Site data, survey and setting out

What a design needs to start

Title and map data

Title deed and map extract: the exact boundaries of the plot, the encumbrances, the easements.

Topographic survey

The levels of the ground, existing objects, trees, retaining walls, the position of neighbouring buildings. This gives the datum for the design.

Without an accurate survey the ground connection, the level of the entrances and the drainage are all uncertain.

Utility data

Where the services are, with what capacity, on what conditions they can be connected. Utility connections.

Planning data

The relevant provisions of the local building code, any protected status. Local building code.

Ground investigation

Where warranted — and for the cost of the foundations that is nearly always. Ground investigation report.

For an existing building

Add a survey of the existing structure: geometry, structural system, condition, capacity. Surveying an existing building.

Why to start here

Feasibility is decided here

The plot may not allow what the client wants. Better to find that out in the first week.

The cost estimate rests on it

Foundations, earthworks, utility connections — large items, all dependent on the site data.

The design work is not wasted

A design produced without a survey often has to be started again once the real data is known.

The accuracy question

For a prefabricated structure the setting out and the vertical accuracy matter particularly, because manufactured members do not adapt. Setting out and foundation tolerances.

So the survey work does not end with the design: it is needed during construction too.

The point

Gathering data is the cheapest stage of the design and the one that reduces the most risk. Save on it and you pay in the construction.