Top-rated basement remodelers.

Get matched with top basement remodelers in Portsmouth, NH

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 Basement remodelers in Portsmouth

Avatar for Pro Warrior Construction
Pro Warrior Construction
5.0(
29
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2018

Free estimates

Emergency services offered

"Pro Warrior is one of the last few business run with ethics and character. Fast, reliable work you can depend on. These are the guys that get the job done without any trouble. I’d hire them again and again! "
Matt Klein
Matt Klein
Matt Klein
Response time4 days
6 neighbors recently requested a quote
Recommended by79%of homeowners
Avatar for MMP Construction Inc
MMP Construction Inc
4.7(
191
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2004

Free estimates

Emergency services offered

"We needed a skylight installed in our bathroom, and MMP did an excellent job--we are very happy with it! The team was friendly and worked quickly and efficiently to get it done before it got dark, and the quality of their work was excellent. Matt was very friendly and nice to communicate with as well, and always responded right away. I highly recommend MMP Construction to anyone looking for great quality work and excellent customer service."
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+154

1 neighbors recently requested a quote
Recommended by89%of homeowners
Avatar for NH Projects LLC
NH Projects LLC
5.0(
19
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2021

Free estimates

Customers say: Quick response

"Because we were going away for an extended time, and insulation work by others had to be completed first, we had to schedule drywall workday NH Projects under a rather tight time frame. Despite uncooperative weather (lots of rain slowing the drying time), they managed to get everything done as needed, working around other scheduled work they had. They were prompt, professional, and a pleasure to interact with, in addition to doing excellent work."
Our Work
Our Work
Our Work
Our Work
Our Work

+8

Response time5 hrs
2 neighbors recently requested a quote
Recommended by84%of homeowners
Avatar for Owens Corning Basement Finishing System
Owens Corning Basement Finishing System
4.8(
343
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

Super Service Award Winner

In business since 1990

Free estimates

Credit card accepted

"I recently completed an approximately 800 sq. ft. basement renovation with Owens Corning/Lux Renovations, including a full bath and wet bar, and the experience was excellent from start to finish. The project began earlier than expected, stayed on schedule, and was completed beautifully in five uninterrupted weeks. Our project manager, David Guimaraes, was professional and always accessible by phone or text, and onsite weekly, while onsite supervisor Alvaro was present daily and consistently went above and beyond to ensure our satisfaction—including adjusting a wall so a large piece of furniture would fit perfectly. The materials were high quality, and I appreciated the flexibility to substitute my own fixtures, with changes made seamlessly and without issue. I love my basement!!! If you are interested in doing a basement renovation, I would highly recommend this company. Basement renovations are their business and they are great at it. "
Media Room Before
Media Room After
Games Room Before
Games Room After
Living Room Before

+81

Response time11 hrs
268 neighbors recently requested a quote
Recommended by77%of homeowners
Avatar for Boyd Building
Boyd Building
5.0(
17
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2001

Free estimates

Emergency services offered

"We bought our first home this year and absolutely love it, but we quickly learned it needed more TLC than we realized. We could see rot on our exterior trim and clapboards, plus a missing gable vent. From the very beginning, Shawn impressed us. His estimate was incredibly thorough, and it was clear he’s a true professional. As new homeowners, we felt confident putting our home in his hands. We are so fortunate we hired him. Shawn showed up early, worked late, and demonstrated meticulous attention to detail in everything he did. When we discovered the rot was far more extensive than we thought, he never made us feel stressed or overwhelmed—he walked us through our options, offered solutions, and helped us make the right decisions for our home. The quality of his work speaks for itself, but just as important, his communication, reliability, and integrity made the experience exceptional. We will be working with Shawn for all of our home’s needs. We actually missed him when he left ! "
Stone veneer
Stone veneer
Stone veneer
Stone veneer
Stone veneer

+80

Response time2 hrs
5 neighbors recently requested a quote
Recommended by70%of homeowners
Avatar for True North Contracting
True North Contracting
4.8(
82
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2005

Free estimates

Small jobs welcome

"Costas was amazing. Very transparent and his workmanship is top notch. Throughout the project he kept us on the loop and walked us through step by step what his plan was. "
Roof
Kitchen Reno
Finish
Ready for Grout
 Finished

+66

Response time4 hrs
10 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for IDEAL SOLUTIONS LLC
IDEAL SOLUTIONS LLC
4.8(
12
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2020

Free estimates

Credit card accepted

"They are very good at what they do. We re-hired them after they did a job for us over last summer. There were differences on a this second job. If you use this company, I recommend: 1. Insist on a thorough, detailed contract that specifies ALL the details. Several things were forgotten, and later treated as ;added and as scope change. Could have been avoided with cleaner communication. 2. Specify in writing whether or not sub-contractors will be used for the job. During this second job, we had a couple of sub-contractors that were really, really bad. a. If sub-contractors are used, recommend specifying that a crew chief from Ideal be on site at ALL times. If needed, they should provide translation services. Our place was trashed when they left the site; sheet rock dust everywhere, floors to scrape, a hole in the wall to fix, lots of hard work ahead. They knocked off $2K. I would not do this amount for $2K. Bottom line, do not feel it was an fair solution. Learned a lesson."
Recommended by66%of homeowners
Avatar for Magic Frog Carpentry & Woodworks
Magic Frog Carpentry & Woodworks
5.0(
10
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

Super Service Award Winner

In business since 2015

Free estimates

Warranties offered

"Adam, the owner of Magic Frog Carpentry & Woodworks is great to work with. He is responsive via text and phone conversations. He has a lot of skilled people he works with and does a lot of the work as well. When any hiccup comes up he is quick to get it resolved. This past fall I hired him to do a partial remodel of my kitchen (new countertop, new backsplash, new flooring and painting. I was happy with the work and decided to hire Adam again for a tub to shower conversion. I am really happy with the results of both projects. I plan on reaching out to Adam for the next home project. "
High Ceilings. Inside 45 degree angles done with NO-Coat 450
Tall Foyer. Wrapped beam. Unfinished at post.
Outside corners with bead. Outside 45 degree angles with No-Coat 450.
Deep Skylights with drywall returns.
Before

+11

Response time2 days
Response rate91%
27 neighbors recently requested a quote
Avatar for DCL Construction
DCL Construction
5.0(
8
)

Serving Portsmouth, NH and surrounding areas

Angi Approved

In business since 2000

Free estimates

Emergency services offered

"We needed a floor to ceiling curtain on an overhead track separation at bottom of stairs. Bob did the work efficiently and within our timeframe.. Also when we added installation of 3 disability bars, this was done to our complete satisfaction. Thank you, Very happy with results!"
Completed jobs or on goin
Basement remodel
Basement remodel bathroom added
Basement remodel and bath room added
Basement remodel

+24

Response time6 hrs
14 neighbors recently requested a quote
Recommended by75%of homeowners
...
Showing 1-10 of 262
FAQs for basement remodeling projects in Portsmouth, NH

Finishing a basement turns unused square footage into livable space and returns up to 70% of what you spend when you sell your home. Beyond that resale boost, you gain a playroom, home office, or guest suite you can start enjoying right away. That mix of daily comfort and solid return on investment (ROI) makes basement finishing one of the smartest upgrades you can tackle.

In some parts of the country—especially lots on swamps, high water tables, or other wetlands—local codes prohibit basements. Saturated soil puts constant pressure on foundation walls and lets water seep in faster than any sump pump can handle. 

If your property sits on waterlogged ground, building on a slab or crawl space is often safer, more affordable, and code-compliant.

Most basements wrap up in four to eight weeks. Framing takes three to five days, with electrical and plumbing rough-ins following over the next week. Add five days for drywall, two to three for flooring, and another week for paint, trim, and punch-list items. 

Delays can happen if materials run late or your contractor’s calendar is packed, so build in a little cushion when you plan.

Whether a finished basement counts toward your home’s official square footage depends on local rules. Many areas only include below-grade space if it has code-approved egress, fully finished walls, ceilings, and floors, plus consistent heating. 

Check with your local assessor or building department before you start; meeting those standards can affect taxes, appraisals, and resale value.

Building codes require a checklist: dedicated heat and electrical service, a code-approved stairway, and at least one egress window or exterior door. Walls, ceilings, and floors must be fully finished and meet insulation, ventilation, and fire-separation standards. If you add a bedroom, you’ll also need a closet, proper clearances, and safe exits. If you change the layout later, be ready to update the space so every new room still meets today’s code.

The Portsmouth, NH homeowners’ guide to basement remodelings

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