Illinois Boundary Survey Practice and Conveyancing
This domain tests Illinois-specific procedure: which statute governs licensure and practice standards, when a plat is mandatory, how deeds and recording create priority, and what a boundary plat must show.
Statutory framework
The Illinois Professional Land Surveyor Act (225 ILCS 330) governs licensure, sealing, and discipline through IDFPR and the Illinois Board of Land Surveyors. Minimum practice standards appear in 68 Ill. Adm. Code 1270, covering record research, field procedure, monumentation, and plat content.
The Plat Act, 765 ILCS 205
Any division of land into two or more lots or blocks where any resulting lot is 5 acres or less must be platted and approved by the municipality or county before recording. Divisions in which every parcel exceeds 5 acres are exempt. Recording an unapproved division does not create a valid plat.
Deeds, descriptions, and recording
A deed needs parties, words of grant, a description sufficient to identify the land, the grantor's signature, and an acknowledgment for recording. Illinois is a race-notice state under 765 ILCS 5/30: a later purchaser prevails only by recording first while taking without notice - actual, constructive (record), or inquiry.
Plat content
Show the basis of bearings (record, assumed, or State Plane), all found and set monuments, record versus measured distances where they differ, adjoiners, easements, and encroachments.
Worked example
A client wants to split a 4.2-acre tract into two 2.1-acre lots. The Plat Act applies because at least one resulting parcel is 5 acres or less, so a plat must be prepared, approved, and recorded before the deeds are delivered. Conveying by metes-and-bounds deeds without an approved plat would violate the Act even though the two deeds together account for the whole tract.
Traps
An unrecorded deed is valid between the parties but vulnerable to a later purchaser without notice. Do not assume a statewide statute requires recording every boundary survey - subdivision plats are the recorded instrument and county practice varies. Never resolve an ambiguous deed by area alone.