Before setting up a new project in Revit you need to make some decisions about how it will be set up.
Correct setup is important in Revit as changes later on to some things are not possible, or can create havoc with the model.
ESTABLISH LEVELS
Work out what the Levels will be for the project, and what they will be called.
Is the level at ground called Ground Floor or Level 1?
Establish what the AHD level of ground floor is.
Are there lower or upper ground floors? Basements? Roofs?
Are levels finished levels or structural levels?
If roof falls where is roof level?
PROJECT BASE POINT
Establish a base point for the project. Ideally this should be an identifiable (and measurable) location on the site, and be related to how the new works will be set-out.
It also needs to be identifiable on surveys.
PROJECT SETOUT
Decide which building face or boundary will align with the sides of sheets (and your computer screen).
Pick something that will ensure most of the building can be modelled orthogonally.
Revit does not handle arbitrary angles well. If building to boundaries and those boundaries are not orthogonal establish setout lines that are rational angles to no more than 2 decimal places.
ORIENTATION & SHEET SIZE
Decide which way the project will appear on plans. Obviously the majority of walls should run up/down and left/right.
Base you decision on plans at 1:100, even if it means plans will be split over multiple sheets. (It is dangerous to rotate Revit projects after they are started, so make your decision on likely Documentation requirements, not sketch design requirements).
Keep in mind orientation may be effected by the sheet size chosen.
OBTAIN SURVEY & CONTEXT INFORMATION
A survey is not necessarily required to start modelling in Revit, but the sooner one is available the less likely re-modelling will be required.
Surveys are generally CAD files. Request the following information:
Survey is drawn to scale.
All entities are at Z value of zero, except for contours.
True North is identified within the survey (i.e. not on the sheet).
A point within the survey has eastings and northings identified. (e.g. a benchmark)
The survey CAD contains a 'triangle' mesh on its own layer (called a TIN - triangulated irregular network).
Alternatively the survey CAD contains contours on their own layer drawn at the Z value of their AHD height.
If possible request an existing conditions Revit model from the project surveyor. This not only reduces the amount of work and time your team will spending modelling, it places responsibility for accuracy and completeness on to the surveyor.
If this is be provided request their model:
be the same Revit version you will be using.
be orientated to the same project North you will be using.
use the same project base point you will be using.
have AHD northing and eastings set (via set coordinates at a point).
Of course you will have to provide this information to the surveyor.
WORK OUT (INITIAL) LINKED FILE STRUCTURE
Think about the best way to structure linked files.
Initially try and keep as much of the Revit model as possible in one file. Leave splitting the Revit model up until it is absolutely necessary.
For an best linked file practice refer to GUIDELINES > LINKED FILES > LINKED FILE STRUCTURE