Nevertheless before the trees and the shadows are added, it is prudent to take a set of copy negatives from the unadorned masters, for then definitive plans and elevations will be available which may be issued immediately to other consultants on commencement of stage E, and the rather fruitless business often encountered of re-drawing the whole scheme as 'draft working drawings' once design approval has been obtained may be eliminated, with benefit to both office economics and programme.
This implies, of course, that the scales and draughting techniques adopted should be compatible with use for both purposes, but this is quite feasible if the subsequent use is borne in mind from the outset (5.1 and 5.2).
The use of CAD renders this whole process much simpler and of even more economic benefit. The final design plans, denuded of their extraneous trees and shadows, will serve directly as the master negative for subsequent elementalisation, with the decorative presentation features existing as an additional layer in the set.
A chicken and egg situation, this one—you can't get approval until you've submitted the drawing: you can't prepare the drawing until you've got approval. But visits to the fire officer and the building inspector in the early stages of the scheme will not only set up lines of communication which will be invaluable for the future, but will establish principles for incorporation in subsequent detailing. It is a firming-up process. It is essential to know at the start of stage C the spacing of escape stairs the fire officer will demand, and by the end of it their widths. It is essential to know before the end of stage E the required fire rating of all doors. Nobody should need to raise such questions in the middle of stage F.
The decision and agreements must be recorded, of course, and it is obviously more helpful to give someone a marked up drawing to work from than a bulky file to read. The final design drawings referred to above as being issued to consultants form an obvious basis for the recording of this sort of information (5.3).
Key detailing in draft (stage E)
At the completion of stage E there should be a carefully thought out solution available for every construction problem that can be envisaged, and this will involve the production of a sheaf of draft details in which the principles of these solutions are established.
The drafts will not be elaborated into final drawings. They will remain as source documents, and the decisions they embody will be fed out into various stage F drawings—location sections, assemblies and component details—and the specification.
It should be noted in particular how the one draft assembly section generates a whole series of detailed statements about various aspects of the building. In an earlier day it might have been thought adequate to issue the section as a final drawing, a 'typical detail' from which the operative might be expected to infer detailed variations to suit differing but basically similar situations throughout the building. In today's very different conditions this is just not adequate.
It is, however, reasonable to expect a drawing office assistant to apply the principles involved to other aspects of the building, which he will either identify or which will be identified for him by others with greater experience or knowledge of the particular building.
This approach to detailing, whereby the basic principles of construction are established by the principal or the project architect but are translated into detailed practice by an assistant, lends itself to considerable drawing office economies. By defining the necessary drawing office tasks at the outset of the programme (a subject which will be dealt with in detail later) the appropriate level of responsibility may be set for all members of the team.
The advantages of room by room scheduling as a medium for conveying information about internal finishes and fittings have been noted earlier. The gradual collection during stage E of such information into a source document of comparable format will clearly assist in the preparation of such schedules at stage F. Whether this is done on a print of the floor plan, or on a series of individual sheets representing each room or room type is a decision which will be made in the light of the size and complexity of the individual project. At the end of the day there will exist, hopefully, a complete record of each room's requirements, with indications where applicable as to the authority for those requirements, serving alike as a detailed record of client instructions and a briefing manual and check list when the final documentation is being prepared. (See also 5.3.)
The case is argued elsewhere in this handbook for a specification which is an integral part of the production documentation rather than the afterthought which puzzled foremen often assume it to have been. If drawings are to be freed of the detailed written descriptions they are frequently made to carry, it is implicit that this information must be conveyed to the contractor by other means. Indeed, the philosophy of the National Building Specification is reliant upon the geometry of the building and of its component parts being covered by the drawings, with selection from alternative materials and definition of quality standards being covered by the specification.
It is desirable therefore that both drawings and specification should draw their information from a common source document, and that this document should be produced before the stage F programme gets under way.
The outline specification is a useful format for this document, partly because something approaching it will
5.2 Copy negative taken from 5.1 before the blandishments were added. Scale and simple draughting make it suitable for issue to consultants for preparation of their own scheme drawings
5.3 Print taken from 5.2 and marked up as a briefing guide to the drawing office at Stage E 104
have been needed by the quantity surveyor for his final design stage cost check to have any validity. It consists basically of a check list (CI/SfB elemental order is a convenient framework) upon which decisions on construction and materials may be noted as they are made.
Formalising these decisions into such a document at an early stage ensures that they are made at the proper level of experience. Readers of The Honeywood File will recall Ridoppo, the wonder paint that crept off the walls and out of the house. We have all had our Ridoppos, but at least it ought to be possible to ensure that they are not selected by the drawing office junior at the last minute because time was short and nobody had told him any better.
The rationalised drawing structure provides a convenient framework on which to hang manufacturers' literature. There is no virtue in redrawing the builders' work details printed in Bloggs & Company's catalogue when a photocopy suitably overcoded with the job and drawing number will convey the information more cheaply and accurately. (Bloggs & Company are not likely to object to the resultant wider distribution of their literature.)
But in any case the literature which it is known will be required, if only as source documents for one's own drawings, should be assembled early in the day. It can be frustrating to have to interrupt work on a detail to telephone for urgently needed trade literature and then wait two or three days for its arrival (5.4).
Library of standard details A lot of practices attempt at some point in their existence to crystallise the accumulated wisdom and experience of the practice into a set of standard details, only to find with increasing disillusionment as they proceed that not nearly so much is really standard as was at first supposed, and that the very existence of a
CURBS: SQUARE and RECTANGULAR TIMBER CURBS
Dwarf ventilator ■ timber or concrete curb Lantern lights • timber or concrete curb
5.4 Manufacturer's catalogue giving precise fixing details. It is pointless to re-draw this information when the catalogue can be issued to the contractor as an instruction
1 Advise teem of outcome of Stage 0 report.
2 Maintain end co-ortbnate progress
3 Provide outstanding information, »voiding iboniw «work.
5 Up-date St«ga D information for briefing m—ting
0 Up-date Stage 0 infonnatk>n for briefing meeting 7 Up-date Stag* 0 information for briefing meeting. 8* Up-date Stage D information for briefing m—ting
9 State policy requirements for construction and finishes 1Q Confirm tender and contract policies. 11 Convene briefing meeting.
1 2 Review Job Control Han lor this stage . 3 Prepare draft activity programma.
l-^Hoid briefing meeting and agree the following: rotea and v responsibilities : elements for detail design : protect divisions : scales for location drawings.
15 Corréete location drawings to agreed scat« and distribute
16 Decide eN matters put up for decision si any time.
1 7 Prepare detailed work analysis.
18 Prepare detailed work analysis
19 Prepare detailed work analysis ¿0 Complete activity programme
2 V> Hold programme meeting. Discuss work analysts, location drawings.
agree element solutions and alternatives 22 Explore solutions in collaboration with team >3 Explore solutions in collaboration with team ¿4 Explore solutions in collaboration with team 2 5 Consult suppliers and manufacturers as necessary 26 Cost check alternatives and compare with cost plan. 2.7 Consider alternatives and report to meeting >S> Hold meeting to agree solutions for development. Eliminate alternatives.
29 Obtain approval as necessary to selected solutions. Î0 Hold further consultation with statutory authorities on principles of construction.
$1 Provide team with preliminary information on adopted solution
32 Provide team with preliminary information orv adoptad solution
33 Provide team with preliminary information on adopted solution
34 Develop solutions with typical details in collaboration with team
35 Develop solutions with typical details in collaboration with team
36 Develop solutions with typical details in collaboration with team
37 Obtain preliminary estimates as necessaiy
38 Co-ordinate information and add to location drawings
39 Cost check developed solutions (main cost check)
40 Discuss and agree developed solutions and cost
41 Receive details of final cost check if necessary
42 Prepare outstanding specification clauses
43 Adjust if necessary and finalise all details including layout drawings
44 Adjust if necessary and finalise all datails including layout drawings
45 Adfust if necessary and finalise all details including layout drawings
46 Co-ordinate information and add to location drawings
47 Adjust costs as necessary 4B> Review final drawings and cost •¿9 Collect and check all final drawings
50 Apply for Building Regulations approval
51 Review planning consent and re-apply >f necessary
52 Agree or confirm : contract conditions procedure of information to tender, list of contractors and nominated sub contractors, advance ordering a.g demolition, piling steelwork, etc
53 Prepare proposals for sequence of information required for B of Qs tB4>Hold briefing meeting and agree: rules and responsibilities, drawing format, scale, practical divisions. use of copy negatives: genersl requirements for cost flow: review ot outstanding Approvals and Consents : review of Job Control Plan 55 Prepare and distribute draft activity programme for Stage F Study draft Stage F programme and orepare comments Hold bnefing meeting. Consider and agree or amend draft act>v*tv programma 58 Finalise activity programme and distribute
5.5 Precedence diagram (taken from the RIBA Management Handbook). It has the advantage that it offers a rapid assessment of the consequences of any programme change, by its compatibility with computer analysis standard drawing which is nearly (but not quite) applicable to the project in hand is a dangerous inducement to compromise.
On the other hand it is frustrating to realise that the detail being worked out laboriously in one room for project A is not going to end up significantly different from the detail simultaneously being worked up across the corridor for project B. There should be room somewhere for a common-sense approach which does not attempt too much.
In practice few assembly details can be drawn so 'neutrally' as to render them directly re-usable on more
1977 1978 1979
1977 1978 1979
than one project. The best that can be achieved in this field is to collect together drawings for various projects which embody solutions to recurring problems of principle, making them available for reference rather than direct re-use.
Component drawings are another matter, however, and provided that the office is using a structured drawing method it should be possible for each project to contribute its quota of contractor-made components (there is no point in re-drawing proprietary items) to a central library. Such components as door-sets, shelving, cupboard fitments and external works items—bollards, fencing, etc—are suitable subjects for treatment.
The details, once selected for a standard library, should sensibly be re-numbered to ensure that when re-used on new projects they do not conflict with the numbering sequence for that project. C(32)501 for example might well be the first drawing in a library of internal joinery components, and would not conflict with component details specific to the project and numbered C(32)001, etc.
The use of CAD raises other issues. The ease with which details stored electronically may be altered means that assembly drawings may also form part of a standard vocabulary.
It is essential for the work of the entire design team to be integrated into a comprehensive programme, and unless a specialist programmer forms part of the team (and this is almost a sine qua non for any very large or complex projects) then the management role of team co-ordinator falls to the architect. Of all the consultant team he is probably best fitted by virtue of his training and his other duties to exercise the skills required, and should take advantage of his position as team leader to establish the appropriate procedures at the outset (see the section 'Design team meeting' on p 120).
In setting down the programme on paper, it will be found that a simple network is the best format, where the dependencies of the various team members upon each other may need to be shown. The format suggested in the RIBA Management Handbook Guide on Resource Control is one way to do it (5.5).
Its complexity may be unnecessarily daunting for the small to medium size project, however, particularly when a non-technical client is involved (the method is best suited to computer analysis and critical path method which may not be available). A simplified version on which a visual time scale has been superimposed will serve the same purpose in most cases (5.6).
The point to be reiterated is that every job, no matter how small, benefits from thoughtful programming, and
Table IV A typical range of CI/SfB codes used on a large project
(2-) primary elements
secondary finishes elements
(30) site secondary elements
ext int wall wall openings openings
(8-) loose equipment
general special room loose loose equipment equipment
(20) site primary elements
(21) external walls
sire general sanitary fixtures room fixtures fixtures
This band will normally be used for location drawings and a large number of the assembly drawings on small projects; for basic location plans (le before process negatives are taken) on large projects
This band will normally cover the elementalised location plans on most projects. It will also he used for assembly and component coding on small projects
This band will normally cover assembly and component details and schedules on most projects, but may well be found unnecessarily detailed for small projects the things to watch which are common to any method you use are:
• Restrict the network to as few activities as you reasonably can, paying particular attention to those activities whose completion is a pre-requisite for subsequent action by others. The purpose of the network is to provide each member of the team with basic management information. (He may well wish to develop for his own purposes a more detailed network of his own activities within the team management's framework.)
• Draw it simply. Its value as a document is that it can respond rapidly to a changed situation, and it must always be a realistic statement of the current position if it is to retain its credibility. It is no use having a programme drawn so beautifully that no one has the heart to re-draw it when it becomes out of date.
• Involve the client. Many of his activities are critical ones, particularly his formal approvals at various stages in the design, and he must be made aware of his responsibilities at the outset, along with the other members of the design team.
The structure of the final production set of drawings is central to both the smooth running of the project on site and the economics of the office producing it. It must therefore be considered in some detail.
Location plans: Given that the set is to be structured in the manner recommended in the earlier chapters the first decision to be made (and as noted earlier it will have been sensible to make it before preparation of the final design drawings) relates to sheet size and scale of the location plans. Basically the choice lies between a scale of 1:50, permitting a relatively large amount of information to be conveyed on a single sheet, or 1:100 where a greater degree of elementalisation will be required if the sheet is to remain uncluttered and legible, and where its main purpose is to provide a ready indication of where other and more detailed information is to be found.
A number of considerations will determine this decision, but they will centre around the size and complexity of the project. Housing and conversions are normally best carried out at the larger scale. Larger projects are often better suited to an elementalised set of 1:100 plans. This is partly because it allows reference back to detailed information which in many cases will be repetitive and which it would be uneconomical to redraw several times, and partly because it makes it easier to deploy a drawing team.
So most projects on which more than one draughtsman is likely to be engaged will benefit from the latter approach.
In the discussion that follows it will be assumed that a single multi-storied building of some £500,000 contract value is being dealt with, that a drawing team of three/four people will be involved, and that the decision has been made to produce 1:100 location plans, elementalised for clarity.
The first allocation of sheets therefore will be to location plans, one sheet for each plan level. They will be coded L(—) ie 'The project in general', because they are the basic drawings from which will be taken the copy negatives which will form the basis for subsequent elemental development. (As has been noted in chapter 2, numbering of those plans by floor levels is a refinement which, apart from possessing a certain elegance for the system-minded, offers eventual benefits to the site staff.)
The basic plans having been established it is necessary to
5.7 A print of the elevation has been used to identify every section through the external walls where the construction changes (seep. Ill)
Peter Leach Associates
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