Understanding the Importance of Plot Plans

If you’re considering an addition or external renovation to your home, be sure to account for the plot plan. Failing to do so could cause a significant delay in your project.


A plot plan, also known as a survey, is a drawing that shows the exact measurements of your property lines and all structures within. Usually kept on file with towns and cities, plot plans are used to track property and structures for tax and building purposes.


In recent years, many towns have added other requirements for plot plans, such as marking trees of a certain diameter and floor area ratio (the gross floor area of the home divided by lot size). These and other changes have made creating plot plans a more complicated and lengthy process.


Most towns require the completion of a plot plan before they’ll issue a permit for an addition or a porch or deck project. And work can’t begin until you have that permit in hand.


How long can it take for a plot plan to be issued? We recently saw one client wait for twoand- a-half months. It may not take as long for you. But to be safe, make sure you contact a surveyor sooner rather than later. After all, you don’t want the lack of a permit to hold up the construction process.


When is a plot plan needed?
If a renovation expands the three-dimensional footprint of a home and affects the open space on a lot, your local building department typically will want to verify their records. They may request an updated plot plan if they don’t have one on record for your property or the one they have on record appears inaccurate. Examples of when a plot plan is needed: additions, porches, roofing over porches, decks, dormers and bump-outs.


When might a plot plan be unnecessary?
If you’re replacing an existing structure (e.g. porch or deck) with something the same size, a plot plan might not be needed. However, the town will still verify the information they have on record — and might request a plot plan if the information appears inaccurate.

Who creates a plot plan?
A registered surveyor/engineer will complete measurements and produce a plot plan with their stamp on it. The cost generally ranges from $800 to $2,000.

What is a mortgage survey?
A mortgage survey is similar to a plot plan, but is typically less detailed and not considered official. Most people get a mortgage survey, which can be used as a reference tool, when they buy a house.

What is an as-built plot plan?
Sometimes required after a project, an as-built plot plan is used to confirm and update changes that were made to a property or structure.

Remember: Every town has its unique and sometimes obscure zoning bylaws and loopholes — and some towns are more difficult than others. If you have any questions about plot plans, please call us at 781-648-2835.