Ashburn, VA

Average cost to Finish a Basement ranges from
$19,112 – $35,940

The average cost to remodel and finish a basement is $30,230 for materials and installation with most homeowners spending between $19,112 and $35,940 for a 1,200 sqft. basement with bathroom. The price can vary greatly by region (and even by zip code). Get free estimates from pros near you.

How much does it cost to finish a basement?

Author: Daniel W.
Millions of people ask HomeGuide for cost estimates every year. We track the estimates they get from local companies, then we share those prices with you.

Basement Finishing Cost: The Complete Guide


You’ve been looking at the space in your basement for a while now, thinking about how you could finish it out into an extra office, bedroom, game room, or living space. But how much would it cost?

The average cost to finish out an existing basement for a 1,200 square foot home is around $25/sqft, meaning you should expect to spend an average of $30,500, or around $15,250 if your basement is only a half/partial basement. A 1,200 sqft home is the average size of a house basement built in the ‘70s—early ‘90s.

This pricing guide covers:

Cost Factors, Materials, and Labor

The amount you end up spending on your basement will likely be affected by your long-term plans for the home and your family. For example, many homeowners will elect to work with a budget of between 35% and 45% more if the plan is to stay in the home longer than ten years. If you’re turning the basement into something that could generate income by doing either long- or short-term rentals, then you might elect to spend that little bit more.

The average cost to finish a basement:

Basement Material Average Cost
Bathroom $2,500
Plumbing $2,150
Doors and Trim $2,400
Drywall $3,180
Electrical $1,800
Flooring $2,000
Framing $1,200
Paint $1,200
Media $300
Sub Total: $16,730
Labor $13,500
Total: $30,230

Where you live makes a difference in the final cost because the per hour rate for contractors will be different, and labor makes up a significant portion of your basement project cost.

The average time to finish out a 1,200 sqft basement is roughly five weeks. Regarding your return on investment, adding square footage to the home will increase its value by roughly $0.75 for every dollar spent on the project, plus the bonus of any rental-generated income.

Planning

Your layout options are not just about having a big play area; you can have extra bedrooms, a game room, a media area, bathroom, home office, and even storm shelter or a safe room. Once you’ve chosen the number of, and purposed, the rooms, the main focus of the planning component of the project is to ensure the most efficient use of space. Consider the following:

Spaces for sleeping

Floor space - An effective option for a bedroom in a basement is to have the long edge of it against a wall, which will allow for more floor and study space.

Storage - can be built on either side of the bed, and attached to the wall above the bed, as a more effective use of space. The storage options don’t have to be big, but keeping them from being spread out around the floor will make the room feel bigger.

Location of sleeping areas - bedrooms will need to be located around the outside edges of the basement to facilitate a quick and safe exit, and for emergency responders to gain entry.

Flexible lighting - Also look at attaching flexible-arm lamps to the wall above the bed to allow for cozy nighttime reading.

Bathroom planning

Light - Because there are smaller or no windows in a basement, you have to maximize any and all light sources. One way is to reflect light with chrome hardware and white cabinetry.

Basement Finishing Bathroom

Sewage backups - Because your new basement bathroom will be much lower (known as below grade) than any other plumbing in your home, steps have to be taken to prevent backups into the tub or sinks. Ask if your installer can install a backflow-prevention valve in the main drain line, or have a plumber do it. Also, a macerating toilet, which has a compact tank, can also handle the output from the sink, which will reduce the footprint of the waste produced before it is pumped into the main line.

Damp - Basements, especially in damper regions of the country, are usually more prone to moisture accumulation and its resulting damage. Add a humidistat to the bathroom exhaust fan that will automatically turn it on when the air's too damp.

Think about hiring a contractor with basement bathroom remodeling experience due to the additional knowledge they would have in dealing with the aforementioned issues.

Living areas

Furniture – look for smaller alternatives to a traditionally sized sofa.

Deco - The two elements that will make any basement more enjoyable for your family or guests are roominess and brightness. Careful selection of your furnishings and decorations can contribute to this atmosphere.

Basement Finishing Living Room

If you are a dab hand at making such decisions, you can avoid soliciting the services of a professional, but a professional may have more experience in maximizing basement spaces and be more aware of products that work well in that environment.

Windows - For the most part, the majority of the windows in your basement will be hopper windows, except in the case of a well window for emergency exits. When standing in a basement room, hopper windows are high and not very tall, and it is possible to distract from this reality by installing cabinets below the hopper windows so your eyes are not drawn to the windows.

Functional Space Planning

Areas in the basement that are purely functional don’t have to be as plush as the rest of your new development, but they should still be planned in advance along with the living spaces.

Washers and dryers - can take up a lot of space in a side-by-side configuration, so look at installing stackable versions for your laundry needs. They only take up half the space and free up space for installing a sink plus some shelving.

Entry point - you can install hooks to hang items of clothing like coats, etc., and opt out of traditional solutions like a coat closet, thus minimizing the impact to the total available floor space.

Entertainment

Screen glare - If you are including a home theatre section or just an area with a TV, it can be situated in a part of the basement with the least amount of natural light to help eliminate glare on the screen and develop more of a home-theater atmosphere.

Basement Finishing Luxury with Pool Table

Snacking - With the future use of the home theatre in mind, consider the location of the mini fridge to store snacks and beverages so that people won’t be passing in front of the screen for refreshments during a movie or big game.

Natural light - Wherever you think the most people will gather—whether around a pool table, ping pong table, or a dart board—locate it in an area with the highest amount of natural light.

Room temperatures

Thermostats - If you live in a region that gets a real winter, consider opting for a separate thermostat for the basement, since its climate will likely differ from upstairs.

Vents - Have the heating and cooling vents installed close to the floor instead of installing them in the ceiling.

Radiant heating - In areas where it is common to experience extremely cold temperatures, you can install radiant mats or underlay, or even put it in the walls.

Fireplace - If you plan on installing a fireplace, look into getting a direct-vent gas fireplace so you won’t be taking up more space with firewood, and you won’t have to carry it up and down the stairs.

Convenience

Additional items to consider in relation to making basement living a little more convenient are:

  • Cell-phone booster to make sure you will always have a signal in the basement. $200
  • Network Wi-Fi extender so that you can avoid running cat 5 network cable in the basement. $100
  • Portable light that takes batteries and is rechargeable. $25
Or, a rechargeable plug-in LED flashlight, emergency power outage light for just $10.

Access to mechanicals

The standard rule of thumb when it comes to basement mechanicals is to leave between 2’–3’ of clearance, which should be enough for a maintenance person to walk around and do any work that needs to be done. This is true in the case of moving mechanicals or just boxing what is already in place.

Naturally, a contractor that includes an engineer and architect on his/her team will be able to give you the most accurate layout plan of all, like Renovate Max in Santa Clara, CA, who says, “From vision to completion, we provide design ideas, either interior or exterior/ architectural /engineering calculation.”

Flooring materials

Listed in order of least to most expensive, these are the average installed costs per square foot for the different options in flooring:

Flooring Material Cost Per Sqft. Total for 1,200 Sqft.
Vinyl $1.66 $2,000
Carpet $3.00 $3,600
Laminate $4.70 $2,640
Bamboo $7.30 $8,760
Tile $7.50 $9,000
Hardwood $8.00 $9,600

Basement Finishing Living Room

  • Consider a flooring product that is durable and easy to clean, especially if there are younger people living downstairs.
  • If you want a wood finish appearance, look into faux-wood vinyl flooring, as it will hold up well in the case of any flooding and it doesn’t need to be waxed or polished like real wood.
  • Tile is good at handling moisture, and if you install larger tiles, there will fewer grout lines than with smaller tiles. For both the faux-wood and the tile flooring, a dark color will go a long way toward hiding the dirt compared to lighter colors.
  • Wall-to-wall carpet can deaden sound in a play area. Opt for synthetic fibers that resist mold and mildew.

Plumbing

Generally speaking, it is unlikely that your basement will be already plumbed and ready to deliver water. Adding the feature of a full bathroom in a space of about 40 square feet, including all the plumbing work, could range between $3,500–$5,000 as a line item on the final quote.

A sewage pump might be needed, since it is likely that the physical location of the toilet is now lower than the depth of your existing waste line. Sewage pumps can run anywhere from $290–$1,000 for the pump itself, and then there will be labor to install and connect it to the waste line.

When planning for the pump, it is a good idea to factor in a replacement pump and a backup battery for the main pump. That way, if there is a power outage, or your main pump fails, you will not be left with nasty consequences.

Alternatively, there are also water-powered backup pumps that operate on the pressure in your municipality water line. These start at around $200.

Insulation

Insulation will help to control the temperature and moisture, and it can act as an additional soundproofing agent to minimize outside noises. See if your contractor carries insulation which includes a vapor barrier on each side, or look into spray foam insulation. The basement building code may have regulations regarding what types of insulation are permitted in your area.

Regulatory compliance

Second Exit

Local building authorities will either have put together their own rules or follow the standards of the International Code Council (ICC), and most states require an egress, or an additional exit, from the basement in addition to the stairs leading down into the basement. From a regulatory perspective, this is one to really pay close attention to.

Basements with one or more bedrooms are required to have an emergency exit and rescue openings in each bedroom. An exit is required for other spaces used for living, eating, or cooking if there is no bedroom. This would include offices and recreation rooms, but only one exit is required in the bedroom for a combined bedroom and office finish out.

Egress Requirements

The egress window or door has to open easily to the outside of the home without the use of keys or tools. A window must open wide by at least 20” and high by at least 24”, with a crawl space of at least 5.7 square feet. It can’t have a sill higher than 44” above the floor unless a permanent ladder or steps are installed. Once out the window, you must have a window-well floor space of nine square feet dug. The reason for such stringent rules is in case of fire—facilitating safety both for the exiting habitant and the firefighter.

Basement Egress Options

According to “Know the Rules for Finished Basements,” on bobvila.com, “here are the basics of a typical basement egress window system:

  1. A “buck,” poured into the wall during new construction, creates a frame in the foundation wall.
  2. A window well keeps the earth away from the basement window. It can be bolted to a buck or, if a remodel, to the foundation wall.
  3. A basement window can be of any style that meets code requirements.
  4. Safety grates or grilles keep people and pets from falling into the well.
  5. Well covers keep debris from filling the well.
  6. Ladders or steps provide a way to get out of the well.”

You can buy complete egress kits from companies like Boman Kemp. Theirs is $950, code compliant, includes a window and an escape ladder, and can be installed in retrofits and in new homes. You can also buy terraced-step window-well systems or pre-cast concrete stairwells with steel doors. They can be installed in a few hours. Have your egress custom built, or have your basement finish contractor install an egress window kit, at a cost of $200 to $3,000.

  • Basement egress aluminum ladder - from $70
  • Galvanized stairs - from $200
  • Egress window well: one-piece plastic egress structure with steps built into the molding - from $600 to $1,500
  • A complete system: one-piece well, ladder, window, and well cover - from $1.300 to $3,500

Some of the more expensive solutions, while generally made from plastic or fiberglass, have been fabricated to look like brick or wood. Some well covers are a clear dome structure that allows light in, while others are made from similar plastic to the well and block light from coming in when closed. The reasons for the addition of the lid is to stop kids from falling, and to keep rain and/or snow out.

Additional basement building codes

Any electrical or plumbing work, such as the addition of radiant heating or a bathroom, will usually have to be inspected. In addition to regulations you may have at the local city or state level, the ICC building codes apply no matter where you live. The sections listed below contain references that are specific to basements:

  1. Ceiling height in habitable spaces must be seven feet or more, but can include beams and ducts.
  2. An emergency escape and rescue opening must be in each bedroom unless the basement is only used for storing mechanical equipment or has at least one egress plus a sprinkler system.
  3. Smoke alarms must be in each bedroom.
  4. Carbon monoxide alarms must be installed to alert the whole building.
  5. Wood columns/beams and wood-based products must be pretreated against decay.
  6. Don’t use foam plastic if the area is known for subterranean termites.
  7. The lowest floor should be built to be flood resistant.
  8. Flood hazard areas have special construction rules.

Upgrades

Upgrade wall panels to minimize the risk of mold

If your basement is finished out with standard drywall, there is a strong possibility that mold could accumulate on the coating, which is made of paper. Once that happens, in addition to having mold, the gypsum inside the drywall runs a risk of crumbling. As alternatives, talk to your contractor about Georgia-Pacific's non-paper-faced DensArmor Plus high-performance interior panels, or USG's Sheetrock Brand Mold Tough gypsum panels. In a standard lab test for mold resistance, these two products received the highest scores.

Waterproofing

Consider hiring a contractor with decades of experience in sealing the home from water intrusion, like TP Renovations in Portland, OR, a certified installer for DuraDek waterproof membranes. Or one like BCR Construction Division in Coarl Gables, FL, who specializes in water, fire, smoke, and mold damage restoration services.

Faux wood flooring

In addition, as mentioned above, consider looking into faux-wood vinyl flooring for your basement flooring. Thanks to modern high-tech printing techniques, this gives scratch-resistant floating vinyl boards a realistic wood-like appearance.

Hung ceiling for plumbing access

For most people, the very mention of ceiling tiles conjures up images of the one look common to nearly every single corporate environment. Thankfully, in recent years, ceiling tiles have stepped out of the one design fits all look, allowing a basement ceiling to look much more creative and interesting than a boardroom. Remember to check the most current ICC basement ceiling height regulations when deciding on a hung ceiling, as a hung ceiling will mean it is closer to the floor.

Recessed lighting

Overhead space is a precious commodity in any home and especially in a basement. If you can install recessed lighting, then you can maintain the maximum overhead space possible.

Soundproofing

  • Add fiberglass batts without a vapor barrier in between the joists. After that, fasten drywall in either one or two layers. This process will facilitate the isolation of the drywall from the joists, which stops sound wave vibrations. In addition, you can place sound-dampening, anti-vibration mats or pads between the drywall layers.
  • Minimize connections between ducts in the basement and upper floors to reduce noise transmission.

Project expectations

According to Craftsman, a typical basement finish-out construction schedule project plan for a 1,200 sqft basement includes two bedrooms, one bathroom, a wet bar, and a fireplace. The following plan is split up into what to expect each week or so.

Week 1

  • Days 1–2: Framing
  • Days 3–5: HVAC, plumbing rough in, electrical rough in, gas rough in, set fireplace unit

Week 2

  • Day 8: Deliver drywall, install insulation, rough stage inspections
  • Days 9–10: Hang drywall
  • Days 11–16: Tape, mud, and texture drywall

Week 3

  • Days 17–18: Install trim, doors, windowsills, mantle at fireplace
  • Days 19–23: Painting

Week 4

  • Days 24–26: Install lights and electrical trim, HVAC registers and trim, shower and floor tile
  • Day 29: Install cabinets, door hardware
  • Days 30–31: Masonry at fireplace, template for countertops, mirrors and glass shower door

Week 5

  • Day 32: Drywall touchups, finish setup and start fireplace
  • Day 33: Install countertops
  • Day 36: Install plumbing trim, install shower door and mirror
  • Day 37: Install carpet

Week 6

  • Day 39: Final inspections, painting touchups
  • Day 40: Final cleaning, final walkthrough

Ways to save on the project cost

Depending on your available time, skills, number of required tools, and your level of courage, you could do the following work in advance:

Water leaks - Look for and repair minor leaks. “Often a few simple fixes will solve a moisture problem,” says This Old House general contractor Tom Silva. His tips:

  • Install diverters to send gutter water at least 10 feet from the foundation.
  • Slope soil away from the foundation.
  • Seal small cracks or gaps around pipes with concrete-patching compound.
  • Fill larger cracks inside and out with hydraulic cement, which expands as it cures. A structural engineer should inspect any cracks that are wider than a pencil.

Brothers Handyman in Washington, DC, say, “Running toilets can have relatively simple fixes that can save you lots of money on your utility bills. Leaking faucets and shower fixtures can make quite a mess and damage wood, making for costly repairs. Nip it in the bud and get them fixed before they become an issue.”

Insulation - Take care of some initial insulation in the basement by adding slip foam insulation on your cold-water pipes to prevent condensation from building up and then dripping inside your drywall or ceiling. Put slip foam on the hot-water pipes to prevent the loss of any heat. This should be done before boxing in any of the pipes in the basement.

Basement finishing kits

If you want to have your basement project completed faster than having the work done from scratch, use a basement finishing kit. Basement finishing kits can include everything from framing, walls, flooring structure, and even ceiling finishes, while other kits just focus on delivering a framing and wall surface solution. Many solutions in this space are well suited to making the planning of your basement space layout a straightforward process, because they are modular.

Basement Finishing Wood Vintage Kits

When it comes to the walls, there are some key design features that set the kits apart when compared to a typical installation:

  1. Insulation is already attached to each wall panel, so there is no extra effort or expense required for insulating your basement.
  2. Generally, the panels are designed with a tongue and groove feature that allows them to be fitted together easily.
  3. Your basement kit wall panels are removable, which allows for easy access to both plumbing and electrical infrastructure.
  4. Most companies do not use drywall, which has a layer of paper as the finish surface that is prone to mold accumulation; instead, they use a non-organic blend of ingredients that will dry quickly, if flooding occurs, and keep basement moisture at bay.

Some products include:

Owens Corning Basement Finishing System - $50–$70/sqft.

The wall panels are durable, insulated fiberboards (with an insulation rating of R-11), that are installed over existing walls. They are made with a DuPont Teflon for resisting stains and easy cleaning. The estimated time to have all the walls fully in place is roughly two weeks. These finish systems also include a choice of two different types of suspended ceilings, but they do not include any flooring.

Total Basement Finishing

This company provides walls, flooring, ceilings, and even windows at one point of purchase. The walls are insulated to a rating of R-13. The time it takes to complete a standard installation is roughly two weeks.

Champion Basement Living Systems

Champion features a wall system that allows for a livable and useable space within two weeks, on average. Walls are rated as R-13 for their insulation and are moisture, mold, and mildew resistant.

The feature that sets them apart is their excellent acoustics. If you want a home theatre, consider the Champion fabric-covered walls that provide a 95% NCR (Noise Reduction Coefficient) rating—it absorbs 95% of all sound into the walls and ceiling, which will provide a better home theatre experience while insulating the upstairs living areas from sound from the basement.

By comparison, drywall has a 5% NCR (Noise Reduction Coefficient) rating, which means that it only absorbs 5% of all sounds into the walls and ceiling.

Payment plans

Most contractors will require payment upfront for the materials each week, while others ask for 50%. Only give your money to a contractor who has passed the checklist below. Too many homeowners have handed over their project savings and never seen the contractor again. We at HomeGuide hope we have provided enough information to make sure this doesn’t happen to you.

One HomeGuide contractor, Artisans Home Repair in Richardson, TX, for example, says, “We charge 78.00 flat fee for the bid, which is rebated to the customer after the work has been completed, which makes the bid free! All other jobs that will take anywhere from an hour to 2 days, will be billed on an hourly basis. The first hour is $145 and every hour after that will be $95 billed in increments of 15 minutes which divides into $23.75 per 15-minute increment.”

Colorado Log Home Builders in Denver, CO, say, “We usually enter into an open book with a fixed fee contract but sometimes have a lump sum agreement depending on what the client prefers.”

Choosing a contractor

You want the best contractor for the project at a price within your budget, but don’t take the lowest bid unless the contractors you’re researching have most of the following:

  • Are A+ rated members of the Better Business Bureau
  • Have been finishing out basements for at least five years
  • Offer a warranty on labor and materials
  • Are insured and bonded
  • Are rated highly on HomeGuide
  • Include all cleanup in the quote
  • Offer exact begin and end dates

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