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How Much Does It Cost to Install a Septic Tank System?

Average range: $3,100 - $9,600
Low
$1,500
Average Cost
$6,100
High
$20,000
(standard 3-bedroom system with a 1,000-gallon tank)

Get free estimates from septic tank specialists near you
Here's what happens next

How Much Does It Cost to Install a Septic Tank System?

Average range: $3,100 - $9,600
Low
$1,500
Average Cost
$6,100
High
$20,000
(standard 3-bedroom system with a 1,000-gallon tank)

Get free estimates from septic tank specialists near you
Here's what happens next
Step 1
Answer a few questions
Tell us what you are looking for.
Step 2
Find out how much your project will cost
The contractors will offer competitive free quotes for your job.
Step 3
Compare the quotes and hire
Compare the estimates and hire the contractor who best fits your needs.

Having a septic tank is a great wastewater solution if your home is not hooked up to the municipal wastewater system. When installing a septic tank system, it is important to ensure it is high-quality to prevent leaking or contamination of your yard and high maintenance costs. There may be local rules or regulations in place regarding septic tanks, so be sure to check with your local municipality before purchasing a septic system.

The average septic tank installation cost is $3,100 to $9,600. Most homeowners pay around $6,100 to install a standard system with a 1,000-gallon tank, typically suitable for a 3-bedroom household. Prices vary depending on the tank size and materials used. A small system for a 3-bedroom house using a plastic tank will likely cost closer to $1,500. Expect a larger system for a 4 or 5-bedroom house constructed of concrete or fiberglass to cost around $20,000.

Septic Tank Installation Cost

Average Cost of Septic Tank
National average cost$6,100
Average range$3,100-$9,600
Minimum cost$1,500
Maximum cost$20,000


Updated: What's new?

Septic Tank System Cost by Project Range

Low
$1,500
Small system using a plastic tank
Average Cost
$6,100
Standard 3-bedroom system with a 1,000-gallon tank
High
$20,000
Larger system for a 4 or 5-bedroom house constructed of concrete or fiberglass

New Septic System Cost by Type

There are many different types of septic systems, and each has pros, cons, and costs. Costs for septic tank systems depend on various things, including the lot size, soil type, house size, and weather conditions. The costs below do not include installation:


Average Cost of Septic Tank

Average Cost of Septic Tank


Type of Septic SystemCost (Material Only)
Gravity$1,500 - $4,000
Conventional$2,000 - $5,000
Anaerobic$2,000 - $5,000
Chamber$2,000 - $5,000
Drip Distribution$4,000 - $10,000
Pressure Distribution$5,000 - $7,000
Recirculating Sand Filter$6,000 - $10,000
Constructed Wetland$6,000 - $10,000
Community$9,200 - $15,700*
Evapotranspiration$10,000 - $15,000
Mound$10,000 - $20,000
Aerobic$10,000 - $20,000


* additional costs per connection.

Gravity Septic System Cost

Gravity septic systems are very simple in that they use gravity for water flow and filtration. A gravity system 1 does not need a pump. The tank in a gravity septic system is very important. It should have risers-to-grade to help with maintenance and an effluent filter that filters out larger particles before the water leaves the tank. This system requires at least a gentle slope so that the water flows properly without a pump 2. The average cost for a gravity septic system is $1,500 to $4,000.

Conventional Septic System Cost

A conventional septic system is typically used at single-family homes or small businesses. It is an older design but one that works well. This septic system includes a septic tank and then a trench that acts as a drain field. Typically in this system, the trench is constructed of gravel or stone. A geofabric is installed on top of the trench to allow water to enter the stone and prevent any sand or dirt from entering the clean soil. One downside to a conventional septic system is that the gravel and stone trenches take up a lot of space and might not work on a small lot. The average cost for a conventional septic system is between $2,000 and $5,000.

Anaerobic Septic System Cost

An anaerobic septic system is a very common option for homeowners. It is a fairly simple system that does not need additional chemicals or power. An anaerobic system uses bacteria that do not require oxygen to live to eat solid waste. The liquid waste is then piped out and distributed under the soil. As the water runs through the soil, the waste is naturally filtered out. An anaerobic septic system costs from $2,000 and $5,000.

Chamber Septic System Cost

A chamber septic system uses gravelless drain fields, and this system has surged in popularity over the past few decades. Some benefits to a gravelless drain field 3 include having a smaller carbon footprint 4, and they are easier to construct and install. They are also beneficial when there is not a consistent flow of wastewater, such as for a cabin or seasonal residence. Expect to pay between $2,000 to $5,000 for these systems.

Drip Distribution Septic System Cost

A drip distribution septic system is dynamic and does not require a large mound of soil. This system, consisting of drip laterals or long lengths of tubing, is installed between 6 and 12 inches underneath the soil. Using a pump, a large dose tank distributes the water in timed deliveries. This system requires a fairly large area and needs power to operate. A typical system costs between $4,000 and $10,000 but can be much higher, depending on how advanced the technology is. For example, if you add an electrical component, it will increase expenses.

Pressure Distribution Septic System

Pressure distribution septic systems only need 2 feet of distance between the bottom of the system and the water table level. This is a huge advantage for people who live in areas with high water tables. This system includes a pump chamber that pushes the water out and distributes it evenly across a distribution area. The pump can also push water uphill. As a result, there must be good control over the pump’s on/off action. These systems are slightly more expensive than a gravity septic system, but they overcome many barriers a gravity system cannot. The average cost for a pressure distribution system is between $5,000 and $7,000.

Recirculating Sand Filter Septic System Cost

What makes this septic system unique is the sand 5 filter portion of it can be installed above or below ground. Liquid waste, also called effluent water, is pumped into the top of the sand filter, which is typically constructed of concrete or PVC. The waste in the water is filtered out through sand and stone layers before entering the ground. This system is ideal for lots that have a high water table or for areas near surface water, such as a lake or river. Expect costs for a recirculating sand filter septic system to range from $6,000 to $10,000.

Constructed Wetland Septic System

This is a unique and interesting system that resembles a wetland. The effluent goes from the septic tank into what is called a wetland cell. Wetland cells are typically constructed of a liner 6, gravel, sand, and wetland plants. The plants must be chosen carefully because they will always be wet. The water flows into the wetland cell, and the plants, sand, and gravel filter out the waste. The water is then distributed into a drain field. This system can use gravity or a pump. The average cost for a constructed wetland septic system is $6,000 to $10,000.

Community Septic System Cost

Sometimes called a cluster system, a community septic system is decentralized, meaning it does not just serve one household. Typically, a community system serves at least two buildings. These are fairly common in rural subdivisions where there is a lot of space. These systems can be cost-effective and very efficient. The cost for a community system varies significantly because it depends on the type of system installed and the number of buildings or homes that are to be included in the system. An average cost for a conventional septic system for a community is between $9,200 and $15,700. Then, there is an additional cost per home or connection added to the system, which typically ranges from $3,400 to $5,100 per added connection.

Evapotranspiration Septic System

This unique system has an interesting design, where water is put into an open-air tank, and the water evaporates. The tank is lined with a durable water-tight material so that no water leaks into the soil. With this system, the water does not enter the soil at all. Evapotranspiration systems need to be installed in the right climate. It must be hot, have a lot of sun, and be in an arid climate. If there is too much rain or snow, the system can fail. The cost is usually $10,000 to $15,000.

Mound Septic System Cost

Mound septic systems are a unique design intended when the depth of the soil or bedrock is shallow, or the groundwater is high. They have a sand mound constructed in the area of the septic system. A pump pushes wastewater from the septic tank into the mound in doses. Then, the sand filters out the water before it enters the soil and groundwater. This design needs a lot of space to build. For a standard 3-bedroom home, the mound will likely be 200 feet long. For larger homes, an additional 30 feet of length is added per bedroom. It takes up a lot of space, but it is a beneficial system if you have shallow bedrock or high groundwater. The cost of a mound septic system ranges from $10,000 to $20,000.

Aerobic Septic System Cost

An aerobic septic system is also a popular system among homeowners. It utilizes bacteria that need oxygen to survive to eat solid waste. Due to this, the system pumps oxygen into the tank to activate the bacteria. These systems are more expensive to install and maintain but work well where other systems might struggle. These systems work on small lots, in areas where the soil conditions are not conducive to other septic systems, and where the groundwater table is too high to utilize other septic systems. It is also a good option if your home is located near a body of water. The average cost for an aerobic septic system is between $10,000 and $20,000.


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Septic Tank Cost by Material

There are several different materials for septic tanks. Each material has benefits, and some are more appropriate for different soil types, climates, or uses. They all do the same job, but there is a cost difference between them. The costs below are for a 1,000-gallon tank, which typically serves a standard 3-bedroom home:


Septic Tank Cost

Septic Tank Cost


Tank MaterialCosts (Material Only)
Concrete$800 - $1,250
Plastic$830 - $1,400
Fiberglass$1,600 - $2,000


Concrete Septic Tank Cost

Concrete septic tanks are very popular and the most common material used for septic tanks. They are durable and have a long life when made of high-quality materials and are constructed well. A good concrete septic tank can have a life of over 20 years. A concrete tank is very heavy, so big equipment is needed for installation. Other price factors can impact the cost, depending on if it is precast or reinforced with rebar 7. The average cost for a 1,000-gallon concrete septic tank is $800 - $1,250.

Plastic Septic Tank Cost

Plastic septic tanks are more durable than you might think. They do not typically crack, but they can break if soil conditions change or shift. Plastic septic tanks are much lighter than their concrete counterparts and are typically less expensive to install. While the cost of the tank is similar, the installation costs vary greatly between a plastic septic tank and other heavier materials. The typical cost of a plastic septic tank is between $830 and $1,400.

Fiberglass Septic Tank Cost

Fiberglass has many unique benefits. It is not a porous material, so there is very little chance algae will grow on the tank. It also is very sturdy and does not deteriorate underground. Like plastic septic tanks, fiberglass septic tanks are lighter than concrete or steel, so they are cheaper to install. There is also no chance of fiberglass 8 cracking, which could happen to concrete. The typical cost for a 1,000-gallon septic tank is $1,600 - $2,000.

Septic Tank Price by Size

The septic tank size you need varies significantly, depending on the home or building size you are servicing and the amount of waste produced. The most common way to break down the tank volume needed is by the number of bedrooms in the home. Historically, this is a good indication of the tank size needed. These prices are based on a concrete tank, which is the most popular material for septic tanks.


Septic Tank Price Chart

Septic Tank Price Chart


Tank SizeCosts (Material Only)
2-Bedroom House$720 - $1,200
3-Bedroom House$800 - $1,250
4-Bedroom House$1,200 - $1,600


Cost of Septic System for 2 Bedroom House

A septic system for a 2-bedroom house requires a minimum of a 750-gallon septic tank. However, it is important to check local regulations because many municipalities require a minimum of a 1,000-gallon tank for a septic system. The cost of a 750-gallon septic tank typically ranges between $720 and $1,200.

Cost of Septic System for a 3 Bedroom House

The minimum size of the tank recommended for a 3-bedroom house is a 1,000-gallon tank. Additionally, many local or state governments require a minimum of a 1,000-gallon tank for a septic system. A 1,000-gallon tank typically handles 360 gallons of water per day. If you want to calculate your water usage, estimate your water flow, and multiply it by 1.5. The average cost for a 1,000-gallon septic tank is $800 to $1,250.

Cost of Septic System for a 4 Bedroom House

A 4-bedroom house needs a slightly larger tank. A 1,250-gallon tank is the minimum tank volume for a home of this size. This tank handles about 480 to 600 gallons per day of effluent. Typically, 1,250-gallon tanks cost between $1,200 and $1,600. The cost varies significantly, depending on the tank material. Use the calculation above to estimate the water volume leaving your house.

Septic Drain Field Cost

There are five main types of drain fields 3 for septic systems. After water flows through the septic tank, it is distributed into a drain field. Drain fields distribute the water underground so that the soil can continue to filter it before it reaches the groundwater. Each has benefits and is appropriate in different situations and environments. Installing or replacing a drain field is typically the most expensive piece of a septic system. Below are the costs of each type of drain field.


Septic Drain Field Cost

Septic Drain Field Cost


Type of Drain FieldAverage Cost (Material Only)
Chamber System$3,500 - $10,000
Conventional Drain Field$5,000 - $20,000
Mound System$10,000 - $20,000


Chamber Septic System Cost

A chamber septic system is similar to a leach field 3, but it utilizes plastic chambers that are open on the bottom. There are typically multiple chambers across the drain field connected to the septic tank by pipes. Chamber septic systems work well in areas with good, natural soil that will easily absorb the effluent. The average cost for a chamber system ranges from $3,500 to $10,000.

Conventional Drain Field Cost

A conventional drain field is one of the more common drain field options. With this design, septic water is piped to an underground trench. The trench is typically quite shallow, ranging from 18 to 30 inches, and constructed of stone or gravel. The typical cost for a conventional drain system is between $5,000 and $20,000.

Mound System Cost

A mound system, also called an elevated seepage bed system, is unique compared to the other drain field options. This is a mound made of gravel and sand that is built up. It is meant for areas that have a very high water table or bedrock. Because materials need to be brought in and the mound typically needs to be significant 200 feet or more, costs are high. Expect to pay between $10,000 and $20,000 for a mound system.


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Sewer Pipe Cost

Sewer pipes 9 in septic systems are slightly different than the typical sewer pipe. They are a different size and usually are a minimum of 4 inches in diameter. These pipes have protection around them, such as baffles or sanitary tees that are typically constructed of concrete, fiberglass, or plastic and need to be acid-resistant. The most common materials for sewer pipes for septic systems are PVC and cast iron. The cost is dependent on the pipe length and location. The material cost of the pipe is between $100 and $240 per linear foot 10 of material to replace or install a septic sewer pipe. The cost for a plumber to do the installation or repair is typically between $45 and $200 per hour.

Septic Distribution Box Cost

While the distribution box might not seem like a major component in the entire septic system, it is one of the most important pieces. The distribution box is where the effluent flows through to get to the drain field 3. It is the connector between the septic tank and the drain field. If the distribution box is damaged or not functioning, it can cause the entire system to fail.

A distribution box is not very expensive, usually between $50 and $100 for a plastic distribution box. Concrete is more expensive because they are heavier and have to be precast or cast in place. The cost of a concrete distribution box is usually between $600 and $650.

Septic System Installation Cost

Installing a septic system can be a lot of work, depending on the system type. While it may be tempting to do it yourself, installing a septic system is an extremely technical project that should be carried out by a professional contractor. Not only do all connections need to be made perfectly to ensure the system does not leak, but the grade 11 and depth of the components are also very precise. From the outlet of the house until the water is out of the system, many steps need to work perfectly to prevent the failure of the system.

Hiring a contractor for the project should range between $1,500 and $4,000. This would include the system design, filing permits, and excavating and installing the system. For a contractor to do the design, it usually costs between $600 and $800. An hourly rate for a contractor varies based on the location, costing between $150 and $200 per hour. While the total project cost changes based on the septic system type, the hourly rate is pretty standard and should not change. A typical septic installation job should take about 2-5 days or 16-40 hours.

A permit is typically an additional cost and depends on your municipality and area, but they are usually not more than $1,000. Soil testing 12 and an inspection may also be needed. Inspections are normally free.

The installation of a septic system has several phases. First, the contractor completes an inspection to determine the scope of the design and if any soil tests are needed. The contractor then designs the system and applies for the permits. After this, excavation occurs, which is a very precise part of the installation process. Next, it is time for the system installation. The excavation and installation usually take between 2-5 days to complete. Once the installation is done, an inspector needs to approve it before filling in the soil and finishing the project.

Septic System Replacement Cost

Sometimes, pieces of a septic system may fail or get old and not work efficiently. This is normal. If your system needs maintenance, it will likely be significantly cheaper than installing a new system. For example, design and excavation are already done. Additionally, most systems have fairly independent pieces, so if a tank lid is cracked, simply replace the lid.

Some smaller pieces that might need replacement are the tank baffle ($23-$44), tank lid ($30-$65), and tank filter ($230-$280). If the tank pump fails, this is a bigger expense, typically between $500 and $1,200.

Two aspects of the system that are expensive to replace are the drain field, costing between $3,500 and $11,000, and the tank itself. A 1,000-gallon concrete septic tank could cost $800 to $1,250. A tank could fail if there are cracks, leaks, or damage.

Hiring a plumber or specialist for the replacement is usually between $45 and $200 per hour. The hourly rate may vary based on area, but it should be fairly consistent for any type of septic installation or repair.


Septic tank in yard


Septic Tank Riser Installation Cost

A septic tank riser is a pipe installed on the top of a septic tank to give you access to the tank at ground level. This makes your septic system more accessible and makes maintenance and repairs cheaper, faster, and easier. While it costs about $300 to $400, it can end up saving money in the long run by creating an access point to your septic tank that is at grade.

Cost to Install a Septic System for Mobile Homes

Mobile homes connect to septic systems the same way as any other building or home. The major difference when designing, installing, or connecting a septic system to a mobile home is that the placement is critical. A septic tank cannot withstand the weight of the home if you move it. As a result, the tank and septic system need to be in a location where the home will not be hauled over it.

The most common septic system type used for mobile homes is a conventional septic system with a standard drain field. The average cost to install and connect a septic system like this to a mobile home is typically between $3,000 and $5,000.

Septic Tank Maintenance Cost

Septic tank maintenance is a necessary and preventive aspect of having a septic system. Like most systems in your home, some maintenance is necessary to keep everything in the proper working order. In the case of septic systems, most maintenance is considered preventative. The most important maintenance task to complete is pumping and cleaning the septic tank every 3-5 years. This is a pretty standard timeline, no matter which system you have. The labor cost usually ranges from $295 to $610 and includes any tools and equipment the plumber or specialist may need. Most maintenance does not need any material replacements, so you will only pay if something needs replacing.


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Enhancement and Improvement Costs

Preparing the Land for your Septic System

It may be necessary to clear some land and do preparation work on the site before installing a septic system. This could include anything from soil testing to excavating the area for the drain field. Most contractors include this in their price to install the septic system because the elevation, slope, and system depth are all extremely specific.

Pump Alarm Cost

A pump 2 alarm may be necessary with some systems, such as a pressure distribution system. These alarms are triggered when the wastewater level gets extremely low. If the pump continues to run when there is no water to distribute, it can ruin the pump. A septic tank alarm ranges from $100 to $500.

Additional Considerations and Costs

  • Like all major home projects, the installation (or replacement) of a septic system should involve getting several bids from qualified professionals. It is important to get references and proof of insurance for your project. The work and materials should also have a guarantee or warranty. Often an installer can provide a maintenance agreement to inspect it annually and pump it every 1-3 years.
  • A permit is typically an additional cost and depends on your municipality and area, but they are typically not more than $1,000. Your site may need soil testing 12 as a part of the design and permitting process. These can range from very small to quite large in scope and depend on the property size, history, and location. If soil testing is required, you may need to hire an additional professional to perform the testing. After the system construction, an inspection occurs, but this does not usually involve a fee.
  • When using a septic system, be careful about what you flush down the toilet. For example, chemicals could harm or kill the bacteria in the septic tank and cause the system to fail. Some common household items can clog, back-up, and possibly damage the system as well. This is not only an inconvenience but could also cause an expensive repair. Some items include paper towels, diapers, cigarette butts, tampons, cat litter, and any fats, oils, and grease from cooking or other household activities.
  • Because of their roots, shrubs and trees may harm the system when planted near the tank or the drain field. It is important to have some plant growth over the drain field to prevent erosion. Grasses and shallow-rooted perennials are a great option to landscape over the drain field. Large trees and trees with aggressive roots, such as elm, birch, maple, ash, weeping willow, aspen, and beech trees, can ruin the pipes of the drain field, which can cost a lot of money to repair.

FAQs

  • How much does it cost to put in a new septic system?

The average cost to install a septic system is between $3,100 and $9,600, including both the system and installation. Anaerobic, gravity, and chamber systems are on the lower end of that average, usually costing between $1,500 to $5,000. More expensive systems include the mound system, aerobic, and evapotranspiration and range anywhere from $10,000 to $20,000.

  • How much does it cost to replace a 1,000-gallon septic tank?

A 1,000-gallon septic tank usually costs between $800 and $2,000, but the price varies depending on the tank material. A concrete septic tank has the cheapest material cost, between $800 and $1,250, but it is the most expensive to transport and install because of its weight. A plastic septic tank is slightly more expensive, $830 to $1,400, but its weight makes it much cheaper to install, and heavy machinery is usually not needed. A fiberglass 8 tank usually ranges between $1,600 and $2,000.

  • How many years does a septic system last?

A septic system typically lasts between 15 and 40 years. This is usually determined by the quality of the tank and the drain field 3. A concrete tank is extremely durable and, when constructed well, is fairly indestructible and can easily last 40 years. The lifespan of a plastic tank is about 30 years. The drain field can also be a limiting factor on the age of the system. The drain field type does not really affect the lifespan of the system. However, the quality of the soil and drainage is a huge factor. Not doing maintenance on the system is one way to shorten the life of any septic system.

  • How many acres do you need for a septic system?

The smallest area a septic system will usually fit in is a ½-acre lot. Most homeowners with small lots opt to use an aerobic septic system. Most systems, such as an anaerobic or chamber septic system, typically need at least a 1-acre lot. Mound systems need the most space because the mound itself is usually a minimum of 200 feet long.

  • Can heavy rain cause septic problems?

Heavy rain can cause septic problems for all types of septic systems because they can flood the drain field. If the drainfield floods or the soil is saturated, the effluent septic water cannot effectively drain into the soil. This can cause major backups in the tank and even flooding.

  • How many loads of laundry a day are safe to do with a septic tank?

A small septic system for a two or three-bedroom home can handle about 5 loads of laundry per day. This does not include any other water being used and is based on using an old washer with a 1,000-gallon tank. The washer type is a major factor because older washers can use up to 40 gallons per wash. New energy-efficient washers usually use 12 to 15 gallons of water.

Remodeling Terms Cheat Sheet

Definitions in laymen's terms, cost considerations, pictures and things you need to know.
See full cheat sheet.
glossary term picture Gravity System 1 Gravity system: A septic tank system that uses gravity to make the wastewater flowing out of the tank run downhill through pipes to the drain field or collection network
glossary term picture Pump 2 Pump: A device used to move air, liquid, or gas by mechanical means
3 Leach field: (Also known as Drain field) The part of a septic system that is used to remove pollutants and impurities from the fluid coming out of the septic tank.
glossary term picture Footprint 4 Footprint: The entire area of ground covered by a building, including the exterior walls and porch or patio areas
glossary term picture Sanding 5 Sand: Process of removing the top surface of a material, such as wood, using sandpaper and/or a specialized sanding machine (for large surface areas)
glossary term picture Liner 6 Liner: A covering, usually made of vinyl, for the walls and floor of a swimming pool, used to keep the water in and protect the pool's surface.
glossary term picture Rebar 7 Rebar: A mesh or bar made of alloy, used in construction projects to reinforce concrete
glossary term picture Fiberglass 8 Fiberglass: Plastic that is reinforced with glass fibers. The fibers may be mixed randomly throughout the plastic, or come in the form of a flat sheet, or be woven into a fabric
glossary term picture Sewer Line 9 Sewer pipes: Principal pipe in a sewage system
glossary term picture Footing 10 Foot: A support for the foundation of a house that also helps prevent settling. It is typically made of concrete reinforced with rebar, but can also be made of masonry or brick. It is usually built under a heavier part of the house like a wall or column, to distribute the weight of the house over a larger area.
11 Grade: The process of evening out the ground's surface, making it either flat or sloped.
glossary term picture Soil Test 12 Soil testing: Chemical analysis kit used to assess soil pH, and sometimes soil nutrients, for the purpose of making fertilizer recommendations (type, quantity, and frequency)

Cost to install a septic tank system varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.

Updated:
The information provided by our cost guides comes from a great variety of sources, including specialized publications and websites, cost studies, U.S. associations, reports from the U.S. government, contractors and subcontractors, material suppliers, material price services, and other vendor websites. For more information, read our Methodology and sources.
Septic tank system being installed
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Cost to install a septic tank system varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.

The information provided by our cost guides comes from a great variety of sources, including specialized publications and websites, cost studies, U.S. associations, reports from the U.S. government, contractors and subcontractors, material suppliers, material price services, and other vendor websites. For more information, read our Methodology and sources.