Surveying FAQ - Development Services

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Surveying FAQ

Who is the Ada County Surveyor?

Jerry L. Hastings, Ada County Surveyor
Idaho Professional Land Surveyor No. 5359

Why do I submit a final plat to the County Surveyor for Review?

Idaho Code requires that all subdivision plats must be verified by a second professional land surveyor. Idaho Code provides that the professional land surveyor making the survey certifies to the correctness of the plat. Idaho Code states that before the plat is recorded, a second, duly appointed Professional Land Surveyor must determine that the requirements of the platting law are met and certify such compliance on the plat. The Ada County Commissioners have appointed the Ada County Surveyor as the person to review plats to satisfy the state code requirement for verification of the plat by a professional land surveyor. This is only part of the total process in recording a final subdivision plat, however, the county surveyor review is the last, most comprehensive review before the plat is signed by the Treasurer and recorded. Almost all of the activities of the County Surveyor are regulated by Idaho State Code or are under the Rules of Professional Responsibility.

Where do I submit a subdivision plat for review by the County Surveyor?

The Ada County Surveyor’s Office is located in Ada County Development Services on the second floor of the Ada County Courthouse at 200 W. Front St. in downtown Boise.

What do I need to submit a subdivision plat or condominium plat for County Surveyor review?

Normally, the plat surveyor (the surveyor hired by the owner or developer to prepare and survey the plat) or their staff will submit the plat for review by the County Surveyor.

To submit a subdivision plat for review by the County Surveyor, bring either the original subdivision plat mylars OR one complete set of black line copies along with the appropriate fees, along with a Final Plat Review Application Form signed by the surveyor in responsible charge of the plat.  The Land Surveyor in responsible charge of the plat, the Owner(s), and the Ada County Highway District and Central District Health Department certificates must be on the plat and signed before it will be reviewed.

To submit a condominium plat for review, bring all of the items to submit for a subdivision plat as noted above, along with a copy of the condominium declaration signed and in a ready to record condition including all exhibits,  Condominium projects have a different fee structure than a subdivision plat.

The fee schedule can be found at the Ada County Surveyor Web Page at Surveying Fees and Forms

What are Mylars?

Technically, when referring to a subdivision or condominium plat, “mylars” is the plastic transparent material that the reproducible pages of the plat are made of. However, when referring to a plat it is common practice in the surveying community to call the sheets or pages of the plat, which will be recorded in the courthouse as mylars. We always require the original subdivision mylars be submitted to us, so there is only one set of documents to work with. This set will have all of the agency signatures on the plat. State code and our policy requires that these signatures be original and in black ink, including the Notary Stamp. The County Surveyor’s Office will review only, and work with, the original mylars and not blue line copies. Blue line copies could be revised by some other agency or individual and that change would not be reflected on the original mylars.

Which plats are submitted to the County Surveyor for Review?

The Ada County Surveyor only reviews “final” subdivision plat mylars for compliance with state code. The County Surveyor also reviews condominium plats, condominium amendments, amended plats, and plat copies for compliance with state code.

What does a condominium plat have to be reviewed by the County Surveyor?

Similar to a subdivision plat, a condominium plat and declaration is reviewed by the County Surveyor for compliance with state code.

The last section of the condominium act states: 55-1527. ZONING LAWS APPLIED WHERE NOT INCONSISTENT. Except where inconsistent with the provisions or purposes of this act, state and local laws relating to plats, recording, subdivisions or zoning shall apply to condominiums and to projects as herein defined. The County Surveyor will also review condominium amendments.

What's the difference between a condominium project and a subdivision plat?

A subdivision plat divides the land, provides a means for the sale of the land as well as for streets, easements, and utilities. The division of land is divided into and sold as lots.

A condominium project is a different kind of ownership. Generally, the project is composed of two entities, a unit and common area. The land is owned in common with the individual owning the air space in the unit. A condominium project consists of a declaration and a plat. Elevation views are shown to help visualize the vertical aspects of the units. We view the declaration as actually creating the project, and the plat as simply defining and describing the units to be sold.

How much does it cost to review a subdivision plat?

Fees to review a subdivision plat are based on the all of the costs involved in reviewing a plat. They consist of a base fee plus a fee for the number of total lots in the subdivision. The complete list of review fees can be found at the Ada County Surveyor Web Page at: Survey Fees & Forms

How much does it cost to review a condominium project?

Fees to review a condominium project are higher than those for a subdivision plat because of the additional time required to review the declaration and plat. Fees are based on the all of the costs involved in reviewing a plat and declaration. They consist of a base fee plus a fee for the number of total units in the condominium. The condominium fees can be found at the Ada County Surveyor Web Page at: Survey Fees & Forms

What's involved with the county Surveyor review of a subdivision plat?

Our current review process consists of many parts and we only review the original subdivision plat mylars, unless it is a Concurrent Plat Review.

1) There is an initial review or tech review done by an experienced survey technician. The tech review consists of running the mathematical closures of the boundary and all the lots. All items on the checklist are reviewed as well as ownership and the plat is scanned for field copies. Most of the technical issues with the plat are discovered at this level and a comment sheet is prepared addressing the issues and discrepancies.

2) At the next level of review, a professional land surveyor looks at the professional issues and aspects of the review such as a proper boundary survey, adequate controlling corners, correct ownership, and the findings of the field inspection. A final comment sheet is prepared for the plat surveyor to be sent back with the plat mylars for corrections.

3) Finally, the County Surveyor reviews all comment sheets before they are sent to the plat surveyor to correct.

4) Usually the County Surveyor’s staff inspects the monuments in the field, during this period of time, to see if they agree with the plat.

5) The plat surveyor sends the corrected plat back to the County to see that all issues have been addressed and satisfied. Along with the corrected plat, we require the voided mylars be returned. These are the previous version of mylars that we have checked from which we made the comment sheet. We then overlay the old version with the new version on a light table to see that corrections are made.

6) When all issues from the comment sheet have been addressed and field inspection is done, the County Surveyor will sign the plat. Some plats are County plats and will also require the Board of County Commissioners to sign the plat. The planner assigned to that project will coordinate and schedule for the Board’s signature.
Many kinds of issues can hold up a plat and some are processed more quickly than others. Plats that are prepared in the most professional manner and have few corrections speed up the process dramatically.

How long does it take to review a subdivision plat?

The County Surveyor’s policy is to start the plat review on a chronological basis, i.e. the order they are logged in to the front counter. All subdivision and condominium plats are unique and different. Because of this, they require different amounts of time to review and resolve all the issues. Each plat is reviewed by a survey technician and a professional land surveyor. A field inspection of the exterior boundary and lot corners is performed by the staff, on a random selection process. We have found that construction schedules can interfere with and delay the signing of the plat, and the County Surveyor’s office has no control over that period of time.

Usually, the backlog of plats dictates the time involved in getting started on a plat review. The larger the backlog of plats to review that more time it will take before a plat is started on. If there was no backlog of plats and we reviewed a plat with few issues, had a construction schedule that allows the surveyor to set the monuments and get them inspected, and had a plat surveyor with a quick turnaround time, we could theoretically start on a plat and have it signed in two weeks or less and be ready to record. Only occasionally do we have a small backlog. Because of the huge number of plats submitted in the last two fiscal years (16,800 lots) and the way plats are submitted to us (Cities sign plats and release them in groups, because of the city council meetings), we have averaged in the vicinity of 6 to 8 weeks from start to finish. Most of that time was due to the backlog and the construction schedule in the field.

How do I check on the review status of a subdivision plat?

The Ada County Surveyor’s homepage has a real-time link to a review log of the subdivision and condominium plats that have been submitted to the Ada County Surveyor for review which lists when the review is started and where it is in the process. The link is: Plat Review Tracking

What is a Comment Sheet?

A comment sheet is a list of comments and questions that are prepared from the review of the subdivision or condominium plat by the County Surveyor and the staff. It also includes the field inspection information.

When a professional land surveyor prepares a plat for review by another professional land surveyor from a government agency, the Rules of Professional Responsibility issued by the ISBPEPLS Board of Registration requires them to respond in writing directly to the plat surveyor and no one else until the issues are resolved. The comment sheet represents the official response to the surveyor, in writing, to satisfy that requirement. That is also the reason that other interested parties are not included in the review of the plat. The plat surveyor is in responsible charge of the plat and is the only one who can make the appropriate changes to the plat.

What are "Voided Mylars"?

“Voided Mylars” are the plat mylars that have already been reviewed as part of the County Surveyor verification of the plat. They were sent to the plat surveyor for corrections and are coming back to the County Surveyor’s Office as being superseded by the corrected mylars. Voided mylars are always returned with the corrected new mylars and marked “Void”. They are used to overlay the new mylars to see what changes have been made and for verification of those changes. They represent the initial review and completely new fee will be charged if they are not returned with the corrected mylars. Under certain circumstances, there can be several sets of voided mylars. The county will periodically shred these documents.

What does the County Surveyor do?

The County Surveyor works at the pleasure of the Director of Development Services and the Board of Ada County Commissioners performing surveying duties for Ada County. The County Surveyor is in charge of supervising the Survey Division. Part of those important duties are the review of subdivision and condominium plats for compliance with state code. Almost all of the activities of the County Surveyor are regulated by Idaho State Code and not by county code.

What is an amended subdivision plat and how do I submit it?

An amended subdivision plat is filed to correct or change the previously recorded plat. An amended plat can be filed to change lot lines, to change errors not practicable to do with an affidavit and to correct ownership. Those items considered “scriveners errors” by the surveyor would be covered with the filing of an affidavit of correction. The Idaho Code does not provide any guidelines for amended plats.

Our current County Surveyor policy for amended plats that are correcting ownership, is to submit the plat to the County Surveyor with all the appropriate signatures, and we will review it by overlaying the previously recorded plat. Normally we are only looking for the word “amended” to be added to the front of the subdivision name throughout the plat and a statement on the front sheet explaining why the plat is being amended. This process does not involve being logged into the regular subdivision review list and presently there is no fee being charged. This is to encourage the surveyor to file the amended plat

What is an amended condominium plat and how do I submit it?

A condominium amendment is where an existing approved condominium project has been recorded and one or more of the units are divided or changed. The County Surveyor has a specific process for reviewing and recording a condominium amendment. In most cases, the declaration from the original condominium project spells out the process to follow, which is usually according to the county surveyor’s amendment procedure. This procedure is outlined on the website and may involve filing a new declaration as well as the amendment plat.

Why does the County check survey monuments in the field?

As part of the verification of the plat, all monuments shown on a subdivision will be checked in the field for agreement with the plat. This inspection complies with the code requirement that all the requirements of the code herein are met. The pin inspections are done on a random selection process on approximately 10% of all plats submitted.

How do I apply for a "County" subdivision plat?

Application for a “county subdivision”, where Ada County has jurisdiction, is done through Ada County Development Services, on the second floor, in the Ada County Courthouse on 200 W. Front Street, Boise, Idaho. There is a final subdivision plat application that is submitted to the front desk with the appropriate fees and accompanying documents. This is completely different and in addition to, the final plat review done by the County Surveyor. A staff planner will be assigned to the subdivision to guide the owner through the process. See the Development Services Planning and Zoning webpage for forms.
To aide in the planning process, the County Surveyor reviews preliminary county plats as part of the completeness review for the surveying aspects of the plat. All preliminary plats must have the boundary resolved at the preliminary plat level. Because of the Blaha Supreme Court Case, only the preliminary plat is appealable, therefore the preliminary plat must meet conditions of a final plat. To the plat surveyor this means that the preliminary plat must show a complete boundary survey, with a legend, all controlling corners, and be stamped by the plat surveyor.

What's the difference between an engineer and a surveyor?

In reference to a subdivision plat, an engineer works on the design part of the subdivision and those areas involving drainage, water and sewer issues. The surveyor is responsible for preparing, surveying and signing the plat. They survey and set the monuments in the field. The surveyor’s Rules of Professional Responsibility put them in responsible charge of all aspects of the subdivision plat.

Licensing of professional land surveyors is regulated by the Idaho Board of Professional Engineers and Professional Land Surveyors.

Can an engineer perform a subdivision plat?

No. Only a professional land surveyor can prepare, sign a subdivision plat and perform the survey.

I don't know who the plat surveyor is for my plat, why is that important?

It is important because only a professional land surveyor can prepare and sign a subdivision/condominium plat. That is the only person who can make changes to the plat. The staff of the Survey Division are required to deal with the surveyor who stamps the plat and only with that surveyor. Therefore, to keep abreast of the progress of a plat through the review process, it is important to communicate with and know who the plat surveyor is.

How do I reserve a subdivision or condominium name?

To prevent duplication of existing recorded or reserved names, the Ada County Surveyor will approve and reserve a subdivision name or a condominium name for a new project. The procedure and rules for naming subdivisions are found on the Ada County Surveyor website on the left side, under “Reserved Sub Names”

Choose a unique name not found in the database list in accordance with the guidelines on the web page. Names are reserved by e-mailing the County Survey Staff at  This provides documentation for the applicant and for our files. We can honor these reservations only as long as the  projects are in the approval process.  Final approval can only take place when the final plat is recorded.

Who is on the staff that will review my plat?

Currently, all of the staff related to the review of a subdivision plat is located in the Survey Division of Development Services, on the second floor of the Ada County Courthouse. The Survey Division staff consists of three survey technicians and two Professional Land Surveyors.  The County Surveyor is Jerry Hastings, PLS Idaho. Staff contact information is shown on the Development Services homepage or call  (208) 287-7900 for more information.

Who do I contact when mistakes are found on the County Surveyor's webpage?

The Ada County Surveyor’s home page contains a wealth of information on preparing and tracking subdivision plats, survey control information for Ada County, and updates for the survey Corner Records (CP&F’s). The County Surveyor is also responsible for the approval and reservation of subdivision names. The list and procedures are found on the website.

There are bound to be some mistakes and mistaken information with the vast amount of information available on the website. Feel free to call the Ada County Surveyor to correct any discrepancies you find at (208) 287-7900.