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Addition to existing structure builders in Sun Prairie

Avatar for LP Customs, LLC
LP Customs, LLC
3717 Token Road
5.00(
8
)
Approved Pro
LP Customs, LLC
3717 Token Road
5.00(
8
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
11 local quotes requested

At LP Customs, we build custom homes, log homes, major remodels like addtions, basements, bath and kitchen remodels. Since we are a smaller business, we are able to provide our clients with a more affordable price. We do all phases of construction. Clients really like the idea of one crew in their homes versus many subcontractors. We can provide many references to prove that our quality speaks for itself. Give us a chance to bid your next project, you will be glad you did. Please call us at 1-608-575-8338. You can also review our work on LP Customs, llc facebook page! Check out the album section. Website is down for reconstruction.

"Very easy to work with, did an excellent job, and stayed within budget. This was a custom, unusual garage."

Laurenc T on October 2019

At LP Customs, we build custom homes, log homes, major remodels like addtions, basements, bath and kitchen remodels. Since we are a smaller business, we are able to provide our clients with a more affordable price. We do all phases of construction. Clients really like the idea of one crew in their homes versus many subcontractors. We can provide many references to prove that our quality speaks for itself. Give us a chance to bid your next project, you will be glad you did. Please call us at 1-608-575-8338. You can also review our work on LP Customs, llc facebook page! Check out the album section. Website is down for reconstruction.

"Very easy to work with, did an excellent job, and stayed within budget. This was a custom, unusual garage."

Laurenc T on October 2019


Avatar for Alpha Building & Design, LLC
Alpha Building & Design, LLC
N7492 COUNTY RD N
5.00(
5
)
Approved Pro
Alpha Building & Design, LLC
N7492 COUNTY RD N
5.00(
5
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
15 local quotes requested

With over 10 years of experience the contracting industry, we are the experts you need to take care of your home or business. We handle everything from remodeling to deck replacements. We will treat your home as we would treat our own. Give Alpha Building & Design LLC a call today, we look forward to working with you!

"Abner and the team were awesome to work with for finishing our basement. Super knowledgeable and provided great recommendations. They exceeded my expectations by far. Very appreciative of their stellar work."

Alyssa P on February 2022

With over 10 years of experience the contracting industry, we are the experts you need to take care of your home or business. We handle everything from remodeling to deck replacements. We will treat your home as we would treat our own. Give Alpha Building & Design LLC a call today, we look forward to working with you!

"Abner and the team were awesome to work with for finishing our basement. Super knowledgeable and provided great recommendations. They exceeded my expectations by far. Very appreciative of their stellar work."

Alyssa P on February 2022


Avatar for Clearview Sunrooms & Windows
Clearview Sunrooms & Windows
2227 S Stoughton Rd
4.43(
14
)
Approved Pro
Clearview Sunrooms & Windows
2227 S Stoughton Rd
4.43(
14
)
Approved Pro
Customers say: Super punctual
149 local quotes requested
25 years of experience

Locally owned and operated home improvement company by Ben Kripps. ClearView's showroom is located in Madison. Showroom is open for browsing during normal business hours. Pricing is done by showroom or home appointments only at anytime with Ben Kripps.

Locally owned and operated home improvement company by Ben Kripps. ClearView's showroom is located in Madison. Showroom is open for browsing during normal business hours. Pricing is done by showroom or home appointments only at anytime with Ben Kripps.


Avatar for Matrix Basement Finishing
Matrix Basement Finishing
3050 N Kennicott Ave
4.55(
272
)
Approved Pro
Matrix Basement Finishing
3050 N Kennicott Ave
4.55(
272
)
Approved Pro
Customers say: Quality work
312 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.

"Efficient scheduling on builder trend! They did an awesome job cleaning up after themselves too! Ask to work with Ben as your project manager!"

Lana G on June 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.

"Efficient scheduling on builder trend! They did an awesome job cleaning up after themselves too! Ask to work with Ben as your project manager!"

Lana G on June 2025


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
42 local quotes requested

Ready to finish your basement? We care enough to do it right the first time. Our family owned company has been serving homeowners like you since 2001. We are a BASEMENT FINISHING specialist. Granzow Home Improvement, LLC is well known in the home improvement & remodeling industry, as a client-focused company that strives to ensure the highest levels of quality and customer satisfaction. We have a A+ BBB Rating. You will love our "no pressure" approach, FREE design assistance that comes with nearly 23 years of experience, professionally prepared plans, detail oriented proposals that come with a written guarantee for price accuracy, and our comprehensive written warranty that backs all services we provide. 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? We care enough to do it right the first time. Our family owned company has been serving homeowners like you since 2001. We are a BASEMENT FINISHING specialist. Granzow Home Improvement, LLC is well known in the home improvement & remodeling industry, as a client-focused company that strives to ensure the highest levels of quality and customer satisfaction. We have a A+ BBB Rating. You will love our "no pressure" approach, FREE design assistance that comes with nearly 23 years of experience, professionally prepared plans, detail oriented proposals that come with a written guarantee for price accuracy, and our comprehensive written warranty that backs all services we provide. 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 Complete Handyman
Complete Handyman
2317 Mica Rd.
4.77(
26
)
Approved Pro
Complete Handyman
2317 Mica Rd.
4.77(
26
)
Approved Pro
Customers say: Quality work
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
27 local quotes requested

My name is Mark Schwebach. I am the owner of Complete Handyman as a division of Dream Homes LLC. I founded the company in 2004. I am 100% involved with day to day activities. I specialize in finishing basements. When it comes to basements, I will be involved in every aspect of the job. I will be hands on from the initial design process, the bidding process, acquiring permits, doing the actual construction, overseeing sub-contractors, through to the completion of the finished basement. I personally guarantee the highest level of attention to quality and detail throughout the entire project.

"Mark did an excellent job with finishing our basement, it turned out exactly how we wanted. What we liked most about Mark is that he is very trustworthy and honest. He is very open and transparent with all the costs . He also is very detailed and percise and his subcontractors were very good as well. We would highly reccomend Mark if you need to finish your basement!"

Jim Q on December 2024

My name is Mark Schwebach. I am the owner of Complete Handyman as a division of Dream Homes LLC. I founded the company in 2004. I am 100% involved with day to day activities. I specialize in finishing basements. When it comes to basements, I will be involved in every aspect of the job. I will be hands on from the initial design process, the bidding process, acquiring permits, doing the actual construction, overseeing sub-contractors, through to the completion of the finished basement. I personally guarantee the highest level of attention to quality and detail throughout the entire project.

"Mark did an excellent job with finishing our basement, it turned out exactly how we wanted. What we liked most about Mark is that he is very trustworthy and honest. He is very open and transparent with all the costs . He also is very detailed and percise and his subcontractors were very good as well. We would highly reccomend Mark if you need to finish your basement!"

Jim Q on December 2024


Avatar for Kool View Co.,Inc.
Kool View Co.,Inc.
1860 Bud Dr #104
New on HomeAdvisorNew on Angi
Approved Pro
Kool View Co.,Inc.
1860 Bud Dr #104
New on AngiNew on HomeAdvisor
Approved Pro
106 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 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
70 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 Keller Builders LLC
Keller Builders LLC
940 Hwy 51
4.17(
6
)
Approved Pro
Keller Builders LLC
940 Hwy 51
4.17(
6
)
Approved Pro
Customers say: Quality work
235 local quotes requested
Free onsite estimate

We have the experience and dedication to do the job right the first time! We guarantee your satisfaction, and we won’t leave until the job is done right. Call to schedule an estimate today! May contact through email.

"They completed several projects for me. I appreciated the careful attention to doing good work. Each time, I was pleased with the finished look and function."

karen k on March 2021

We have the experience and dedication to do the job right the first time! We guarantee your satisfaction, and we won’t leave until the job is done right. Call to schedule an estimate today! May contact through email.

"They completed several projects for me. I appreciated the careful attention to doing good work. Each time, I was pleased with the finished look and function."

karen k on March 2021


Avatar for Interiors by JW
Interiors by JW
603 West Main Street
New on HomeAdvisorNew on Angi
Approved Pro
Interiors by JW
603 West Main Street
New on AngiNew on HomeAdvisor
Approved Pro
27 years of experience
Free onsite estimate

At JW, we’ve been providing our customers with quality craftsmanship and innovative solutions since 1998. We’ve built our reputation on a solid foundation of integrity and trust, the cornerstones of our company’s values. Choosing to work with JW means you’re in good hands. We provide a 2-year warranty on all of our work, and you’ll receive manufacturer warranties on all the products we install. Our detailed estimating software ensures that you receive a fair quote that is accurate the first time and won’t escalate during the course of your project. We strictly adhere to all city and state requirements for licensing and insurance regulations, ensuring that we are compliant at all times. JW provides a full range of remodeling services including a full-time interior design team, to make your remodeling process as seamless as possible.

At JW, we’ve been providing our customers with quality craftsmanship and innovative solutions since 1998. We’ve built our reputation on a solid foundation of integrity and trust, the cornerstones of our company’s values. Choosing to work with JW means you’re in good hands. We provide a 2-year warranty on all of our work, and you’ll receive manufacturer warranties on all the products we install. Our detailed estimating software ensures that you receive a fair quote that is accurate the first time and won’t escalate during the course of your project. We strictly adhere to all city and state requirements for licensing and insurance regulations, ensuring that we are compliant at all times. JW provides a full range of remodeling services including a full-time interior design team, to make your remodeling process as seamless as possible.

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

Building an in-law suite takes between two and seven months. Converting an existing basement, attic, or room can be done in about two months. Constructing a new addition or detached suite often takes four to five months for construction, plus one to two months for permits. The bigger the suite, the longer it will take. 

Yes, you can build an in-law suite in your backyard if you meet local building codes and zoning regulations. An in-law suite often occupies 300 to 800 square feet. Be sure to follow size restrictions, utility separations, and entrance requirements. Hiring a qualified contractor ensures you meet all regulatory requirements because they can pull permits, double-check local code, and gather other skilled pros to work on your suite. 

An in-law suite is a self-contained living space attached to—or detached from—your main home. Expect a bedroom, full bath, and a kitchenette or compact living area. The setup gives relatives privacy, doubles as a potential rental, and can lift your property value. To qualify as a legal dwelling, the suite must meet local building codes and zoning rules.

The Sun Prairie, 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.
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Looking to enhance the warmth and utility of your kitchen? Explore how much a butcher block countertop costs and start your budget here.
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Budget for outdoor kitchen costs based on factors such as appliances, materials, permits, labor, amenities, kitchen size, customizations, and more.
BLUE TWO STORY HOME
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Budget for the cost to add a second story based on factors such as size, foundation work, materials, labor, permits, post-construction cleaning, and more.
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