Top-rated addition to existing structure builders.

Get matched with top addition to existing structure builders in West Islip, NY

Enter your zip and get matched with up to 3 pros

Matching on HomeAdvisor

Share some details icon
Share some details about your home project.
Match with local pros icon
Within moments, match with highly-rated local pros.
Compare quotes icon
Compare quotes and choose the best pro for the job.

Find Addition to existing structure builders in West Islip

Avatar for BuildingLI.com - BLI Facilities LLC
BuildingLI.com - BLI Facilities LLC
5.0(
32
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

In business since 2017

Free estimates

Emergency services offered

"I hired Long Island handyman construction group to remodel a 400sf basement and bathroom in Melville. They were priced in the middle compared to other bids. I picked them thanks to their out of the box advice which saved me thousands of dollars. There was one problem with the plumbing which cost an extra 1800 dollars. The owner settled with me 50/50 even though it was a pre-existing issue. The project was started early and completed early. All mess was cleaned up and the crew was very friendly and fully aware. Very reputable guys and very easy to deal with. Thanks Moises and Eddy."
before demo
kitchen demolition
demolition complete
kitchen tile job in progress
kitchen tile

+172

Response time7 hrs
Recommended by76%of homeowners
Avatar for Arthur DeRosa Building and Remodeling
Arthur DeRosa Building and Remodeling
4.7(
13
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

In business since 1986

Free estimates

Customers say: True professional

"

This is the 2nd major project I contracted Art DeRosa & Co for.  The 1st being 4 years ago a major living room/family room renovation which was hugely successful.  That 1st experience led me to award Art (after several other competitive quotes) this 2nd and far larger & more complex project.







Overall it went well but this was a complicated project encompassing all the typical trades and expertise of building a new luxury house but far more complicated because it was a renovation performed while we were living in the home. Dust partition walls with wood framing had to be erected in several locations in the house which included temporary doors for entering and egress in certain areas of the remaining living areas of the house in order to protect the remaining house from dust and demolition , as well as, provide privacy for us during construction. 

Experience, Experience, Experience and Professionalism, Professionalism, Professionalism are the hallmarks of Art DeRosa and company.  He is a seasoned performer and pretty much seen it all.  Art has such a vast amount of home construction experience in both hi-end and medium end homes that he can draw upon a wealth of knowledge in all construction disciplines to implement a fine finished result.  As a former tool and die maker his penchant for hi-precision finish work yields highest quality appearances to things like moldings; trim; windows; doors; floors; etc. etc. 

This complex renovation project lasted 7 months which was within the initial time estimate given at the beginning and Art DeRosa and team were here every single day, day in and day out,  bright and early during that time frame. He did not start any other projects and stayed on the job day-in and day-out even when other sub-contractors such as plumbers and electricians were on the job site excluding his people from doing any other work. Art DeRosa and team were here every single day until final signoff.

I would not hesitate to recommend Art DeRosa & Co for any planned New House and/or House Renovation of any kind.


"
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+20

Response time2 days
5 neighbors recently requested a quote
Recommended by100%of homeowners
Avatar for All Island Additions and Renovations
All Island Additions and Renovations
5.0(
20
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

In business since 2025

Free estimates

Warranties offered

"All In One Comfort Solutions has been great to work with. They take their time, approach the issues correctly, and provide great value. I contacted them after feeling uncomfortable with a prior assessment from another company, which turned out to be a great decision. Highly recommended."
Before
After
Kitchen remodel
Bathroom remodel
Bathroom remodel

+71

Response time1 day
Response rate100%
Recommended by81%of homeowners
Avatar for Alta Renovations Corp
Alta Renovations Corp
5.0(
30
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

Super Service Award Winner

In business since 2019

Free estimates

Warranties offered

"Jose and his crew did an outstanding job on our extensive interior and exterior renovation, which included a new addition. The project covered everything from a new structural roof with shingles and skylights to new construction windows and doors, siding, a Trex deck, and fully renovated kitchen, bathroom, and laundry room. They also refinished a bedroom and installed beautiful hardwood floors. As with any large project, a few unexpected challenges came up, but Jose handled them with professionalism and kept everything moving forward smoothly. His craftsmanship is excellent, and he’s not only easy to work with but also patient and highly skilled at problem-solving. I wouldn’t hesitate to hire Jose again for future projects and highly recommend him to anyone looking for quality work and a reliable contractor."
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+26

Response time8 hrs
20 neighbors recently requested a quote
Recommended by80%of homeowners
Avatar for Homes & Beyond, Inc.
Homes & Beyond, Inc.
4.8(
20
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

In business since 2008

Free estimates

Emergency services offered

"Highly highly recommend Homes & Beyond….Miguel is a true professional from start to finish, communication was at 100% all the way throughout the project, I’ll be hiring them for other projects I have….and cannot say enough about his crew, polite, knowledgeable and kept my home so clean after every day til end of project!!!….they totally exceeded my expectations!!!!"
Kitchen
Kitchen
Kitchen
Kitchen open layout
Kitchen open layout

+50

Response time6 hrs
Response rate100%
2 neighbors recently requested a quote
Classic Home Design & Construction, LLC
5.0(
9
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

In business since 2015

Free estimates

Emergency services offered

"cannot recommend this company enough. They very graciously took on my very difficult project after another contractor resigned. I am beyond happy with the result. I know that with this company that the job has been done properly. Robert was able to communicate exactly what was being done, when, and why. The communication was unmatched. I will actually miss their excellent communication, the job was done in a timely manner. More was completed with this company in 2 weeks than 10 months with my previous contractor. Robert was kind and hardworking. I have only positive things to say about Classic Home Design and Construction LLC and I will happily use them again in the future, and I am thankful I was put in touch with such an upstanding company and people behind it."
Westbury 2021 Bath
Westbury 2021 Bath
Westbury 2021 Bath
Westbury reverse Gable remodel
Westbury 2021 Backyard

+38

Response time10 hrs
Response rate91%
4 neighbors recently requested a quote
Avatar for Cocos Custom Building LLC
Cocos Custom Building LLC
4.8(
9
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

Super Service Award Winner

In business since 2023

Free estimates

Warranties offered

"Cocos was very reliable. Answered my messages/calls in a timely manner. Showed up on time, did good work. Very clean. I would definitely use them again and recommend them to my friends and family."
Exterior Remodel
Modular Set And Exterior Finish Project
Exterior Remodel
Modular Set And Exterior Finish Project
Exterior Remodel

+31

Response time12 hrs
Response rate100%
14 neighbors recently requested a quote
Avatar for A.S.M. Home Improvements
A.S.M. Home Improvements
5.0(
12
)
Addition to Existing Structure - Build

Serving West Islip, NY and surrounding areas

Approved

In business since 2021

Free estimates

Credit card accepted

"We cannot say enough about ASM Home Improvement. The owner Anthony was absolutely amazing every step of the way. First he put our mind at ease to what we wanted was not only possible but was going to be great and great it was ! Him and his crew were professional and sincerely cared about the job. The workmanship was top notch. Anthony’s talent to make our deck beautiful truly showed and we absolutely love it ! We will hire Anthony and his crew again for our next project and highly recommend him and his company. He will make your vision a reality!"
Remodeling
Remodeling
Remodeling
Remodeling
2 of 2
fire pit

+48

Response time11 hrs
14 neighbors recently requested a quote
Recommended by58%of homeowners
...
Showing 1-10 of 598
FAQs for addition to existing structure building service projects in West Islip, NY

You can typically raise your roof by four to eight feet, depending on your home's structure and roof design. The exact amount depends on factors like roof slope and framing support. Raising the roof creates additional interior space, enhances natural light, and increases your home's value. Consult a professional to determine the feasible height increase for your home.

Yes, you need a building permit to raise your roof. Obtaining a building permit ensures your project complies with local building codes and safety regulations. A professional contractor can assist with the permit and inspection process and ensure all legal and safety requirements are met. Your contractor will be familiar with building codes in your area, which can differ between cities or states.

While it's possible to raise a flat roof, it requires extensive structural modifications. Flat roofs lack the attic space and support structures of pitched roofs, so raising them involves significant engineering to ensure safety and durability. This process can be complex and costly, so professional assessment is essential before undertaking a project of this magnitude.

The West Islip, NY 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.