The information shown on a locating drawing will be overall sizes, levels and references to assembly drawings. They are intended to show the location of the works, not detail (a common mistake). The location drawings, which can be plans, elevation or sections, are numbered consecutively with the prefix L.
British Standard Specification 1192 includes recommended or preferred scales for location drawings.
Block plans usually show the siting of the project in relation to Ordnance Survey Maps. Conventions are used to depict boundaries, roads and other details. Recommended scales are:
- 1 : 2500
- 1 : 1250
- 1 : 500
- The location of the building or buildings in relation to their surroundings.
- The topography of the site, with both existing and finished levels.
- Buildings to be demolished or removed.
- Roads, footpaths, hardstandings and paved areas.
- The layout of external service runs, including drainage, water, gas, electricity, telephone, etc.
- The layout of external lighting.
- Fencing, walls and gates.
- The location of miscellaneous external components – bollards, litter bins, etc.
Floor plans usually show the layout of rooms, key dimensions and levels, and may also use conventions and symbols to show materials and locations of fittings and appliances. Recommended scales are:
- 1 : 200
- 1 : 100
- 1 : 50
Line types are used to differentiate information in floor plans. Hatching or conventions are used to illustrate materials, while symbols are used to show fittings and appliances, often with standard abbreviations.
There are three situations that must be considered:
- General arrangement (location) drawings designed to show a single building element and what it should contain.
- Basic floor plan drawings – the drawings which provide the fundamental and minimal information which will appear as the framework for each individual elemental plan. The basic drawing, in fact, from which future drawing containing elemental information will be taken.
Basic floor plan
(2-) Primary elements
General arrangement plans
Where the elemental plans are to be drawn by CAD or manually, you must fist consider what common features of the plans will need to appear in all five elementalised plans given in the example above. It is clearly important that the information carried by the base negative, (manual) or layers common to all drawings in a CAD set shall be, not too little, and not too much. Below is a check list of what the basic plan should contain and a list of those items which more often than not get added to the original needlessly and superfluously to the subsequent inconvenience of everyone.
To be included:
- Door swing
- Room names and numbers
- Grid references (when applicable)
- Fixed furniture (including loose furniture where its disposition in a room is predetermined - e.g. desks set out on a modular gird, etc.)
- North point
Items which tend to be included, but should not be:
- Hatching and shading
- Loose furniture where its disposition is not predetermined
- Section indications
Elevations usually show the outline of the building, opening details and sizes, level datums and floor position. An elevation should give an impression of how one face of the building will look from the outside.
Estate road layout
Should be at either 1:1250 or 1:500 scales. Line types will fulfil an important role in this type of location drawing. The identity of buried items will be indicated by different line types. Conventions and symbols will indicate hard and soft landscape details and street furniture should be indicated by symbols.
The purpose of assembly drawings is to show how the building is erected on site. Information will include component identification and reference, assembly dimensions and tolerances with reference to component drawings.
The assembly drawing number is prefixed by the letter A. Standard details need an efficient library coding system to aid retrieval and sorting, and the Common Arrangement of Work Section (CAWS) reference system found in the standard old Method of Measurement (SMM7 - now replaced by the NMR2 and Uniclass). Some assembly drawings will show:
- External wall details
- Wall openings such as head, sill and jamb sections, plans
- Eaves details
- Internal walls
- Stair details
The structuring of drawn information into specific sheets helps the search patterns of the end user. Some unenlightened designers will fill the drawing sheet with a mixture of plans, elevations and, if there is room, detailed sections. The titled chosen for the drawing sheet is the first indication of the content of the sheet. Search procedures by the end users follow a pattern and the drawings should be structured and titled to maximise this procedure. Recommended scales fore assembly drawings are: 1:50; 1:20; 1:10.
The drawings will comprise plan view and sections, and the thickness of lines will depend on the information hierarchy. Outlines and different components drawn with thicker lines alert the user to key information as the eye scans the entire drawing. The placing of the section on the drawing sheet should be carefully laid out to minimise search time for the end user.
The amount of text and dimensions included on the sheet should be just enough to achieve the purpose of the drawing. For example, a drawing of a substructure detail should not include text or specification relating to the roof. When placing text and dimensions onto the sheet, it is best to assist the end user by leaving the drawing area uncluttered. The focal point is the drawn detail. Once the diagram has been assimilated, further information is sought, with the eye radiating out form the focus diagram. The diagram should therefore be encircled with dimensions and text, and the text should be legible, concise and accurate.
Code references direct the user to further drawn information such as component drawings or to the bill of quantities. The specification or the measured section of the bill of quantities should explain the quality of the material or workmanship. This will avoid expensive duplication of specifications on the drawings, reducing the possibility of discrepancies between tender and contract documents.
This type of drawing shows individual components in the unfixed state. Information will include component sizes, tolerance and specification with reference to the bill of quantity.
- Wood window head detail
- Special door construction
- Coping stone
Component drawings are often large-scale, sometime full-sized drawings showing individual components. Assembly drawings will contain several components, showing how the individual components fit together to make a building element.