How to measure a window for replacement in Fort Myers - and why the standard rules don’t apply here
To measure a window for replacement, you measure the width and height of the existing window opening in three places each - top/middle/bottom for width, left/center/right for height - and use the smallest measurement. But if you live in a concrete block home in Fort Myers, that standard advice can cost you thousands. The three-point rule was built for wood-frame houses with a consistent rough opening. Walk into a 1965 block home off McGregor Boulevard and that same approach will get you a window that doesn’t fit and a lead time you can’t recover. Call us at (844) 638-7249 if you want a professional measurement that’s tied to your upfront price - so there are zero sizing surprises after the contract is signed.
Written by Derek Hollenbeck, Owner & General Contractor, Groundwork Construction Co. of Fort Myers, serving Fort Myers since 2014.
What makes Fort Myers window measurement different
Most of the homes we work on in Fort Myers - especially anything built before 1980 - are concrete block construction. You’re not measuring the inside of a wood frame. You’re measuring the masonry opening: the raw gap in the block wall where the window sits. Sometimes there’s a wood buck attached to the block face. Sometimes there isn’t. And you need to know the difference before you order a single unit.
Here’s what we look for on every measurement visit in Lee County:
- Is there a wood buck? If yes, we determine whether it’s structural (tied to the block and staying) or decorative (coming out during replacement). Measuring to the buck when the buck is being removed is a classic mistake that yields a window a half-inch too small on every side.
- Block face to block face. On buck-less openings - common in mid-century Fort Myers homes - we measure the masonry opening directly and specify the window’s frame depth to match the wall thickness. A standard vinyl frame won’t always seat correctly in a 6-inch or 8-inch block wall without furring.
- Impact window frame thickness. Impact-rated units, which are required for most of Fort Myers under Florida Building Code wind-borne debris rules, have inherently thicker frame profiles than non-impact windows of the same nominal size. We’ve seen homeowners measure for a standard Andersen unit, order the impact version, and discover the frame is 3/8-inch wider - meaning the rough opening is now too tight. That’s a reorder and a four-to-six-week delay.
Our Windows & Doors in Fort Myers team handles this every day. It’s second nature to us now, but for a homeowner measuring once, the margin for error is real.
Out-of-square openings: a pre-1980 Fort Myers reality
Concrete block homes built before 1980 in Fort Myers - and there are thousands of them, from Dean Park to Pine Manor - rarely have perfectly square window openings. Decades of settling in our sandy, high-water-table soil plus original construction tolerances that were looser than today’s code mean an opening can be out of square by a quarter-inch or more. That doesn’t sound like much. It’s everything when you’re installing a rigid-frame Hurricane Impact Window rated for 160+ mph winds.
When we measure an opening in an older block home, we don’t just take three width and three height measurements. We also check diagonal corner-to-corner measurements to identify the degree of out-of-square before a window is ever ordered. If a replacement unit needs to be slightly undersized to fit a skewed opening, we spec that upfront - and the trim and flashing plan accounts for it. If you skip that step, the window arrives, the corners bind, and the installation turns into a masonry modification job that wasn’t in the budget.
Derek Hollenbeck has been looking at these openings since he was a kid growing up in the Iona area, and later running crews across Lee County. He’ll tell you: the tape measure doesn’t lie, but it also doesn’t tell the whole story unless you know what else to check.
The cost of a wrong measurement in a permitted Lee County project
Here’s a scenario we’ve seen play out more than once since Hurricane Ian. A homeowner pulls a building permit for a window replacement, measures themselves, orders six impact windows, and the first unit out of the box doesn’t fit - a risk that proper Hurricane Shutters & Protection planning can help avoid. The permit clock is already running. Lee County’s permitting pipeline has processed tens of thousands of post-Ian permits, and while things are moving, a reorder means the job stalls. The homeowner is paying carrying costs or living with a hole in their wall while a replacement unit is manufactured - and that’s weeks, not days.
A typical Fort Myers Windows & Doors replacement project runs between $4,500 and $15,000, and a single mis-measured impact window reorder can add $400 to $800 in change-order costs plus the time delay. We eliminate that risk by tying our measurement to the upfront price. Our technician measures every opening, documents the type (masonry, buck, or frame-in-frame), notes any out-of-square conditions, and that spec becomes part of your contract. If something doesn’t fit because we measured wrong, it’s on us - not on you. That’s covered under our 730-Day Done Right Promise: if it’s not done right, we make it right.
How Groundwork’s measurement process actually works
When you call us for window replacement, measurement isn’t a separate fee or a “we’ll figure it out later” step. It’s built into the project from day one. Here’s what happens:
- A background-checked, uniformed technician arrives at your Fort Myers home - always on time, always with a marked Groundwork vehicle.
- Every opening gets measured with a laser distance measure and a traditional steel tape for backup. Laser gives us accuracy to 1/16-inch. The steel tape confirms it.
- We check all four diagonal dimensions on older block openings and photograph any out-of-square conditions. Those photos go into your project file.
- If we’re installing impact windows - which we nearly always are in Fort Myers, given the Wind-Borne Debris Region requirements - we spec the frame thickness at measurement, not at order. That means the Andersen, Pella, or ViewLux unit we quote is the exact unit getting installed, down to the frame profile.
- The measurement data feeds directly into your upfront price quote. No bait-and-switch. No “we discovered the opening is a weird size” change order three days into the job.
We’ve been doing this for over a decade across Fort Myers, and after Ian, we saw a wave of out-of-state crews who took deposits and disappeared. We’re the opposite. We answer the phone live, 24/7. We show up. We measure once, order once, install once.
FAQs
Window replacement in Fort Myers typically runs between $4,500 and $15,000, depending on the number of windows, whether you choose impact-rated units (required in most of the city), and the frame material - see our guide to Hurricane Windows Cost in Fort Myers, FL for detailed pricing factors. A single impact window replacement often falls in the $800 to $2,500 range per unit installed. Call (844) 638-7249 for a free, no-hassle estimate tied to your actual measurements.
You can, but we recommend against it. Concrete block openings in Fort Myers homes built before 1980 are frequently out of square, and impact windows have thicker frames that change the tolerance stack. A measurement that’s off by even 1/4-inch can delay your project by weeks. If you’ve already measured and want a second opinion, we’ll send a technician out at no charge to confirm everything before you order.
The unit arrives, doesn’t fit, and you’re looking at a reorder that typically takes four to six weeks - plus additional shipping and potentially a change order fee from your installer. If the project is permitted through Lee County, the permit clock is ticking the whole time. We prevent this entirely by taking professional measurements before anything gets ordered, and our upfront pricing locks in the cost based on those measurements.
Yes, for almost every home in Fort Myers. The city sits in a Wind-Borne Debris Region under the Florida Building Code, requiring windows to meet impact-resistance standards (typically Large Missile Impact rated). Impact windows have thicker frames than standard units, which directly affects your measurements. If you measure for a standard window and later upgrade to impact, the opening may no longer be sized correctly.
Get it measured right the first time
If you’d rather have a professional handle the measurements - and tie them to an upfront price that won’t change - call Groundwork Construction Co. of Fort Myers at (844) 638-7249. We offer free estimates, 0% financing for 18 months, and $1,000 off projects over $10,000. A live person answers, day or night. We don’t just break ground - we build something worth standing on.
Written by Derek Hollenbeck, Owner & General Contractor, Groundwork Construction Co. of Fort Myers at Groundwork Construction Co. of Fort Myers, serving Fort Myers, FL.