Survey work is due to start on the playing fields at Nailsea Community School in North Somerset.
The Department for Education and Skills has allocated £28.9m to rebuild the secondary school on its current site by the end of 2009.
The existing school playing fields have been identified as the location for the new school.
The surveys - to be done in two phases - will determine the best position for the new building on this site.
Initially a geophysical survey will be carried out where the playing fields will be scanned to highlight any potential underground problems.
This will be followed by a geotechnical survey which will involve drilling boreholes and digging trenches to confirm the most suitable position for the new building.
The consultants will also be carrying out a geophysical survey of the Golden Valley site, which is owned by Nailsea School, with a view to using part of the area for temporary sports pitches while the new school is being built.