Lot Coverage: 14 Things (2024) You Should Know

If you’re considering a construction project for your house or land that violates the local jurisdiction’s zoning ordinances, then you’ll need to apply for a variance – and you’ll likely run into the term “lot coverage.”

In this blog, we’ll examine what lot coverage is, how it differs from other similar terms, and how it factors into obtaining a variance.

Let’s get started!

1. What is lot coverage?

Lot coverage is the percentage of the total lot area that is covered by impervious surface.

In other words, it is the size of the footprint of a building and/or structures on a lot divided by the size of the parcel.

It’s expressed as a decimal number.

The lot coverage is used to calculate the intensity of development proposed by a project.

In essence, it’s the total square footage of all structures covering a lot from a bird’s eye view.

2. What’s the formula for lot coverage?

Lot Coverage = (Building Footprint ÷ Lot Area) x 100

3. What terms should you know when calculating building and lot percentages?

As you read through this blog, you may come across some terms you aren’t familiar with.

Here are some terms you should know along with their definitions.

bulletBuilding coverage:

The percentage of the lot area that is covered by building area, which includes the total horizontal area when viewed in the plan.

bulletImpervious cover:

Any structure, surface, or improvement that reduces and/or prevents absorption of stormwater into soil.

Porous paving, paver blocks, gravel, crushed stone, crushed shell, elevated structures (including boardwalks), and other similar structures, surfaces, or improvements are considered impervious cover.

Grass, lawns, or other vegetation are not considered impervious cover.

bulletLot coverage:

The percentage of lot area that is covered by impervious cover.

bulletFloor area ratio:

The total building floor area divided by the gross lot area.

4. What’s an example of lot coverage?

A footprint of 1000 square feet on a 5000 square foot lot results in lot coverage of .20 or 20%.

1000 square feet / 5000 square feet = .20

5. What areas should be included when computing lot coverage?

When making this calculation, be sure to include the following areas:

bulletAll buildings, including single, two, or multi-family dwellings

bulletAll buildings of a nonconforming use

bulletAccessory structures, including sheds, garages, pools carports, decks, roof overhangs exceeding 20 inches, platform walkways, and similar structures

bulletWalkways and driveways

6. What areas should be excluded when computing lot coverage?

It depends on your local jurisdiction, but sometimes certain landscape features will be exempt. 

This is because zoning by-laws sometimes use the total of “all building footprints” to determine the 20 percent allowed lot coverage restrictions.

However, in other areas, wetland by-laws or more restrictive zoning codes will include the above-mentioned accessory structures and landscape elements in the 20 percent coverage.

7. What does a lot coverage checklist look like?

Here is an example of a lot coverage checklist:

A lot coverage worksheet is a requirement for many building permits and land use applications.

You should look for one of these worksheets at your local zoning office.

Include this worksheet and a scaled drawing showing the percent lot coverage in your application.

Your scale drawing should usually include:

bulletThe location and dimensions of all building footprints including, building foundations, overhangs, canopies, balconies, carports, parking lots, driveways, swimming pools, etc

bulletA table of all areas and their dimensions

bulletThe maximum coverage allowed for the zoning district in which the property is located

bulletThe lot area and source of the lot area information

bulletThe proposed maximum lot coverage as a percentage of lot area

8. What’s the difference between building floor area ratio (FAR) and building lot coverage?

A building floor area ratio (FAR) is the sum of all the floor space in a home divided by the lot area.

The building lot area is only the sum of the floor area that covers the ground floor or ground level of the lot.

Here’s a great graphic that may allow you to visualize each.

9. How is lot coverage calculated?

Below is an example of how lot coverage can be calculated:

10. What’s the difference between the floor area ratio and lot coverage?

The floor area ratio calculates the size of the total square footage of the building relative to the lot.

On the other hand, the lot coverage considers the size of only the footprints of buildings and structures.

The lot coverage ratio will also include structures like garages, swimming pools, sheds, and other nonconforming buildings.

11. What is an impervious surface?

Above, we talked a little bit about impervious surfaces (or impervious cover).

Impervious surfaces are created surfaces (i.e., brick, stone, concrete, asphalt, etc.) that are placed on land for decoration or to facilitate development or passage.

Examples of impervious surfaces include patios, swimming pools, sidewalks, buildings, tennis courts, driveways, retaining ways, etc.

Impervious surfaces are regulated because, when more land is covered with buildings and pavement, water runoff can cause drainage problems on your property and to neighboring properties.

12. What type of regulations exist for impervious surfaces?

Regulations establish setback requirements for all new impervious surfaces as well as the total amount of allowable impervious coverage.

The amount of overall coverage permitted is often based on the size of the residential lot.

Here is an example:

Lot SizeLot Coverage
30,000 square feet or greater25 percent
10,000 square feet to 29,999 square feet30 percent
Less than 10,000 square feet40 percent

13. When is a permit or variance required?

Please check with your local municipality or planning commission to verify when a permit is required.

For example, a permit may be required when new impervious surfaces are greater than 50 square feet in area.

Or if more than 50 square feet of impervious surface are added to a property over a three-year period without obtaining a permit.

In many areas, there is a permit fee that you should consider.

A variance is a complex process, so you should review it carefully whenever your project violates your local jurisdiction’s zoning ordinances.

In some cases, the variance can be so challenging that it’s better to reconsider your project instead of going through the application process.

If it’s possible to avoid the variance process, then that is recommended.

14. How do you apply for a permit or variance?

To apply for a permit, you’ll need a copy of your property survey.

This is necessary to review your application as all measurements are made from property lines, and all property lines are shown on the survey and indicate the actual property owned.

Note that sidewalks and curbing in the township right-of-way are not counted as part of the coverage calculation.

Once the permit is obtained, the homeowner must call for inspections after construction.

To apply for a variance, follow these steps:

bulletExamine your construction plans

Examining your construction plans can help you determine if there’s a way to do the project while avoiding the variance.

Initially, this may seem a bit absurd, but long-term, you’ll save yourself the hassle of applying for the variance.

Additionally, you’re unlikely to be approved for the variance if your plans can be easily changed to comply with voting laws, so it’s important to cover this step either way.

bulletFamiliarize yourself with the local jurisdiction’s variance requirements

A variance will generally be granted if it meets the following four criteria:

1) Compliance with the zoning laws would cause undue hardship on the landowner

2) The proposed construction is necessary for a reasonable use of the property

3) The proposed construction would not alter the essential character of the neighborhood

4) The proposed construction represents the least intrusive solution possible

bulletDetermine what type of variance you need

There are two basic types of variances: area and use.

Area variance: Required when the configuration of the lot dictates that the zoning regulations simply be relaxed.

Examples of an area variance – exceptions for minimum setbacks from the property line and minimum floor areas.

Use variance: Required when the building’s intended use will violate the zoning ordinances; much harder to get than area variances

Example of use variance – building an office building in a residential neighborhood.

bulletGet your lot surveyed

If you’re planning a new construction project, then you’ll need to have an updated survey done on your home.

This will keep you out of legal trouble and ensure that the construction project is being done on your land.

If you’re seeking a variance regarding minimum property setbacks, then this is especially important.

bulletPrepare architectural plans for the proposed project

Your municipality or county will likely require some sort of architectural plans for your project.

Check to see what level of detail they require.

Some may need the plans stamped by a licensed architect or engineer while others may allow you to create the plans with home remodeling software.

bulletFile your application for the variance

File your application at your local city or town hall.

You’ll need to submit your survey, architectural drawings, a written statement of intent, and a separate application if it’s required by your local jurisdiction.

bulletNotify all property owners within a small radius of the property of your proposed change

If your application is approved, you’ll need to notify your neighbors.

It’s likely that your local jurisdiction will specify the length of this “small radius.”

You may also need to go to a hearing before it’s approved.

Nearby property owners can attend and ask you questions, so be prepared to field these if this is relevant in your case.

Final Thoughts

If you’re considering renovating your house or developing a parcel of land, then lot coverage is a term you’ll quickly become familiar with.

Understanding the nuances behind these definitions will make the whole process of applying for a variance in your local municipality much smoother.

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Erika Gokce Capital

Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.


2 thoughts on “Lot Coverage: 14 Things (2024) You Should Know”

  1. Hi, i currently have been in talks with my town about the lot coverage % that i have and what it needs to be after having a deck put in. The building inspector is giving me a bit of a hard time but maybe im just not understanding it completely. I currently have a deck (20’x14′) but i need to have it replaced as it is falling apart. Since we are having this torn down figured why not upgrade it a little bit and add a roof onto half of my deck (10’x14′) and a patio directly underneath the deck. All 3 of these overlap each other but hes saying that the roof and the patio will not be approved due to my lot coverage %. so i guess my question here is should all 3 components be taken into consideration even though from a birds eye view it is only covering the 20’x14′ area?

    • Hello Timothy, the building inspector sounds pretty unreasonable to me, but I suppose his reasoning is that the deck is not covering the “green space” on the ground at the moment, while the patio would. It’s also possible that this jurisdiction calculates lot coverage based on the entire square footage of built-up area (not just the bird’s eye view area). I would recommend calling a few local contractors, architects or engineers and see if they’ve also had similar issues. Best of luck!


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