*The Angi rating for Basement Remodel companies in Kingstowne, VA is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Basement Remodel needs.
*The HomeAdvisor rating for Basement Remodel companies in Kingstowne, VA is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Basement Remodel needs.
Last update on June 02, 2025
All Renovations was started by a local graduate of George Washington University. We are fully licensed in all trade work including building, electrical and plumbing . We have always put our customers first in delivering what we promise without any gimmicks. The reputation of our company is proven through our satisfactory track record including winning the highly coveted Angie’s List Super Service Award and being selected as a Best Pick Report contractor on numerous occasions. The staff at our company values your time with prompt on site visits, quick turnaround in providing cost estimates, and a responsive attitude until job completion. We can assure you that our pricing and written warranty provides value in your investment when compared with other professionally licensed contractors. Due to our staffing requirements we are only able to take on jobs $10k or higher.
"I am giving All Renovations 5 stars for the basement renovation in large part because of Adrian’s excellent craftsmanship and attention to detail. Our job was pretty extensive. It included moving support columns, demo and rebuild exterior stairway, adding a full bath, extending the finished/framed portion of the basement, moving the circuit-breaker panel, and re-doing our half-bath. The job took 6 months, which was about twice as long as we expected. Omar was always very responsive and provided good feedback. Adrian is very good at explaining things and soliciting your input when options/alternatives exist. He definitely does not take short-cuts if quality would suffer. He is also very considerate/careful inside your home and cleans-up after himself. Our $102k project ballooned to $125k, mostly due to nice to have add-ons and unforeseen issues. But there were several items I feel should have been caught at the contract onset. E.g. the need for a floor drain ($900), considering that we were getting rid of the utility sink basin. There was also an extra $4k to replace the drywall in the half bath since the existing paint was too textured (sponge) to paint over. But we were very pleased with the outcome and would definitely recommend All Renovations."
Shane G on March 2025
All Renovations was started by a local graduate of George Washington University. We are fully licensed in all trade work including building, electrical and plumbing . We have always put our customers first in delivering what we promise without any gimmicks. The reputation of our company is proven through our satisfactory track record including winning the highly coveted Angie’s List Super Service Award and being selected as a Best Pick Report contractor on numerous occasions. The staff at our company values your time with prompt on site visits, quick turnaround in providing cost estimates, and a responsive attitude until job completion. We can assure you that our pricing and written warranty provides value in your investment when compared with other professionally licensed contractors. Due to our staffing requirements we are only able to take on jobs $10k or higher.
"I am giving All Renovations 5 stars for the basement renovation in large part because of Adrian’s excellent craftsmanship and attention to detail. Our job was pretty extensive. It included moving support columns, demo and rebuild exterior stairway, adding a full bath, extending the finished/framed portion of the basement, moving the circuit-breaker panel, and re-doing our half-bath. The job took 6 months, which was about twice as long as we expected. Omar was always very responsive and provided good feedback. Adrian is very good at explaining things and soliciting your input when options/alternatives exist. He definitely does not take short-cuts if quality would suffer. He is also very considerate/careful inside your home and cleans-up after himself. Our $102k project ballooned to $125k, mostly due to nice to have add-ons and unforeseen issues. But there were several items I feel should have been caught at the contract onset. E.g. the need for a floor drain ($900), considering that we were getting rid of the utility sink basin. There was also an extra $4k to replace the drywall in the half bath since the existing paint was too textured (sponge) to paint over. But we were very pleased with the outcome and would definitely recommend All Renovations."
Shane G on March 2025
BasementRemodeling.com / Basement Masters - licensed and insured, award winning Basement Remodeling and Finishing company. Highest rated basement renovation contractor in Maryland. Finished Basements are our specialty. We specialize in custom basement remodeling and finishing and other large-scale remodels. We offer free in home and over-the-phone estimate and consultation. Here at BasementRemodeling.com we believe that QUALITY AND EXCEPTIONAL CRAFTSMANSHIP must always come along with AFFORDABILITY. keywords: finished basement basements remodeling.
"I hired Basementremodeling.com for the gutting and rebuilding of my entire basement on the recommendation of my next door neighbor, and they did a fantastic job. I had been looking at several contractors, and the professionalism and dedication of this firm was really impressive. Their planning and design team were top notch. Everything was transparent. The crews worked their hearts out, they were super polite and tidy, and their attention to detail, flexibility and willingness to work with me on last minute changes was superb. I'd hire basementremodelling.com again without question! Thanks guys!"
Dan L on May 2025
BasementRemodeling.com / Basement Masters - licensed and insured, award winning Basement Remodeling and Finishing company. Highest rated basement renovation contractor in Maryland. Finished Basements are our specialty. We specialize in custom basement remodeling and finishing and other large-scale remodels. We offer free in home and over-the-phone estimate and consultation. Here at BasementRemodeling.com we believe that QUALITY AND EXCEPTIONAL CRAFTSMANSHIP must always come along with AFFORDABILITY. keywords: finished basement basements remodeling.
"I hired Basementremodeling.com for the gutting and rebuilding of my entire basement on the recommendation of my next door neighbor, and they did a fantastic job. I had been looking at several contractors, and the professionalism and dedication of this firm was really impressive. Their planning and design team were top notch. Everything was transparent. The crews worked their hearts out, they were super polite and tidy, and their attention to detail, flexibility and willingness to work with me on last minute changes was superb. I'd hire basementremodelling.com again without question! Thanks guys!"
Dan L on May 2025
Serving Northern Virginia, DiJulio Contracting, LLC is a Construction and Remodeling General Contractor. We are a fully licensed and insured Class A contractor in Northern Virginia. Our core business is built around Basement Finishing and Bathroom remodeling. We are competitively priced across all fields, and adequately staff and supervise our projects to ensure the work is completed with the highest quality and within reasonable time frames. When you call us for an estimate, we will provide you with a detailed plan, design specifications, schedule, and a complete proposal package with much more info. This is all provided at no cost to you. We do not underbid jobs and try to recover costs with hidden, ambiguous extra charges during the project, as many unethical, unlicensed contractors do. When you accept the contract terms, the project should progress almost flawlessly without any additional costs. Tambien, se habla Espanol. So contact us today. Credit payments are an accepted method of payment for projects that meet specific criteria. Also covering Alexandria City, Fairfax City, and City of Falls Church.
"Scott is a reliable and a very knowledgeable contractor. Only with looking at a simple picture, he knew what kind of repair was needed for the leaks on my walls coming from the deck. Scott's team came to my house and fixed the deck leaks in a matter of hours. The professional and very detailed quality work, was accomplished with honesty and timelines. I would recommend DiJulio contracting for any home repairs or home improvements."
Yenny G on January 2021
Serving Northern Virginia, DiJulio Contracting, LLC is a Construction and Remodeling General Contractor. We are a fully licensed and insured Class A contractor in Northern Virginia. Our core business is built around Basement Finishing and Bathroom remodeling. We are competitively priced across all fields, and adequately staff and supervise our projects to ensure the work is completed with the highest quality and within reasonable time frames. When you call us for an estimate, we will provide you with a detailed plan, design specifications, schedule, and a complete proposal package with much more info. This is all provided at no cost to you. We do not underbid jobs and try to recover costs with hidden, ambiguous extra charges during the project, as many unethical, unlicensed contractors do. When you accept the contract terms, the project should progress almost flawlessly without any additional costs. Tambien, se habla Espanol. So contact us today. Credit payments are an accepted method of payment for projects that meet specific criteria. Also covering Alexandria City, Fairfax City, and City of Falls Church.
"Scott is a reliable and a very knowledgeable contractor. Only with looking at a simple picture, he knew what kind of repair was needed for the leaks on my walls coming from the deck. Scott's team came to my house and fixed the deck leaks in a matter of hours. The professional and very detailed quality work, was accomplished with honesty and timelines. I would recommend DiJulio contracting for any home repairs or home improvements."
Yenny G on January 2021
Stephen Radomsky has formed Capstone Remodeling after fifteen years of working as a professional carpenter for a premier Northern Virginia remodeling company. (please send email via company website http://capstoneremodelinginc.com/) Mr. Radomsky's goal is to reduce the stress associated with home remodeling by treating you like a member of his own family. He holds a Class B (BLD) Contractor's License issued by the Commonwealth of Virginia and insurance.He offers a free in-home consultation to discuss your goals; timeline; options; and, budget. Mr. Radomsky works around your schedule; keeps a clean and organized job site; personally performs or supervises all work done in your home to ensure that it is of the highest quality. As such, he specializes in working wtih customers that are open to working with high quality materials and finishes of their choosing. Mr. Radomsky strives to make every customer a delighted, lifelong customer.
"Very satisfied. Work crew assigned was superb: timely, clean workspace, attention to detail, completely responsive."
Mr. R on May 2025
Stephen Radomsky has formed Capstone Remodeling after fifteen years of working as a professional carpenter for a premier Northern Virginia remodeling company. (please send email via company website http://capstoneremodelinginc.com/) Mr. Radomsky's goal is to reduce the stress associated with home remodeling by treating you like a member of his own family. He holds a Class B (BLD) Contractor's License issued by the Commonwealth of Virginia and insurance.He offers a free in-home consultation to discuss your goals; timeline; options; and, budget. Mr. Radomsky works around your schedule; keeps a clean and organized job site; personally performs or supervises all work done in your home to ensure that it is of the highest quality. As such, he specializes in working wtih customers that are open to working with high quality materials and finishes of their choosing. Mr. Radomsky strives to make every customer a delighted, lifelong customer.
"Very satisfied. Work crew assigned was superb: timely, clean workspace, attention to detail, completely responsive."
Mr. R on May 2025
We specialize in full home remodeling, kitchen and bathroom, interior and exterior painting, roofing and everything in-between, we are specialized with insurance claim. As an award-winning company, we deliver high-quality work tailored to your needs and budget. Communication is our priority—contact us today for a free estimate!
"I just had Potts Brothers redo my bathroom and basement, and honestly, they killed it. The whole process was super easy, and the results are amazing. Youssef and Peter were awesome to work with. Youssef helped me figure out the design and had some great ideas that made everything look even better than I imagined. Peter oversaw the work and together with omar and the rest of the team, and they made sure everything was done right and on time. The bathroom is now my favorite part of the house—it’s modern, functional, and just looks so good. The basement went from being a storage dump to a space I actually want to hang out in. The quality of the work is really solid, and you can tell they care about the little details. What I really appreciated was how communicative they were. Youssef and Peter kept me in the loop the whole time, answered all my random questions, and made sure I was happy with how things were going. If you’re thinking about a remodel, I’d definitely recommend Potts Brothers. Youssef and Peter are a great team, and they made the whole thing stress-free. 10/10!"
Therese J on January 2025
We specialize in full home remodeling, kitchen and bathroom, interior and exterior painting, roofing and everything in-between, we are specialized with insurance claim. As an award-winning company, we deliver high-quality work tailored to your needs and budget. Communication is our priority—contact us today for a free estimate!
"I just had Potts Brothers redo my bathroom and basement, and honestly, they killed it. The whole process was super easy, and the results are amazing. Youssef and Peter were awesome to work with. Youssef helped me figure out the design and had some great ideas that made everything look even better than I imagined. Peter oversaw the work and together with omar and the rest of the team, and they made sure everything was done right and on time. The bathroom is now my favorite part of the house—it’s modern, functional, and just looks so good. The basement went from being a storage dump to a space I actually want to hang out in. The quality of the work is really solid, and you can tell they care about the little details. What I really appreciated was how communicative they were. Youssef and Peter kept me in the loop the whole time, answered all my random questions, and made sure I was happy with how things were going. If you’re thinking about a remodel, I’d definitely recommend Potts Brothers. Youssef and Peter are a great team, and they made the whole thing stress-free. 10/10!"
Therese J on January 2025
KBA Kitchen and Bath: Transforming Homes with Excellence for Over 25 Years. Proudly Serving Fairfax County and Fauquier County.
"We would like to say thank you to KBA Kitchen & Bath Design & Build for a great job remodeling our two upstairs bathrooms. The two bathrooms were completely renovated in 5 weeks, but it could have been finished even sooner if we hadn’t selected a premium option for our shower glass enclosure. The entire project was started and finished between January 21, 2025 until February 28, 2025, which included the crew working two Saturdays, which shows their dedication in getting the job done. We were very impressed with KBA over the entire project! Specifically, we were impressed at how smooth and efficient the entire process was. It was seamless – from the initial consultation to the execution of the job. The designer, Anna, was very thorough and helpful in sketching the designs of new bathrooms and offering advice on recommended materials for the bathroom, to include going above and beyond in helping us choose just the right paint colors to perfectly blend with our newly installed bathroom accessories. Anna and Ervin both made after hour visits to provide their insight on color schemes and where bathroom accessories should be installed and look best. The lead project manager, Ervin, was always there to answer our questions, and he went out of his way to always ensure we were happy customers! Ervin also visited on many occasions to give us updates on project progress and keeping his crew updated on any changes. The installation team always showed up on time, left the work area clean, and went above and beyond to make our design a reality. Anna, Ervin and the crew were always very friendly, professional, and helpful throughout this project. We couldn’t be happier with the outcome as we absolutely love our bathrooms! We highly recommend choosing KBA for your next home project!"
Andrew R on March 2025
KBA Kitchen and Bath: Transforming Homes with Excellence for Over 25 Years. Proudly Serving Fairfax County and Fauquier County.
"We would like to say thank you to KBA Kitchen & Bath Design & Build for a great job remodeling our two upstairs bathrooms. The two bathrooms were completely renovated in 5 weeks, but it could have been finished even sooner if we hadn’t selected a premium option for our shower glass enclosure. The entire project was started and finished between January 21, 2025 until February 28, 2025, which included the crew working two Saturdays, which shows their dedication in getting the job done. We were very impressed with KBA over the entire project! Specifically, we were impressed at how smooth and efficient the entire process was. It was seamless – from the initial consultation to the execution of the job. The designer, Anna, was very thorough and helpful in sketching the designs of new bathrooms and offering advice on recommended materials for the bathroom, to include going above and beyond in helping us choose just the right paint colors to perfectly blend with our newly installed bathroom accessories. Anna and Ervin both made after hour visits to provide their insight on color schemes and where bathroom accessories should be installed and look best. The lead project manager, Ervin, was always there to answer our questions, and he went out of his way to always ensure we were happy customers! Ervin also visited on many occasions to give us updates on project progress and keeping his crew updated on any changes. The installation team always showed up on time, left the work area clean, and went above and beyond to make our design a reality. Anna, Ervin and the crew were always very friendly, professional, and helpful throughout this project. We couldn’t be happier with the outcome as we absolutely love our bathrooms! We highly recommend choosing KBA for your next home project!"
Andrew R on March 2025
Whether you want to remodel your existing home or build a brand new one, Thomas Custom Builders can help. Our 70+ years of combined experience as Northern Virginia general contractors and our commitment to quality ensures your custom construction or design-build project will be a success. Be it a master suite, custom kitchen or home addition, we dig deep to learn what’s making you spend your time and resources on this particular project. We honestly discuss the costs associated with your goals, then we deliver what we do best: excellence in custom remodeling. The only thing that counts is finishing your job exactly the way you want it. No compromise.
"From initial design meeting to project completion Thomas Custom Builders kept promises, delivered outstanding work on time and on budget and exceeded our expectations in every way. Their on site team did everything they could to keep the work place clean and tidy so as disrupt our home life as little as possible. Team leadership kept us informed and made sure our questions were answered promptly. They are excellent tradesmen with exceptional skills. I’d give them 10 stars if I could."
Calvin S on March 2025
Whether you want to remodel your existing home or build a brand new one, Thomas Custom Builders can help. Our 70+ years of combined experience as Northern Virginia general contractors and our commitment to quality ensures your custom construction or design-build project will be a success. Be it a master suite, custom kitchen or home addition, we dig deep to learn what’s making you spend your time and resources on this particular project. We honestly discuss the costs associated with your goals, then we deliver what we do best: excellence in custom remodeling. The only thing that counts is finishing your job exactly the way you want it. No compromise.
"From initial design meeting to project completion Thomas Custom Builders kept promises, delivered outstanding work on time and on budget and exceeded our expectations in every way. Their on site team did everything they could to keep the work place clean and tidy so as disrupt our home life as little as possible. Team leadership kept us informed and made sure our questions were answered promptly. They are excellent tradesmen with exceptional skills. I’d give them 10 stars if I could."
Calvin S on March 2025
SELECT Kitchen & Bath is a leading design and remodel company specializing in kitchens and bathrooms, working in the Northern VA and Washington DC area for the past twenty years. We’ll create your custom gourmet kitchen or replace your galley kitchen; we’ll create your master bath spa or re-do the children’s bath. Check out our pictures. We offer complete kitchen and bath design and remodeling services and enjoy an excellent reputation for providing a high level of personal service and quality of workmanship throughout our entire design and remodel process. Just ask around. SELECT Kitchen & Bath is owned by our key design and production staff who are dedicated to the success of your project and ensuring your expectations are surpassed.
"The short version of this review is we were very happy with the work Select Kitchen and Bath did for us and would not hesitate to use them again. Our project, which was completed in January 2025, consisted of a complete remodel of two full bathrooms which were vintage 1983. Amanda was our designer, Mark was the lead installer, and John was the project manager. All three of them provided welcome suggestions, good guidance and advice throughout the process… starting with clear and transparent service agreements. Select was very accommodating with scheduling and access to the house / workspaces. Questions were answered promptly by Amanda, Mark and John, and any concerns were addressed to our satisfaction. Our new bathrooms are great!"
Wendy R on May 2025
SELECT Kitchen & Bath is a leading design and remodel company specializing in kitchens and bathrooms, working in the Northern VA and Washington DC area for the past twenty years. We’ll create your custom gourmet kitchen or replace your galley kitchen; we’ll create your master bath spa or re-do the children’s bath. Check out our pictures. We offer complete kitchen and bath design and remodeling services and enjoy an excellent reputation for providing a high level of personal service and quality of workmanship throughout our entire design and remodel process. Just ask around. SELECT Kitchen & Bath is owned by our key design and production staff who are dedicated to the success of your project and ensuring your expectations are surpassed.
"The short version of this review is we were very happy with the work Select Kitchen and Bath did for us and would not hesitate to use them again. Our project, which was completed in January 2025, consisted of a complete remodel of two full bathrooms which were vintage 1983. Amanda was our designer, Mark was the lead installer, and John was the project manager. All three of them provided welcome suggestions, good guidance and advice throughout the process… starting with clear and transparent service agreements. Select was very accommodating with scheduling and access to the house / workspaces. Questions were answered promptly by Amanda, Mark and John, and any concerns were addressed to our satisfaction. Our new bathrooms are great!"
Wendy R on May 2025
Two Brothers Handyman and Home Improvement Service has 20+ years experience and a "CLASS A LICENSE IN VA & DC". We love every type of project from large scale renovations to even the smallest of jobs! We specialize in quality workmanship at affordable prices. We take pride in maintaining a consistently high-caliber level of work that comes with a satisfaction guarantee. Open and honest lines of communication with our clients during every step of the project is key to building relationships with successful outcomes. Washington DC License #2705168243, Expiration 5/31/2020.
"Ruben and the team did such a great job on the first project (2-3yrs ago) that I asked them to come back and finish my condo's water heater closet, which showed wear and tear from past water damage. They did a fantastic job in repairing the closet and adjacent living room's dry walls that it looked seamless to the rest of the unit. The team was always conscious of keeping the work area clean as they closed the area off with tarp and placed drop cloths down. I greatly appreciate the amount of high-quality work done in a short time span, especially when asked within two weeks of the project starting. I've recommended the team to my family and friends if they ever need a job done right by a team who is professional, courteous, and knowledgeable."
Sophia L on April 2025
Two Brothers Handyman and Home Improvement Service has 20+ years experience and a "CLASS A LICENSE IN VA & DC". We love every type of project from large scale renovations to even the smallest of jobs! We specialize in quality workmanship at affordable prices. We take pride in maintaining a consistently high-caliber level of work that comes with a satisfaction guarantee. Open and honest lines of communication with our clients during every step of the project is key to building relationships with successful outcomes. Washington DC License #2705168243, Expiration 5/31/2020.
"Ruben and the team did such a great job on the first project (2-3yrs ago) that I asked them to come back and finish my condo's water heater closet, which showed wear and tear from past water damage. They did a fantastic job in repairing the closet and adjacent living room's dry walls that it looked seamless to the rest of the unit. The team was always conscious of keeping the work area clean as they closed the area off with tarp and placed drop cloths down. I greatly appreciate the amount of high-quality work done in a short time span, especially when asked within two weeks of the project starting. I've recommended the team to my family and friends if they ever need a job done right by a team who is professional, courteous, and knowledgeable."
Sophia L on April 2025
We service residential and commercial needs. Whether you have a major remodel, home addition, minor home repairs, or anything in between we can help. We are a master plumbing and gas fitter as well. Quality, professionalism, and workmanship are the foundation of our business. Our biggest priority is our customers satisfaction. We provide competitive pricing without a lack of quality or professionalism. We are built on the premise that without our customers we wouldn't be here.
"Our deck caught fire last summer and we contracted Chris Heinz to do the rebuilding and replacement of our fire-damaged exterior. Chris was wonderful to work with! He worked with our insurance company tirelessly and also kept us informed every step of the way. He and his crew removed our old deck and siding, and built a new deck, a landing and stairs off our kitchen, installed a new sliding door and four windows, replaced our siding and trim, and installed new outdoor lighting. There were a few delays due to the pandemic and materials being readily unavailable from one of the manufacturers, but the timeframe was reasonable given the circumstances. Chris and his crew did an amazing job and we couldn’t be happier. We love our beautiful new deck and the new siding and trim. We get so many compliments from our neighbors and passers-by! We will definitely go to Chris next time we need work on our house and recommend him to everyone!"
Elizabeth B on June 2021
We service residential and commercial needs. Whether you have a major remodel, home addition, minor home repairs, or anything in between we can help. We are a master plumbing and gas fitter as well. Quality, professionalism, and workmanship are the foundation of our business. Our biggest priority is our customers satisfaction. We provide competitive pricing without a lack of quality or professionalism. We are built on the premise that without our customers we wouldn't be here.
"Our deck caught fire last summer and we contracted Chris Heinz to do the rebuilding and replacement of our fire-damaged exterior. Chris was wonderful to work with! He worked with our insurance company tirelessly and also kept us informed every step of the way. He and his crew removed our old deck and siding, and built a new deck, a landing and stairs off our kitchen, installed a new sliding door and four windows, replaced our siding and trim, and installed new outdoor lighting. There were a few delays due to the pandemic and materials being readily unavailable from one of the manufacturers, but the timeframe was reasonable given the circumstances. Chris and his crew did an amazing job and we couldn’t be happier. We love our beautiful new deck and the new siding and trim. We get so many compliments from our neighbors and passers-by! We will definitely go to Chris next time we need work on our house and recommend him to everyone!"
Elizabeth B on June 2021
Unless you have extensive experience in construction work, remodeling a basement is best left to a professional. There are several tasks associated with this project that require exact precision, including:
Replacing insulation
Replacing carpet or other flooring
Adding heating and cooling
Adjusting or adding walls and doors
Altering or adding plumbing elements
If any of these elements is done incorrectly, it could severely impact the quality of your basement remodel and be dangerous. Changing a basement often comes with code safety requirements, like egress windows and proper ventilation. Therefore, leaving it up to a professional is often the best decision.
The cost to finish a basement is $18,400 for the average homeowner. However, this cost could be as little as $2,800 or as much as $34,500, depending on the basement size and the materials needed. If your basement is already outfitted with electrical and plumbing, expect the cost to fall on the lower end.
For example, the drywall cost for this project averages around $1,750, but other features, like hiring a plumber, cost between $45 and $200 per hour.
The cost to remodel a basement is between $12,100 and $33,400 for the average homeowner. The price you pay can be as little as $3,500 or as much as $50,200, depending on the size and condition of your basement and the type of remodel you're doing.
If you're doing a simple project like adding a home office to your basement, you can expect to pay anywhere from $500 to $3,000. However, if you're adding a bathroom, which is an extensive project, you can expect to pay between $6,600 to $16,500.
Since DIYing a basement remodel isn't typically advised, there are some ways that you can still save money on this project without putting yourself in danger. Some ways to save money on a basement remodel include:
Painting walls yourself versus including in the cost of the remodel
Installing light fixtures yourself
Choosing prefabricated fixtures, like cabinets, over custom ones
Choosing a budget-friendly flooring option, like laminate or vinyl flooring, and add rugs where necessary
Although homeowners often use the terms basement remodeling and basement finishing interchangeably, they are quite different terms.
Finishing a basement is the process of taking a basement space that is not habitable and adding elements to make it usable. This includes adding plumbing, flooring, and insulation.
Remodeling a basement means taking an already existing finished basement and changing it, often by adding or removing walls, adding plumbing, or changing the existing flooring.