your Dream outdoor living space

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Improve your lifestyle
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Host Great Parties
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Increase Your Home Value

Deck Builder in Geneva, NY

Make your dream outdoor living space a reality with a custom deck and additional features!

“We are incredibly pleased

with the outcome and excited to have this new outdoor living space to relax and spend time with the family.”

- Garret Pachtinger

 “The most professional

and understanding crew I've ever had the pleasure to be able to have work done for my family.”

- Guiseppe Troisi

“We LOVE our new deck

with an outdoor kitchen and fireplace!”

- Megan & Dave Johnson

“Dream come true.

We are over the moon happy with our new deck.”

- Angela R.

Become a Master Host in Geneva with a custom outdoor deck and living space.

  • Group Of Happy Young Friends Having Dinner At Patio

    Host Great

    Make new and lasting memories with family and friends.

  • Home lifestyle woman relaxing enjoying luxury sofa patio furniture on outdoor patio

    Have a Place
    to Relax

    Let life’s worries behind as you enjoy the beauty of the outdoors.

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    Be Proud
    of Your Space

     Become the envy of the neighborhood with your beautiful outdoor space.

Download our catalog to see everything we offer with our custom decks!

At Keystone Custom Decks, we believe having your dream outdoor living space designed and built should be an enjoyable and painless process.

  • Do you love hosting people, but you don’t love your available space?

  • Do you enjoy spending time outdoors, but your existing outdoor space is unattractive or unusable?

  • Do you have a vision for your dream outdoor living space, but you feel overwhelmed by the construction process?

We know what it feels like to not love your outdoor living space. That is why we have been building custom decks for over 30 years.

“Incredibly skilled and detailed workmanship!  Mahlon and his crew did an amazing job minimizing disturbance on our difficult, steep back yard.
The deck is gorgeous and we couldn't be happier with our choice of Keystone Custom Decks."
-Bren Bunny

We make the process as easy as possible

  • 1

    Call Us

    We’ll learn more about your space and schedule an estimate.

  • 2

    Design Proposal

    Receive your quote and complimentary 3D rendering.

  • 3


    Sign your proposal and watch your dreams become reality.

  • 4


    Love your new deck and space you have to host parties and live!

3D Render Final Build
“Their 3D rendering really helped us envision what the final project would look like, and it helped guide us in making adjustments and changes to improve the functionality of the living space.”
- Lawrence Han

What you can expect with Keystone Custom Decks:

Turn-key Projects

We take care of every part of the construction process.

Lifetime Workmanship Warranty

We stand behind our work for life.


We deliver on our timeframe and proposal promises.

Financing Available

We offer financing options through our partners.

"Keystone built our deck in Summer of 2015.  The crew was extremely hard working and polite.  Overall, we are very pleased with our deck and we receive compliments on it all the time.  Keystone made our idea a reality."

- Amanda Russo

"We are happy with all aspects of our experience building a deck with Keystone.  The contract defined exactly what we wanted, and the finished product met all the specs.  We're enjoying our new deck!"

- Carol Poole

"My entire experience with Keystone was five star.  Every aspect of this transaction was conducted with professionalism.  I wouldn't hesitate to recommend Keystone to anyone."

- Lyn Strickler

Custom Deck Builder in
Geneva, NY

If you own a home in Geneva or along Seneca Lake, you want a beautiful outdoor living space.  The problem is your current outdoor space might be unattractive or unused.  Keystone Custom Decks builds beautiful custom decks and outdoor living spaces so you can host great parties, make memories, and improve your lifestyle.
At Keystone Custom Decks, we know you want to create and live in your dream outdoor living space, and that is why we have been building custom decks for over 30 years.

We are a custom deck builder in Geneva, NY.  We serve all homes in the City of Geneva, along Seneca Lake, and the surrounding areas.

If you live in Geneva or nearby, you know how much there is to do in the city and along the lake.  After spending a day exploring downtown Geneva, enjoying nature and the breezes of Seneca Lake, or watching the kids splash and play at Seneca Lake State Park; come home to your dream outdoor space to relax and unwind! 

Geneva, NY has a lot to offer both residents and guests! Attractions include: 

  • Seneca Lake State Park
  • Rose Hill Mansion
  • Ravines Wine Cellars
  • Three Brothers Wineries and Estates
  • Belhurst Castle
  • Smith Opera House
  • Geneva Gelato
  • Halsey's Restaurant
  • F.L.X. Table
  • Geneva Farmers Market
  • and so much more!

The City of Geneva was originally home to the Seneca tribe who established a major village in the area. During the Seven Years' War, the British helped the Seneca fortify this village against the Canadian French. They did this again during the Revolutionary War. Settlers moved to the area in the late 1700s. Geneva was incorporated in 1806 and became a city in 1871. It is differentiated from the Town of Geneva which borders it. 

We are happy to serve Geneva, NY, zip code 14456, and the surrounding areas. 

Pat:  What can I say... QUALITY & SERVICE! This is the second deck we've had built with Mahlon and Keystone Custom Decks, and we're even happier this time around.

To see what they've grown into is Amazing, but not so surprising. When you love what you do, and you genuinely like to take care of people, being successful is a by-product!

The experience is wonderful! Mahlon really hears you in the consultation, what you like, what you want, and what you need... he always hits the goal of making you happy and meeting the budget. 

Then come Anthony and the guys! WOW! They are AMAZING! The "on the job" communication and teamwork is superb.

From the moment they arrive each day until they leave, their focus and goal are to "deliver the promise" that Maholn makes when you first sign. There's no crazy stuff either, no cursing, no cigarette butts to pick up, my wife even said she definitely felt safe and comfortable with the guys working here (we've had other experiences).

Just all in all, this is a great company that does great quality work! God Bless Keystone Custom Decks!

Ed & Claudine: We cannot praise Keystone Custom Decks enough. The whole process was seamless. Mahlon took our vision and made it reality. The entire crew was exceptional. They were so professional, hard working and meticulous with everything from big decisions to the smallest details. We would highly recommend them and would definitely hire them again for any future projects. 

John: We are absolutely thrilled with the front and back decks that Keystone built for us! From the design process with Mahlon to the crews who worked tirelessly each day to complete the process, Keystone is definitely a professional and skilled contractor. They answered any question or concern we had as the project progressed and the finished product is just beautiful! I would recommend Keystone above all others without hesitation.

Geneva Deck Builder

To make your dream backyard a reality, we also know that you may want more than just a deck.  That is why we offer more than just custom decks in Geneva.

We also offer the following:

All these features will make your backyard dreams come true and make you a master host!