Surveying a building or site

zulutango

Although not formally trained, I'm fairly proficient at AutoCAD and I'm hoping to start a course soon in Revit Architecture. As a project I'd like to draw up a farmhouse that belongs to a relative of mine.

I'm a novice at surveying sites (i.e. fairly clueless!), but I was thinking there must be a tool that I can use on site to determine x,y,z co-ordinates of certain points, before going back home and starting to draw it all up? I could go to site and pick a point and measure everything from that with a measuring tape, but it seems quite laborious and probably would be inaccurate anyway.

Any help appreciated!

ftlnn

Yep there is..

If your not too bothered about accuracy, get a map extract of the area, google maps etc. in an image format, save the image and scale it up based on a known dimension, begin to trace...

Supertech

zulutango wrote: »

I could go to site and pick a point and measure everything from that with a measuring tape

That's exactly what surveying is !

A total station or laser scanner is the only tool that will give you all of the information you mention, but both will have costs attached.

If you want to model the farmhouse, the only real way to gather the data is to go and measure it. OSI Mapping or Google will allow you to draw the site roughly but not the buildings. There is no accurate free tool to give you exact x, y and z coordinates, and if you can't get accurate basic points, then any thing else is worthless.

If your using a tape, take plenty of diagonal measurements to relate buildings to one another and to the site boundaries.

zulutango

Thanks for the responses. You say there's no accurate free tool, but is there one I can rent or buy? Surely, some genius must have come up with a handheld device that directs a laser at a point and gives an x,y,z co-ordinate on a readout, and then allows you to upload hundreds of them to a pc. I should patent this idea!

Supertech

zulutango wrote: »

Surely, some genius must have come up with a handheld device that directs a laser at a point and gives an x,y,z co-ordinate on a readout, and then allows you to upload hundreds of them to a pc. I should patent this idea!

That's a total station. There isn't a hand held one which will give you all three coordinates, as you need to be working from a fixed point.

Leica produce a tool called a Disto which has software available which allows you to measure and upload to a PC, but it won't give you accurate Z coordinates. They cost a couple of hundred Euro to buy, and the software is extra.

A total station sets up on a tripod over a fixed point and fires a laser to give you xyz coordinates of various points relative to that point. It's one shot at a time, and so can be a bit tedious if measuring a building.

A laser scanner works on the same principle, except it fires 100's of 1000's of laser shots per second, and is therefore more practical in terms of measurement of buildings or other features which require more data to describe them.

What you could do is hire a total station and measure basic control points on site and fill in the rest of the detail later.