Revised January 2020

Record CAD Drawings

Access to existing drawings
The county council holds measured survey floor plan drawings of all its properties in AutoCAD format.
All drawings are logged into a Drawing Register showing date of request, date of completion, date of issue, parish, establishment number, establishment block number, floor level and Technician Initials plus a unique number made up of the EN, block number and floor level.
Drawing amendments are carried out by the Property and Facilities CAD/Survey Technician.
Amended drawings produced by consultants must be submitted to the Property and Facilities CAD/Survey Technician.
Supporting approved consultants will be allowed a copy of these drawings on request to Property and Facilities CAD/Survey Technician, contact Estates.Team@Oxfordshire.gov.uk
Drawings for new projects
All consultants are required to produce as built drawings for all schemes undertaken by them upon completion of projects. It is a requirement that all drawings shall be produced in AutoCAD dwg format. As part of this duty the consultant must carry out appropriate measurement checks at project completion handover stage to ensure the drawing accurately reflects what has been built. To ensure co-ordination of drawings the consultant must provide an indication of completion dates for capital and minor works schemes and inform council's CAD/Survey Technician when drawings will be available.
An extract of the scheme drawing is required showing floor plans as well as the REVIT/design drawings.
• Each room in a block floor plan should show room usage, floor coverings and sanitary fittings.
The council's CAD/Survey Technician will extract the floor plan elements from that drawing and place in the correct format.
Measured surveys of existing property
Where the consultant is commissioned to carry out surveys of existing property or new leasehold property, a separate commission will be placed. Drawings must be provided in the convention / format set out in Annexe1.
Annexe 1
AutoCAD drawing convention for block plans
The following guidelines are intended to provide some degree of consistency between block plan drawings. Some points relate only to starting a drawing but the majority should be applicable when amending drawings. In some instances, the format of an existing drawing may differ from what is now specified.
1.0 File structure and drawing format/content
1.1 The file name for each drawing is of the form:
(Establishment No)_(Block No)_(Floor Level).dwg
e.g. 0399_A_G.dwg
New drawings should contain all floors of an individual block with the file name ending in a 'G' for ground floor, as is consistent with recent surveys.
1.2 At present, all drawings should be saved in AutoCAD 2018 dwg format.
1.3 AutoCAD drawings are saved to the Consultant’s X: drive
2.0 Drawing standards
2.1 Drawings are drawn at a scale of 1:1mm in AutoCAD model space.
2.2 The drawing should be orientated sensibly so that a person unfamiliar with the site is able to locate themselves quickly. Orientation should ideally be consistent for all block drawings for a site. A north arrow should accurately show due north in relation to the block. Each floor should have its own north arrow.
2.3 Block plan detail should be drawn on the following layers to provide consistency between drawings:
B-WALLS (yellow) - for internal walls
B-WALLS_EXTERNAL (green) - for external walls
B-DOORS (red) - for all types of door
B-FLR_FINS (blue) - to show changes in floor finish (non-plottable)
B-FEATURES (blue) - for all other features including ramps, steps, covered areas, poles etc.
2.4 Walls meeting at apparent right-angles should be assumed to be perfectly perpendicular.
2.5 Doors should be shown extending perpendicular from the adjoining wall and with an arc showing the path of opening. Windows are not required.
2.6 The main entrance and all other entrances to a block from outside should be labelled.
2.7 Break lines should be used to show where stairs continue on the next floor and where walls run into an adjoining block.
2.8 The 'up' direction for stairs and ramps should be indicated.
2.9 The external wall outline of the ground floor should be shown on other floors, if the whole base floor area is not occupied. The external wall outline of adjoining blocks should also be shown and the block names indicated.
2.10 If the information is available (OS data or site measurements), a separate labelled block plan should be drawn showing all block positions for the establishment/site in relation to each other.
3.0 Setting up drawing layouts
3.1 An AutoCAD drawing layout must be produced for each individual floor of the block and titled accordingly (i.e. the ground floor layout should be named GROUND; first floor layout should be named FIRST etc.).
3.2 An appropriate sheet size should be chosen to fit the floor detail at a scale of 1:100 and a viewport created at this scale within the layout.
3.3 Each layout/floor should have an appropriate Oxfordshire County Council sheet from the AutoCAD Library (or the consultant's own sheet). The sheet text should be amended to suit the drawing i.e. enter the correct drawing number, establishment details, drawing date, survey date etc.
3.4 A smaller viewport should also be created in a corner of the layout to show the block plan for the establishment/site. This should be at a scale of 1:1250 or 1:2500 as appropriate.
4.0 Setting up drawings
4.1 Layers should be created as follows:
A400_ROOMAREAS (yellow)
A401_GEA (Green)
A401_GIA (Cyan)
4.2 On layer A401_GEA polylines should be drawn representing the Gross External Area (GEA) of each floor.
On layer A401_GIA polylines should be drawn representing the Gross Internal Area (GIA) of each floor.
These are accurately defined in RICS Property Measurement (Incorporating IPMS).
Oxfordshire County Council uses these definitions somewhat contentiously in that they often require that one building be defined as more than one block (e.g. a main building separated into A, A1 and A2 blocks based on age of construction). In this instance the GEA and GIA should be drawn as judged most suitable for each block, as no standards appear to exist for such a situation.
Composite plans are now produced, held and maintained to unite the sub-blocks and to include all blocks onto a single drawing creating a more complete view of an entire site.
A copy of the attributes required for the GEA is held in the AutoCAD library. The attributes are as follows and should be made visible:
An AutoCAD block must be created for the GEA of each floor. This must be on the A401_GEA layer and comprise of the GEA polyline and the attributes. The GIA does not need its own block. Attributes should be placed in a suitable position next to each floor drawing. The attribute values should be entered on creation of the block.
4.3 On layer A400_ROOMAREAS, polylines should be drawn to represent the floor area of each individual room. These lines should step halfway into doorways as consistent with past drawings. It should be noted that covered areas are classed as rooms although they may be open-sided.
A copy of the attributes required for each room is held in the AutoCAD Library. The room attributes are set up as follows:
These should be visible, and values must be entered:
ROOM_USE (must take the value of one of the standard room uses)
The following should be invisible but values must again be entered:
The following should be invisible, and values need not be entered but should be if the information is available:
SUB_BLOCK (leave blank as sub-blocks are not used by OCC)
An AutoCAD block must be created for each room (on the A400_ROOMAREAS layer) comprised of the polyline for the room and the room attributes. The AutoCAD block number must be the same as the room number attribute and be numbered in a logical order across the block. Attribute values are entered for each room as the blocks are created. All attributes must be used for each room even if their value is left blank.
5.0 Amending and archiving drawings
5.1 Superseded drawings will be placed in an 'archive' folder at the level where AutoCAD drawings are held in the directory structure.
5.2 Before an amendment is made to a drawing, a copy of the original should be placed in the archive directory. If more than one copy of the drawing exists in the archive folder then a date of archiving should be added to the file name. In this way a series of past drawing versions should be built up over time.
5.3 When a new version of a drawing is created, a brief summary of the changes made should be added to the amendment box of the corresponding AutoCAD layout, then initialled and dated.
5.4 If a block or drawing is no longer required as the block it relates to is no longer on site and has been archived from the database then the AutoCAD file is also put into the Archive folder.