Is this your business?Claim this page →
Verified record
603 Contracting describes itself on HomeAdvisor as a general contractor based in Derry, NH, doing residential remodeling, additions and new home construction. It holds 5 stars from 17 HomeAdvisor ratings and 4 stars from 6 Google ratings. A 2026 customer said 603 rebuilt their basement after a flood, putting down new wood floors on a sleeper system, hanging drywall and painting. A 2026 customer said the company built a full bathroom in their lower level and a ramp in their garage for an ill husband. A 2026 customer who hired the company for an addition said the work was well organized, the timelines were realistic and the job site was kept clean and safe. A 2026 customer said Mike and his crew were on time every day during their kitchen remodel and gave them a great price. A 2025 customer said Mike completed their stairs in one day and his team was clean and respectful. A 2025 customer whose father-in-law had a heart attack said Mike arrived for snow removal within 2 hours. A 2025 Houzz reviewer said the team did a master bathroom and a full finished basement for them and finished fast and on time.
Mike was very professional, communicated clearly, and finished the job in a timely manner. Great experience overall.
We hired 603 Construction during Covid to build an addition on our home, and the result completely transformed how we live in the space, especially our kitchen, which has become the heart of our home and an incredible gathering place for family and friends. Like any major project (especially during Covid), there were challenges along the way, but Mike and team handled them and delivered a final product that has created lasting memories for my family and friends. Great group of guys that work hard to deliver! Highly recommend!!
I hired 603 contracting to finish my basement, they did a great job.
Top quality service at exceptional pricing, can’t say better things about Mike and his team at 603, they were great to work with!
They did a great job renovating my kitchen. I will hire them again for my next project.
Specializes in
Also offers
Service area
Languages
1 change recorded — last scanned Oct 31, 2026.
Typical New Hampshire range for this kind of work, from regional averages — not a quote from 603 CONTRACTING LLC. Use it to sanity-check bids, then get the real number in writing.
Estimated range
$20,200 – $30,800
Typical remodeling project around $25,500
