Can I Change the Depth or Shape of My Swimming Pool?

November 14th, 2016 by

Just move into a home with an inground pool? Decide the pool you installed needs a change? You’re not alone. Many people who have pools that were built 30+ years ago wonder if they can change the depth or the shape of their swimming pool – and they wonder how much that overhaul will cost.

For example, they don’t want it to be a diving pool anymore; they want it to be shallower. Or maybe they want to change it to a “sport bottom,” where it’s 3’ deep on the sides and tapers to 5’ in the middle. Whatever your desire for rehabbing your existing pool, there are a variety of items to address. So before you think about turning your kidney-shape into a lap pool or have any other crazy inground pool remodel ideas, here are some factors to consider.

5 Factors to Consider If You Want to Redesign Your Pool

Type of Pool

This is the biggest factor in planning and determining your budget for rehabbing your pool. Vinyl Liner Pools (Polymer and steel construction) are by far the easiest to modify. Vinyl pools are almost completely customizable and fairly easy to modify, whether that’s a cosmetic replacement of the liner or making the pool shallower by 2’. Polymer and Steel wall pools are going to have similar costs.

When tackling a fiberglass pool, modifications can become limited to add on features like a tanning ledge or a spill over spa. Many homeowners typically re-do the pool decking to update it.  Concrete, in comparison, is highly labor-intensive and requires a great deal of additional materials.


Changing your pool’s depth is a fairly simple procedure, especially with steel and polymer pools. Your biggest concern will be whether you have ample room in your backyard for machine access. If not, your builder will need to bring in a large enough labor force to dig the pool out by hand. Making a pool shallower is typically the simpler of the two. Whether you’re choosing to go shallower or deeper, if you have a vinyl pool, the bottom will then be redone with a concrete or vermiculite coating, and you’ll have your new depth. If you have a concrete pool, the same applies, it just doesn’t get covered with a liner.

One item to note: if you’re changing your pool to a diving pool, you’ll want to research diving depth standards to ensure you’re compliant with American National Standard for Residential Inground Swimming Pools (ANSI/NSPI-5 2003).


Can you make an existing pool bigger? Sure you can, but changing the size and shape of pool is a bit more difficult than changing depth. For example, let’s say you have a rectangular vinyl liner pool with a center end stair that has an overall size of 16’ x 35’6″. You want to add an automatic cover and make it a perfect rectangle. In order to accomplish this, your builder will remove some panels, add others, and maybe add a full width stair – ultimately making the pool larger, but keeping the original shape intact.

Now, let’s say you want to change that rectangular vinyl liner pool to a mountain lake shape. You won’t be reusing any existing panels, and the team will be digging and back-filling to create the new shape. At this point, it’s pretty much an entirely new pool, and you may need to budget accordingly. Some things you can do to achieve a free form feel in a tired rectangular pool would be to add some custom, free form drop in steps as a first step to customize your pool.

So before you think about making your pool smaller, you’ll always want to check with your local builder on market prices in your area. Your final modification costs to change shapes may or may not be less than the cost of an entirely new pool.

Latham Vinyl Liner Pools Rectangle (Vinyl Liner) | LEGENDS / DEEP BLUE FUSION inground pool
Vinyl Liner Pools | Rectangle (Vinyl Liner) in LEGENDS / DEEP BLUE FUSION

Return Lines and Drainage

Plumbing and drainage should also be considered in renovating your existing pool. In some cases, you won’t need an entire reworking of the plumbing system when you modify your pool. If you’re adding size to the pool, you won’t want to have “dead zones” where the water isn’t being circulated.

In general, modifications to the plumbing systems aren’t extremely labor intensive or costly. Your builder usually digs far enough into existing lines that adding return lines doesn’t require a great deal of extra work. Keep in mind this will also depend on the extent of your particular project.

When Installing an automatic pool cover, drain tiles need to be installed to get excess rain water away from the automatic pool cover housing.

Other Modifications

Changing the depth and overall “footprint” or shape of a pool are two of the most common projects. However, swimming pools can be modified or upgraded in many other ways.

Sunning ledges are quite popular today, and many owners are having them installed on existing pools. More elaborate and more user-friendly stairs are another trending modification. And people love water features, so they’re often added after the initial pool installation and a season or two of use.

How Much Does it Cost to Redo a Pool?

There are many factors that come into play when building or modifying your pool.  Time of year, soil quality, water levels in the area, size of the yard, local licensing and shipping just to name a few.  Your best bet is to write down what you would like to do to your existing pool and then work with your builder to determine the costs.  There is no obligation to move forward with the project until you are comfortable.

Meet Our Expert

Written by

Jim Eiler is a Latham Builder’s Council member and has grown up in the pool business. His dad started Aqua Pools in 1978, and they have since grown to 2 different locations in the south suburbs of Chicago, building over 100 pools per year. Jim is extremely knowledgeable in all facets of the industry and loves helping customers build their dream pools.

Join the discussion

  • Thanks for the info that the time of year will impact the cost of building a pool. It has been a dream of mine for over twenty years to have a pool in my backyard. I’ll consider these tips as I look for a pool contractor who can help me realize my dream and build a pool later this year.

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