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Find Basement remodelers in Portsmouth

Avatar for NH Projects LLC
NH Projects LLC
5.0(
20
)

Serving Portsmouth, NH and surrounding areas

Approved

In business since 2021

Free estimates

Customers say: Quick response

"Lenny and Nick are great to work with! We are finishing our basement and they just completed the bathroom to start and it came out fantastic! They have excellent contacts to help with the plumbing and electricity and made the whole process easy for us. We can't wait to keep working with them and completing our basement."
Our Work
Our Work
Our Work
Our Work
Our Work

+8

Response time5 hrs
1 neighbors recently requested a quote
Recommended by84%of homeowners
Avatar for IDEAL SOLUTIONS LLC
IDEAL SOLUTIONS LLC
4.8(
13
)

Serving Portsmouth, NH and surrounding areas

Approved

In business since 2020

Free estimates

Credit card accepted

"I had an excellent experience with Ideal Solutions on my basement remodel. From start to finish, the team was professional, communicative, and detail-oriented. The quality of the work exceeded my expectations, and the finished basement turned out even better than I imagined. Everything was completed on time, and they made the entire process smooth and stress-free. I would absolutely recommend Ideal Solutions to anyone looking for basement remodeling or home improvement work."
3 neighbors recently requested a quote
Recommended by66%of homeowners
Avatar for Benchmark Home Improvements
Benchmark Home Improvements
4.8(
117
)

Serving Portsmouth, NH and surrounding areas

Approved

In business since 1997

Free estimates

Warranties offered

"We are so happy that we hired Benchmark to remodel our kitchen! Lee and Ian were professional and knowledgeable, from beginning to end. We were very impressed with their attention to detail. They made our 1980's dingy, dark kitchen look amazing with beautiful white cabinets and granite countertops. We love it! I highly recommend Benchmark and will recommend them to my family and friends. Thank you, Lee and Ian! Sallie and Don M."
Green Building ECO-CERTIF
Green Building ECO-CERTIF
Green Building ECO-CERTIF
Green Building ECO-CERTIF
Green Building ECO-CERTIF

+407

Response time2 days
6 neighbors recently requested a quote
Recommended by100%of homeowners
Avatar for The Hurlburt Group, LLC
The Hurlburt Group, LLC
4.4(
34
)

Serving Portsmouth, NH and surrounding areas

Approved

In business since 2007

Free estimates

Small jobs welcome

"Basement Finish Project: Dave Hurlburt and his team were amazing. They were quick but thorough and provided great customer service. Dave was flexible and wanted to provide the best service possible. Not to mention they provided a very fair price for the project. I would recommend this crew for any project."
basement subfloor
garage door
new beam header
garage door
closet

+77

Response time3 days
Response rate88%
14 neighbors recently requested a quote
Avatar for DCL Construction
DCL Construction
5.0(
9
)

Serving Portsmouth, NH and surrounding areas

Approved

In business since 2000

Free estimates

Emergency services offered

"We have been wanting to finish our basement for a very long time now but the prices we were given were too high! A friend of ours referred DCL to us and we thought we would give them a shot. The price was right so we started shortly after. They took care of all the paperwork and permits needed! Bob was there for the whole process discussing with us every step of the remodel! Very knowledgable and very well trained team! Our basement looks incredible and we enjoy spending time there! I would recommend DCL to anyone!!"
Completed jobs or on goin
Basement remodel
Basement remodel bathroom added
Basement remodel and bath room added
Basement remodel

+24

Response time6 hrs
1 neighbors recently requested a quote
Recommended by66%of homeowners
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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.