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Find Addition to existing structure builders in Watertown

Avatar for Matrix Basement Finishing

Matrix Basement Finishing

3050 N Kennicott Ave
4.54(
275
)
Approved Pro

Matrix Basement Finishing

3050 N Kennicott Ave
4.54(
275
)
Approved Pro
Customers say: Quality work
281 local quotes requested
16 years of experience

We are a locally owned and operated basement finishing specialist servicing the Chicagoland area. Our focus is providing clients with a clear, upfront vision of expectations through a design/build approach. Our free design service provides potential customers with a collaborative consultation geared towards budget, wants, needs and lifestyle.

"The basement looks amazing, the crew did an excellent job. They were efficient, kept to their schedules, and did great work."

Matthew R on October 2025

We are a locally owned and operated basement finishing specialist servicing the Chicagoland area. Our focus is providing clients with a clear, upfront vision of expectations through a design/build approach. Our free design service provides potential customers with a collaborative consultation geared towards budget, wants, needs and lifestyle.

"The basement looks amazing, the crew did an excellent job. They were efficient, kept to their schedules, and did great work."

Matthew R on October 2025


Avatar for Kool View Co.,Inc.

Kool View Co.,Inc.

1860 Bud Dr #104
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

Kool View Co.,Inc.

1860 Bud Dr #104
New on HomeAdvisorNew on HomeAdvisor
Approved Pro
93 local quotes requested
52 years of experience

Serving Southern Wisconsin and the greater Fox Valley area Kool View began business in 1973 selling glass coatings to save energy and stop furniture fading. In 1979 we were awarded a US. Department of Energy grant to study the "honeycomb" concept of window insulation. In 1982 we were granted a patent on our very own "Seal-A-Shade" product. We also began selling passive solar rooms. Over time passive solar sunrooms became our main product. We have built over 2000 sun room, patio room and room additions. Our construction focus has always been saving energy, improving the home environment and adding long term value to your home. If you have a unique design in mind or a challenging job site you have come to the right place! With with our trained staff of designers and craftsmen, Kool View is in the position to make your dream room an energy efficient reality. Kool View offers you the best of the "High Tech" corporate world while remaining a locally owned and operated business. We never forget that our customers are also our neighbors. Drop into our showroom or call us for a free, in-home estimate. We'd love to hear from you!

Serving Southern Wisconsin and the greater Fox Valley area Kool View began business in 1973 selling glass coatings to save energy and stop furniture fading. In 1979 we were awarded a US. Department of Energy grant to study the "honeycomb" concept of window insulation. In 1982 we were granted a patent on our very own "Seal-A-Shade" product. We also began selling passive solar rooms. Over time passive solar sunrooms became our main product. We have built over 2000 sun room, patio room and room additions. Our construction focus has always been saving energy, improving the home environment and adding long term value to your home. If you have a unique design in mind or a challenging job site you have come to the right place! With with our trained staff of designers and craftsmen, Kool View is in the position to make your dream room an energy efficient reality. Kool View offers you the best of the "High Tech" corporate world while remaining a locally owned and operated business. We never forget that our customers are also our neighbors. Drop into our showroom or call us for a free, in-home estimate. We'd love to hear from you!


Avatar for GRANZOW HOME IMPROVEMENT LLC

GRANZOW HOME IMPROVEMENT LLC

4.69(
13
)
Approved Pro

GRANZOW HOME IMPROVEMENT LLC

4.69(
13
)
Approved Pro
Customers say: Quality work
Recommended by 92% of Angi customers
Recommended by 92% of HomeAdvisor customers
66 local quotes requested

Ready to finish your basement? Granzow Home Improvement, LLC is a Basement Finishing Specialist that provides detail oriented, cost accurate formal proposals. We believe that the quality of every basement finish begins with the quality of the proposals we provide. Granzow Home Improvement, LLC is well known in the home improvement industry as a client-driven company that strives to meet the highest levels of quality and customer experience! With an A+ BBB rating and an Angie Pro rating of 4.9 out of a best 5 stars, we meet extending our hand to shake yours with the goal in mind of you extending yours to shake ours when you're basement finish is complete. You will enjoy our "no pressure" approach, FREE design assistance that comes with over 25 years of experience, professionally prepared plans, detail oriented proposals that come with a written guarantee for price accuracy, meaning no surprises, and our comprehensive written warranty that backs all services, including electrical, plumbing, and heating. Call now to schedule your FREE formal proposal.

"Granzow Home Improvement LLC exceeded all expectations in finishing our basement, and we couldn’t be happier with the results! From start to finish, Richard and Bob displayed professionalism, skill, and a genuine passion for their craft. The attention to detail was incredible—from the high-quality materials used to the flawless execution of every feature. They transformed our basement into a beautiful, functional space that feels like an extension of the rest of our home, not just an afterthought. Whether it was customizing a plan to fit our needs or ensuring seamless design transitions with the same materials used when our home was built, they listened to our ideas and brought them to life perfectly. Beyond the craftsmanship, they were punctual, respectful, and kept the work area tidy throughout the project. Richard communicated with us every step of the way, ensuring there were no surprises and that we were thrilled with the progress. If you’re looking for a reliable, talented contractor to bring your vision to life, look no further than Granzow Home Improvement LLC . We wholeheartedly recommend them and would hire them again in a heartbeat! Thank you, Richard and Bob, for making our dream basement a reality!"

Erica O on April 2025

Ready to finish your basement? Granzow Home Improvement, LLC is a Basement Finishing Specialist that provides detail oriented, cost accurate formal proposals. We believe that the quality of every basement finish begins with the quality of the proposals we provide. Granzow Home Improvement, LLC is well known in the home improvement industry as a client-driven company that strives to meet the highest levels of quality and customer experience! With an A+ BBB rating and an Angie Pro rating of 4.9 out of a best 5 stars, we meet extending our hand to shake yours with the goal in mind of you extending yours to shake ours when you're basement finish is complete. You will enjoy our "no pressure" approach, FREE design assistance that comes with over 25 years of experience, professionally prepared plans, detail oriented proposals that come with a written guarantee for price accuracy, meaning no surprises, and our comprehensive written warranty that backs all services, including electrical, plumbing, and heating. Call now to schedule your FREE formal proposal.

"Granzow Home Improvement LLC exceeded all expectations in finishing our basement, and we couldn’t be happier with the results! From start to finish, Richard and Bob displayed professionalism, skill, and a genuine passion for their craft. The attention to detail was incredible—from the high-quality materials used to the flawless execution of every feature. They transformed our basement into a beautiful, functional space that feels like an extension of the rest of our home, not just an afterthought. Whether it was customizing a plan to fit our needs or ensuring seamless design transitions with the same materials used when our home was built, they listened to our ideas and brought them to life perfectly. Beyond the craftsmanship, they were punctual, respectful, and kept the work area tidy throughout the project. Richard communicated with us every step of the way, ensuring there were no surprises and that we were thrilled with the progress. If you’re looking for a reliable, talented contractor to bring your vision to life, look no further than Granzow Home Improvement LLC . We wholeheartedly recommend them and would hire them again in a heartbeat! Thank you, Richard and Bob, for making our dream basement a reality!"

Erica O on April 2025


Avatar for MJL LawnCare

MJL LawnCare

W5235 Lakewood Cir
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

MJL LawnCare

W5235 Lakewood Cir
New on HomeAdvisorNew on HomeAdvisor
Approved Pro
271 local quotes requested
8 years of experience

Specializing in lawn care! We always guarantee your satisfaction and won’t leave until the job is done right. We take pride in ourselves and on the quality work we provide, while always delivering great customer service! Check out our services offered, then call --or-- click to schedule a free estimate today!

Specializing in lawn care! We always guarantee your satisfaction and won’t leave until the job is done right. We take pride in ourselves and on the quality work we provide, while always delivering great customer service! Check out our services offered, then call --or-- click to schedule a free estimate today!


Avatar for Kool View Co

Kool View Co

4701 Triangle St
4.38(
21
)
Approved Pro

Kool View Co

4701 Triangle St
4.38(
21
)
Approved Pro
Customers say: Quality work
75 local quotes requested
52 years of experience

SERVING SOUTHERN WISCONSIN AND THE FOX VALLEY AREAS Kool View began business in 1973 selling glass coatings to save energy and stop furniture fading. In 1979 we were awarded a US. Department of Energy grant to study the "honeycomb" concept of window insulation. In 1982 we were granted a patent on our very own "Seal-A-Shade" product. We also began selling passive solar rooms. Over time passive solar sunrooms became our main product. We have built over 2000 sun room, patio room and room additions. Our construction focus has always been saving energy, improving the home environment and adding long term value to your home. If you have a unique design in mind or a challenging job site you have come to the right place! With with our trained staff of designers and craftsmen, Kool View is in the position to make your dream room an energy efficient reality. Kool View offers you the best of the "High Tech" corporate world while remaining a locally owned and operated business. We never forget that our customers are also our neighbors. Drop into our showroom or call us for a free, in-home estimate. We'd love to hear from you!

"The final product is good and the price was good. The structure all seems to be high quality and with double pane windows it can hold the climate or out well as needed. With screens all around we can let the air move through when we want. The design process was a good experience, but we were not warned that our decisions in dimensions would result in difficulties with regulations and the electrical work. The lack of communication between sub-contractors during the process resulted in several delays. There were times when we were told there would be hand-off and it didn't happen until we prodded them. We kicked it off in the early spring and it didn't complete until August. Early on, the delays were unavoidable due to weather and ground conditions but after the foundation was in it took to long to complete the structure. The problem is not specifically the total time to complete but being left with very little time to replace the yard and driveway before winter."

Adam C on September 2018

SERVING SOUTHERN WISCONSIN AND THE FOX VALLEY AREAS Kool View began business in 1973 selling glass coatings to save energy and stop furniture fading. In 1979 we were awarded a US. Department of Energy grant to study the "honeycomb" concept of window insulation. In 1982 we were granted a patent on our very own "Seal-A-Shade" product. We also began selling passive solar rooms. Over time passive solar sunrooms became our main product. We have built over 2000 sun room, patio room and room additions. Our construction focus has always been saving energy, improving the home environment and adding long term value to your home. If you have a unique design in mind or a challenging job site you have come to the right place! With with our trained staff of designers and craftsmen, Kool View is in the position to make your dream room an energy efficient reality. Kool View offers you the best of the "High Tech" corporate world while remaining a locally owned and operated business. We never forget that our customers are also our neighbors. Drop into our showroom or call us for a free, in-home estimate. We'd love to hear from you!

"The final product is good and the price was good. The structure all seems to be high quality and with double pane windows it can hold the climate or out well as needed. With screens all around we can let the air move through when we want. The design process was a good experience, but we were not warned that our decisions in dimensions would result in difficulties with regulations and the electrical work. The lack of communication between sub-contractors during the process resulted in several delays. There were times when we were told there would be hand-off and it didn't happen until we prodded them. We kicked it off in the early spring and it didn't complete until August. Early on, the delays were unavoidable due to weather and ground conditions but after the foundation was in it took to long to complete the structure. The problem is not specifically the total time to complete but being left with very little time to replace the yard and driveway before winter."

Adam C on September 2018


Avatar for Tairi Construction

Tairi Construction

7032 W Greenfield Ave
5.00(
6
)
Approved Pro

Tairi Construction

7032 W Greenfield Ave
5.00(
6
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
768 local quotes requested

At Tairi Construction we stand with our customers. We strive to make your fantasies a reality, by specializing in all aspects of home remodeling. The services that we provide are: painting, hard wood and laminate flooring, complete kitchen and bathroom remodels, full Rec room remodel, tile work, and shower installs that will take as little as one day! For any and all inquiries please contact us at (414)376-7377

"Joe and his team were the first to respond after the Milwaukee floods happened in August 2025. Him and his team went above and beyond to clear out all of the debris in the basement, fully cleaned the basement, and applied mold remediation to the wooden beams. They also fully rebuilt our stairs and removed and replaced our egress window. Thank you so much Joe and team!"

James M on September 2025

At Tairi Construction we stand with our customers. We strive to make your fantasies a reality, by specializing in all aspects of home remodeling. The services that we provide are: painting, hard wood and laminate flooring, complete kitchen and bathroom remodels, full Rec room remodel, tile work, and shower installs that will take as little as one day! For any and all inquiries please contact us at (414)376-7377

"Joe and his team were the first to respond after the Milwaukee floods happened in August 2025. Him and his team went above and beyond to clear out all of the debris in the basement, fully cleaned the basement, and applied mold remediation to the wooden beams. They also fully rebuilt our stairs and removed and replaced our egress window. Thank you so much Joe and team!"

James M on September 2025


Avatar for JC BUILDERS INC

JC BUILDERS INC

P.O. Box 1038
4.64(
11
)
Approved Pro

JC BUILDERS INC

P.O. Box 1038
4.64(
11
)
Approved Pro
Customers say: Quality work
Recommended by 90% of Angi customers
Recommended by 90% of HomeAdvisor customers
35 local quotes requested

J C Builders is a Full service remodeling contractor providing services in south central Wisconsin since 1981.

"JC Builders do excellent work and are wonderful to work with! I highly recommend them for any remodeling, rebuilding projects. Prices are fair and workmanship and attention to detail are top notch. And, they know all the best plumbers and electricians in the business. They are my 'go to' guys whenever I need anything done around the house."

Vicky B on December 2018

J C Builders is a Full service remodeling contractor providing services in south central Wisconsin since 1981.

"JC Builders do excellent work and are wonderful to work with! I highly recommend them for any remodeling, rebuilding projects. Prices are fair and workmanship and attention to detail are top notch. And, they know all the best plumbers and electricians in the business. They are my 'go to' guys whenever I need anything done around the house."

Vicky B on December 2018


Avatar for Top Bros Construction & Remodeling Inc.

Top Bros Construction & Remodeling Inc.

1334 N Lake Shore Dr
4.88(
66
)
Approved Pro

Top Bros Construction & Remodeling Inc.

1334 N Lake Shore Dr
4.88(
66
)
Approved Pro
Customers say: Quality work
Recommended by 96% of Angi customers
Recommended by 96% of HomeAdvisor customers
1097 local quotes requested

Top Bros Construction & Remodeling Inc. is a family owned business by two brothers that love to create customers imaginations into realities. We as Top Bros Construction do all kind of interior remodeling in people's homes. From remodeling your bathrooms into master bathrooms or having the nicest kitchen you ever picture. We also install all hard surface floors starting from vinyl planks, laminate, vct tile, hardwood, engineer hardwood, ceramics. We refinishing and varnish hardwood floors as well as stairs and handrails. Were love to help our customers go thru the whole experience in a great matter of order and completion.

"⭐️⭐️⭐️⭐️⭐️ Absolutely Stunning Refinish – Highly Recommend! I couldn't be happier with the way our hardwood floors turned out! We had some old, torn-up floors that honestly looked like they were beyond saving—but the transformation is unbelievable. After the refinishing, they look like brand new floors, absolutely gorgeous, with a smooth, rich finish that completely elevates the look of our home. Not only was the quality of the work exceptional, but the price was also more than fair—especially considering the results. On top of that, they were incredibly professional: they showed up 15 minutes early, ready to work, and clearly take pride in what they do. It’s rare to find that kind of reliability and craftsmanship these days. If you're thinking about getting your hardwood floors redone, do it—and call these folks. I can't recommend them enough!"

shane m on July 2025

Top Bros Construction & Remodeling Inc. is a family owned business by two brothers that love to create customers imaginations into realities. We as Top Bros Construction do all kind of interior remodeling in people's homes. From remodeling your bathrooms into master bathrooms or having the nicest kitchen you ever picture. We also install all hard surface floors starting from vinyl planks, laminate, vct tile, hardwood, engineer hardwood, ceramics. We refinishing and varnish hardwood floors as well as stairs and handrails. Were love to help our customers go thru the whole experience in a great matter of order and completion.

"⭐️⭐️⭐️⭐️⭐️ Absolutely Stunning Refinish – Highly Recommend! I couldn't be happier with the way our hardwood floors turned out! We had some old, torn-up floors that honestly looked like they were beyond saving—but the transformation is unbelievable. After the refinishing, they look like brand new floors, absolutely gorgeous, with a smooth, rich finish that completely elevates the look of our home. Not only was the quality of the work exceptional, but the price was also more than fair—especially considering the results. On top of that, they were incredibly professional: they showed up 15 minutes early, ready to work, and clearly take pride in what they do. It’s rare to find that kind of reliability and craftsmanship these days. If you're thinking about getting your hardwood floors redone, do it—and call these folks. I can't recommend them enough!"

shane m on July 2025


MJ CONTRACTOR LLC

1800 Holborn Street
5.00(
1
)
Approved Pro

MJ CONTRACTOR LLC

1800 Holborn Street
5.00(
1
)
Approved Pro
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
2555 local quotes requested

Here to help you with all your home improvement needs you may have from remodeling, additions and more.

"Best company in the area, I recommend them to everyone ❤️‍🔥"

Kenneth G on December 2024

Here to help you with all your home improvement needs you may have from remodeling, additions and more.

"Best company in the area, I recommend them to everyone ❤️‍🔥"

Kenneth G on December 2024


Hannah Interiors

1185 Elm St
No reviews yet

Hannah Interiors

1185 Elm St
No reviews yet
22 years of experience

Hannah Interiors is a full-service design studio. We focus on your objectives, educate you throughout the process and help you make knowledgeable and confident design decisions. You will be able to enjoy the design process while we handle the details!

Hannah Interiors is a full-service design studio. We focus on your objectives, educate you throughout the process and help you make knowledgeable and confident design decisions. You will be able to enjoy the design process while we handle the details!

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FAQs for addition to existing structure building service projects in Watertown, WI

Yes, hidden rooms are legal, as long as they meet all local building regulations. If you sell your house, most states require homeowners to disclose full houseplans, which would include any hidden rooms.

If your secret room is a safe room, it should contain a means of communication aside from a cell phone, such as a shortwave radio. You should also have plenty of drinking water, a portable generator, emergency food supplies, blankets, pillows, flashlights, batteries and a first aid kit.

Any time you update your home’s square footage, you increase its value, but a secret room is a niche feature that doesn't rank high on every buyer’s list of must-haves. Investing your money in remodeling more common living areas like bedrooms, bathrooms, or kitchens will have a higher ROI than adding a secret room. Many secret rooms can act as entertainment spaces (think a game room or wine cellar) or quiet spaces (a library or study), so when building your secret room you may want to consider its versatility for when you’re ready to sell.

The Watertown, WI homeowners’ guide to addition to existing structure building services

From average costs to expert advice, get all the answers you need to get your job done.

  • A renovated kitchen with a waterfall island

    HomeAdvisor’s DIY Kitchen Remodel Cost Guide looks at the cost of buying supplies and doing the work yourself. Find the key cost factors and how to cut expenses.

  • Secret room within bookcase

    HomeAdvisor's expert guide walks you through the cost to build a secret room, whether you're creating a safe room for security or a fun space to fulfil your childhood fantasies. Use this guide to help plan your secret room project and explore room, concea

  • outdoor patio bar

    Explore the cost to build a bar in your home and learn how materials, wet vs. dry bars, and labor costs influence the total price of your project.