One Call. Every Fix. Done Right.
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Call us now and we'll work to schedule a technician the same day, across every trade we handle.

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HVAC, Electrical, Plumbing, & Home Modification Services in Londonderry

Residential & Commercial Help, One Call Away

Our team at Cornerstone Services treats your home as more than just a building, because it's where life happens, and it deserves to be cared for by a company you can genuinely trust. Local home and business owners rely on us for a comprehensive range of services, including HVAC, electrical, plumbing, home modifications, cleaning, handyman, and senior living construction. Whatever your home requires today or in the years ahead, we bring the experience, skill, and dedication to get it done right.

Our tagline is One Call Does It All and we mean it. All work is handled by the same team, under the same warranty and pricing structure. You don’t manage multiple contractors; you make one call.

Ready to schedule your services in Londonderry? Call us now at (603) 874-1402. Same-day appointments are available, and our team is on call around the clock.

Complete Home Solutions Under One Roof

Managing your home shouldn't mean managing a long list of different contractors. We've built our team to handle the full spectrum of services local homeowners need, so you always have one reliable place to turn. 

Our HVAC technicians keep your heating and cooling systems performing at their best through every New Hampshire season, from the coldest February nights to the most humid summer days. We install, repair, and maintain the full range of systems southern NH homes and businesses rely on.

Our HVAC services include:

Our licensed electricians tackle everything from minor repairs and fixture installations to major panel upgrades and full rewiring projects, while our experienced plumbers handle leaks, clogs, water heater replacements, and full pipe installations with efficiency and precision. When every service comes from the same trusted team, you spend less time coordinating and more time enjoying a home that works the way it should.

Home Modifications Built for the Way You Live

A home that fits your life perfectly doesn't happen by accident — it takes thoughtful planning and skilled execution. Our home modification services are designed to help homeowners adapt their spaces to meet changing needs, whether that means improving accessibility, reconfiguring a layout for better function, or making updates that simply make daily life more comfortable. 

We take the time to understand what you're looking for and bring the craftsmanship to deliver results that are practical, durable, and tailored specifically to your home. From structural adjustments to custom upgrades, we handle every aspect of the project so the end result exceeds your expectations.

The Value of One Trusted Team

Choosing Cornerstone Services means more than getting individual jobs done well; it means having a team that understands your home as a whole. When we handle your services, we build a comprehensive picture of how your home is put together and what it needs to stay in excellent condition. That familiarity allows us to identify issues across systems before they escalate, plan projects more efficiently, and provide guidance that reflects the full context of your home rather than just one isolated corner of it. 

For local property owners, that translates to smarter decisions, fewer unexpected costs, and a level of confidence that comes from working with people who truly know their home.

Why Londonderry Customers Choose Cornerstone Services

More than 1,250 five-star reviews across Google, HomeAdvisor, Facebook, and Yelp reflect a track record built job by job. Here’s what drives that reputation:

  • Per-Job Flat Pricing: We price by the job, not the hour. The number we quote you is the number you pay at completion: no adjustments, no hourly overruns, no hidden fees.
  • Signed Workmanship Warranty: Every completed job is backed by a signed warranty under our quality assurance policy. You get documented protection on our work, not just a verbal promise.
  • On-Time Arrival: Our service vehicles are staged from multiple locations, and our scheduling system is built specifically to support on-time arrival.
  • Same-Day Service Available: Call us, and we’ll work to get someone out the same day for urgent HVAC needs.
  • Background-Checked Workers: Every technician sent to your property has passed a background check before arrival.
  • 24/7 On-Call Staff: Our team is available around the clock for scheduling, questions, or urgent needs.

We also offer financing options for larger projects. Ask about current terms when you schedule. Monthly promotions rotate throughout the year and can bring additional savings on scheduled services.

A Long-Term Partner for Your Property

Cornerstone Services is proud to serve the community with the kind of honest, dependable care that homeowners deserve. Our reputation is built on quality workmanship, clear communication, and a steadfast commitment to standing behind every job we complete. Whether you're addressing an immediate repair, planning a home modification, or beginning a senior living construction project, we're here to guide you through every step of the process with professionalism and genuine care. 

The Price We Quote is the price you pay at completion, every time.

No hourly overruns, no hidden fees. Every job is backed by a signed workmanship warranty.

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1,250+ Five-Star Reviews & Counting

We let our work speak for itself. From quick repairs to major installs, our customers say it best.
5
Based on 1,250+ reviews
    "Paul was by far the best one"
    Paul Quinn did electrical work for me and he was the best!
    Nicola Sullivan
    "Excellent to work with"
    Michael with Cornerstone Services was excellent to work with.
    Jamie Fasbender
    "He was very professional"
    He was very professional and explained all that he was doing.
    Mary Duford
    "A job well done!"
    Showed up as agreed and was very informative.
    John Cote
    "Fast response and very professional"
    Fast response and very professional.
    Anne Butterworth
    "Entire AC Unit Redone"
    On time. Thorough. Kind. Positive attitude in this awful heat.
    N N
    "I couldn’t be happier"
    Cornerstone came promptly and fixed them.
    Marilyn Frank
    "Overall, a Great Experience"
    He and his partner PJ worked quickly and efficiently to solve a dryer vent issue we had been experiencing.
    Pierre Thelusma
    "Excellent Service, Very Cordial"
    Took care of our electrical needs with ease!
    Peter Larocque
    "Paul from Cornerstone was fantastic!"
    He was quick, thorough, professional, and made sure everything was done right.
    Jess Nichol
    "Nothing but a wonderful experience"
    10/10 experience and so happy we got in touch with him and this company!
    Anthony Capozzi
    "Did an Excellent Job Finding a Leak"
    They were so neat, you would never know there was a problem.
    Bill Mullen
    "Paul is always friendly, polite, and professional"
    Paul is always friendly, polite, and professional.
    Cindy Marcin
    "All Went Smoothly and Efficiently"
    Paul was efficient and expert at correcting the problem and ensuring all was well.
    Woodrow Cook
    "Robert Did Fantastic Work"
    He went above and beyond for me when some unforeseen issues arose with my bathtub install.
    Susan Hevey
    "New customer"
    Tech was on time, friendly, and competent.
    Vincent JJ Balukonis
    "Jason did a fantastic job"
    He was very thorough and quickly corrected the issue.
    Gary Chisholm
    "Very Prompt and Clear Service"
    Josh was very prompt with his services and explained things clearly.
    Kim Mcanany
    "Great job, appreciate the care"
    Arnold is a pleasure to work with.
    Esther Bradbury
    "Jason is always great and knowledgeable"
    Jason is always great and knowledgeable and friendly.
    Mark Duell
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Questions We Hear Before Every Job

Do you charge by the hour?
No. Every job is priced by the job, not the hour. We give you a flat rate before the work begins, and that number doesn't change at completion, regardless of how long it takes.
What trades do you handle?
We cover HVAC, plumbing, electrical, cleaning, handyman work, and home modifications, including wheelchair ramp installation, grab bar installation, and stairlift installation. Every trade is handled by the same company under one warranty.
Is same-day service available?
Yes. Call us and we'll work to get a technician out the same day. Our staff is on-call 24 hours a day, every day of the week.
Are your workers background-checked?
Yes. Every worker we send to your property has passed a background check before setting foot in your home or business.
Do jobs come with a warranty?
Yes. Every completed job is backed by a signed warranty under our quality assurance policy. You get documented protection on the work, regardless of which trade performed it.
Do you serve commercial customers?
We do. We handle both residential and commercial work across every trade, with the same per-job pricing and signed warranty for business customers.

YOUR HOME
DESERVES THE BEST

Let's Make It Happen!
  • On-Call 24/7
  • One Company. Every Trade.
  • 1000s of Happy Customers
  • Your Neighbors Since 2003
Prefer to Call? Our staff is available around the clock.

Reach us any time to book a service, ask a question, or get on the same-day schedule.

Call (603) 874-1402
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