PlanSnapper

Square Footage FAQ

Common questions about measuring square footage, GLA rules, floor plan tools, and what counts in an appraisal.

How do I prepare my floor plan before uploading to PlanSnapper?
Remove labels, dimensions, and extra elements around the floor plan in an image editor before uploading. This helps the auto perimeter finder work perfectly.
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Is square footage measured from the exterior or interior?
Most homes are measured from the exterior walls. Condos, co-ops, and TIC units are measured from the interior. The method depends on what you legally own.
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What if I don't have any measurements?
No tape measure and no dimensions on the floor plan? Use Google Maps aerial view to measure a wall, or estimate from standard object sizes like door widths, garage doors, and kitchen appliances.
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What file formats does PlanSnapper accept?
JPG and PNG work best. PDFs need to be converted to an image first. Minimum recommended width is 800px. Higher resolution means more accurate auto-detection.
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My floor plan is blurry or low resolution. What do I do?
Low resolution causes inaccurate perimeter detection. Re-download from the source, zoom in and screenshot at higher resolution, or use the manual adjustment tool as a fallback.
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How do I set the scale in PlanSnapper?
After approving the perimeter, click both ends of a wall you know the exact length of and enter the measurement in feet. The longest straight wall gives you the most accurate result.
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How do I measure a multi-story home in PlanSnapper?
Upload each floor separately, measure each level individually, and add the results together for total GLA. Only above-grade finished levels count.
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How accurate is PlanSnapper?
A to-scale floor plan with a carefully set scale gets within 1-2% of a field measurement. Accuracy depends on floor plan quality and how precisely you set the scale.
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Why does my PlanSnapper measurement differ from the county assessor or MLS?
Assessor data is often outdated, MLS figures are frequently self-reported, and GLA definitions vary by source. PlanSnapper measures what is actually on your floor plan.
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What is the difference between GLA and total finished area?
GLA counts only above-grade finished space. Total finished area includes below-grade rooms like finished basements. The difference can be hundreds of square feet on homes with finished lower levels.
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What is the difference between heated square footage and GLA?
Heated square footage is a regional term for conditioned living space with no standard definition. GLA under ANSI Z765 requires above-grade finished area with minimum ceiling height. A heated finished basement counts as heated square footage but not as GLA.
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What is ANSI Z765 and why does it matter for appraisals?
ANSI Z765-2021 is the national standard for measuring residential square footage. Fannie Mae requires appraisers to follow it. It defines GLA, ceiling height rules, and how to handle basements and garages.
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What counts as a bedroom in an appraisal?
Appraisers look for egress (a qualifying window or door), a closet (strongly preferred), a heat source, and adequate size (typically 70-80 sq ft minimum). A room listed as a bedroom that fails these tests will be counted as a den or bonus room instead.
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What ceiling height is required for space to count as GLA?
ANSI Z765-2021 requires at least 7 feet of ceiling height over 50% of the floor area. Sloped ceiling rooms (finished attics, cape cods) must pass this test. Only the qualifying area is included in GLA.
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How do I measure a garage for an appraisal?
Garages are never included in GLA. Measure the exterior dimensions and report separately on the appraisal form. Converted garages may qualify as GLA only if they meet ANSI Z765 requirements and were legally permitted.
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How do I use CubiCasa, Matterport, or iGUIDE floor plans with PlanSnapper?
All three produce to-scale floor plans that work perfectly with PlanSnapper. Export the floor plan image from each platform, prep it to remove labels, and upload.
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How do I calculate GLA for a raised ranch or split-entry home?
Only the above-grade floor counts as GLA. The lower level of a raised ranch is typically below grade and must be reported separately as below-grade finished area, even if it is fully finished and has large windows.
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Can I use phone photos of floor plans in PlanSnapper?
Yes. PlanSnapper accepts JPG and PNG photos taken on a phone. For accurate measurements, shoot straight down or straight on with no angle, and make sure you have at least one known wall dimension to set the scale.
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How do you measure a ranch-style home for an appraisal?
Trace the exterior perimeter of the above-grade living area only. Exclude the attached garage (never GLA), covered patios, and any unheated or unfinished space. Measure a finished basement separately as below-grade finished area.
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Does a finished attic count as GLA?
A finished attic can count as GLA, but only the portion with adequate ceiling height. At least half the finished area must have 7+ foot ceilings. Areas below 5 feet are excluded entirely. The attic must also be finished, heated, and permanently accessible.
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The auto perimeter finder is not detecting my floor plan correctly. What do I do?
Common causes are extra labels outside the walls, low contrast, an angled image, or a complex floor plan shape. Most issues are fixed with a quick image cleanup.
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How many floor plans can I measure per day?
Day pass users can measure up to 5 floor plans in a 24-hour window for $9. Paid subscribers get unlimited.
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Day pass vs subscription: which should I choose?
Pick up a day pass for occasional use or to try the tool. Upgrade to a paid subscription when you regularly need more than 5 floor plans per day.
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Can I save or export my PlanSnapper measurements?
Yes. Use Save Project to store your floor plan and measurements to your account for cross-device access. You can also export a one-page PDF report or take a screenshot.
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Are basements included in square footage?
No. Basements are excluded from GLA under ANSI Z765 regardless of finish level. They are reported separately as below-grade finished area and add contributory value but never count toward GLA.
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How do appraisers measure a basement?
Appraisers measure the full basement footprint using exterior dimensions. The same method as above-grade floors. The total is reported separately from GLA, split into finished and unfinished portions. Finished basements add contributory value but are never included in GLA under ANSI Z765.
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Why does appraisal square footage differ from the MLS listing?
MLS listings pull square footage from county records, builder estimates, or prior listings. None of which are required to follow ANSI Z765. Appraisers use exterior dimensions and exclude below-grade space, low-ceiling areas, and garages. The difference is usually legitimate, not an error.
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Does an unfinished basement count as square footage?
No. An unfinished basement is excluded from GLA for two reasons: it is below grade, and it is unfinished. It is reported separately on the appraisal form as below-grade unfinished area and may still contribute some value, but it does not appear in the GLA figure.
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How do you handle open-to-below areas and two-story foyers in GLA?
Under ANSI Z765, the portion of the upper floor that is open to below must be excluded from second-floor GLA. Measure the void on the upper level and subtract it. The first-floor area beneath is counted normally.
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How do you measure an L-shaped or irregular home for appraisal?
Break the exterior into rectangles, measure each separately, and add them together. Identify the interior corner of the L, treat each wing as its own rectangle, and be careful not to double-count the overlap area.
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What is the difference between above grade and below grade square footage?
Above grade is finished living area at or above the surrounding ground level. This is what counts as GLA. Below grade is anything underground or partially underground, including finished basements and walkout lower levels.
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How do I measure a townhouse for an appraisal?
Measure each floor separately using exterior dimensions where accessible. Party (shared) walls are measured to the centerline. Carefully assess the grade line on lower levels. Many townhouse lower levels are below grade and must be excluded from GLA.
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How do I measure a duplex for an appraisal?
Duplex measurement depends on assignment type. For a whole-property 2-4 unit appraisal, report GLA per unit. For a single-unit (half-duplex) appraisal, measure only the subject unit. ANSI Z765 exterior measurement rules apply regardless. Stacked duplexes require careful assessment of the lower unit's grade line.
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How do I measure a Cape Cod or 1.5-story home for GLA?
Cape Cods and 1.5-story homes have finished upper floors under the roofline. Only areas with 7+ feet of ceiling height count as GLA under ANSI Z765. Measure each floor separately and stop tracing at the knee-wall line. Not the exterior wall.
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How do I measure a manufactured home for GLA?
Manufactured homes are measured from the exterior per ANSI Z765, but exclude the hitch and any non-livable transport extensions. Additions count as GLA only if they are above grade, finished, heated, and directly accessible. Always measure yourself; do not rely on the HUD data plate square footage.
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How do you measure a log home for appraisal?
Log homes are measured from the exterior face of the logs under ANSI Z765. The same standard as conventional homes. Thick log walls (6 to 18+ inches) create a real gap between exterior GLA and interior living space, but appraisers do not deduct wall thickness. Use comps with similar log construction to ensure accurate adjustments.
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Does a pool house count as GLA or square footage?
No. A pool house is a detached structure and does not count toward GLA under ANSI Z765. It is reported separately as an outbuilding and its value is captured through comparable sales adjustments. Even a fully finished pool house with a bathroom and kitchenette is excluded from the main dwelling's GLA.
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How do I measure an irregular or complex-shaped home for GLA?
L-shaped, T-shaped, U-shaped, and other irregular homes are measured by tracing the full exterior perimeter as a polygon, or by breaking the footprint into rectangles and summing the areas. ANSI Z765 exterior measurement rules apply. Digital tools like PlanSnapper handle any polygon shape automatically.
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How do I measure an A-frame home for GLA?
A-frame homes are measured normally at the main floor. On upper levels, only the area with at least 7 feet of ceiling height counts as GLA -- measure from the 5-foot ceiling line inward, not from the exterior wall. If the qualifying area covers less than 50% of the upper floor, the entire level is excluded.
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Does a bay window or bump-out count as square footage?
It depends on whether the bay window has a floor. A cantilevered bay window with an actual floor at living-area height counts as GLA. Trace the exterior including the projection. A decorative bay window with a built-in window seat and no extended floor area typically does not count. Bump-out additions with a foundation almost always qualify as GLA.
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Does a sunken living room count as GLA?
Yes. A sunken living room counts as GLA in virtually all cases. The interior step-down is a design feature, not a below-grade condition. GLA grade is determined by the relationship of the floor to the exterior ground, not to adjacent interior floors. On sloped lots, verify the sunken floor is still above exterior grade on all sides.
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How do knee walls affect square footage?
Knee wall areas count as GLA only up to the point where the ceiling reaches 5 feet. Not to the knee wall itself. The room must also have at least 50% of its floor area at 7 feet or higher to qualify at all. Cape Cods and story-and-a-half homes almost always require careful measurement at the ceiling slope boundary, not the exterior wall.
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What square footage should I use for homeowners insurance?
Insurance companies use finished above-grade living area. Essentially the same as appraisal GLA. To estimate rebuilding cost. Finished basements and attached garages are sometimes included at a different rate. Do not use county assessor or Zillow numbers for insurance purposes; they are frequently wrong by 5 to 15 percent.
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How do you measure curved walls and round rooms for square footage?
Appraisers approximate curves using straight-line segments. In PlanSnapper, zoom in and place multiple points along the arc. More points means a more accurate trace. A 16-point polygon approximates a circle to within about 1% of the true area, which is well within acceptable tolerance for appraisal purposes.
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How much does floor plan measurement cost?
Costs range from $9 (PlanSnapper day pass) to $300+ for professional in-person measurement. If you already have a floor plan, PlanSnapper is the lowest-cost ANSI-compliant option. If no floor plan exists, you'll need a scan service ($40–$150) or in-person appraiser first.
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How do you measure a garage conversion for square footage?
Measure a garage conversion the same as any room. From exterior walls, but only include it in GLA if it meets all ANSI Z765 criteria: finished to home standard, permanently heated, minimum ceiling height, and directly accessible from main living area. Unpermitted or partially converted garages frequently fail one or more of these tests.
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How do you measure a tiny home for an appraisal?
Tiny homes follow the same ANSI Z765 rules as any residential structure. The main floor usually constitutes all GLA. Sleeping lofts typically do not qualify because they fail the 7-foot ceiling height requirement. Tiny homes on wheels (THOWs) are personal property, not real estate, and cannot be appraised under ANSI Z765.
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How much square footage discrepancy is acceptable in an appraisal?
No single universal tolerance exists. Fannie Mae uses a practical guideline of roughly 10% before requiring explanation, but the real test is whether the discrepancy materially affects value. Appraisers must measure independently, disclose any variance from public records, and adjust comparables consistently.
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What changed in ANSI Z765-2021?
The 2021 update clarified below-grade definitions (based on finished exterior grade, not interior floors), stairwell inclusion methodology, garage conversion requirements, and finished attic ceiling height rules. The core exterior-measurement principle for GLA did not change. Fannie Mae updated its Selling Guide to reference the 2021 version specifically.
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Why does the appraisal square footage differ from the tax record?
Appraisers measure exterior dimensions following ANSI Z765, producing an accurate GLA. Tax assessors carry forward older records, use interior measurements, or rely on permit data that may never have been field-verified. The appraiser's measurement is almost always more accurate. Gaps of 5–15% are common; over 15% warrants investigation.
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Can PlanSnapper replace a field measurement?
PlanSnapper measures from floor plans, not in the field. It can replace the manual calculation step when you already have a reliable, to-scale floor plan from CubiCasa, Matterport, iGUIDE, or a prior appraisal. It cannot substitute for a field visit when no floor plan exists or when physical conditions need verification.
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How do I measure a house when I don't have a floor plan?
Check previous appraisal reports, MLS listings, permit records, and builder files first. A floor plan may already exist. If not, scan services like CubiCasa ($25-30) generate a to-scale floor plan from phone photos in a few hours. As a last resort, sketch the exterior yourself, note the wall lengths, and upload a photo of the sketch to PlanSnapper.
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How do I read the scale on a floor plan?
Scale is usually printed in the title block (e.g., 1/4" = 1') or shown as a graphical scale bar. In PlanSnapper you don't need to calculate it manually, just pick any wall whose real-world length you know, click both endpoints, enter the length, and PlanSnapper handles the rest.
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How do I get a floor plan for my house?
Check your original purchase paperwork, MLS listing history, county assessor records, or contact the original builder. For newer homes a builder floor plan may be free online. If nothing exists, CubiCasa offers a $39-$99 DIY phone-photo scan that returns a to-scale floor plan in hours. A licensed appraiser or draftsperson can also measure and draw one for $150-$400.
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What are the appraisal sketch requirements for UAD?
UAD-compliant appraisals require a floor plan sketch showing all exterior dimensions, area calculations per level, and clear GLA vs non-GLA labeling. Sketches must use ANSI Z765-2021 exterior measurement methodology. Dimensions must be internally consistent. If they do not add up to your reported GLA, expect a Collateral Underwriter flag.
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Can PlanSnapper measure commercial buildings?
Yes: PlanSnapper measures any to-scale floor plan, including small retail, office, mixed-use, and multifamily buildings. It is built around ANSI Z765 for residential GLA, but the measurement tool itself works for any building type. For BOMA-certified commercial measurements (required for leases and institutional appraisals), a certified commercial measurement professional is still needed.
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Does a carport count as GLA?
Carports do not count as GLA under ANSI Z765-2021. They are open, unenclosed structures with no finished interior space. A carport converted into a fully enclosed, heated, and finished room can qualify, but the conversion must meet all GLA requirements and ceiling height minimums.
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Does a mudroom count as square footage?
Yes. A mudroom counts as GLA if it is finished, above grade, heated, and has at least 7-foot ceiling height. Most mudrooms attached to the main living area meet all of these criteria and are included in the exterior perimeter trace. An unfinished, unheated entry vestibule or an attached mudroom on a below-grade level would be excluded.
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Does a utility room count as square footage?
A utility room counts as GLA if it is above grade, finished, and permanently heated. Even if it only contains mechanical systems. Laundry rooms, mechanical rooms, and HVAC closets that are accessible from the main living area and meet ceiling height requirements are included in GLA. A utility room in the basement or an unfinished mechanical space is excluded.
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Can real estate agents use PlanSnapper for listings?
Yes. Agents use PlanSnapper to verify square footage before listing, catch discrepancies with assessor records, and support price-per-square-foot calculations in CMAs. Upload any to-scale floor plan, trace the exterior perimeter, and get above-grade GLA in under two minutes. Matching the methodology appraisers will use at closing.
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How do you measure square footage from a PDF floor plan?
Upload the PDF to PlanSnapper. Page 1 renders automatically as an image. Trace the exterior perimeter, set one known wall length as your scale reference, and click Calculate. Works with CubiCasa, Matterport, iGUIDE, architect, and appraisal PDFs. If your floor plan is on a later page, print that page to a new single-page PDF and upload that.
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Do stairs count as square footage?
Stairs count as square footage on the floor where they originate but not on the floor above, where the stairwell creates an open void that is excluded from GLA. The net result is that a staircase contributes roughly its footprint area once. Not twice. Double-counting or zero-counting stairs is a $4,000 to $8,000 error in most markets.
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Are there square footage requirements for VA loans?
VA loans have no minimum square footage requirement. VA Minimum Property Requirements focus on habitability. Adequate space for living, sleeping, cooking, and sanitation. Not square footage numbers. VA appraisers measure GLA using the same ANSI Z765 exterior methodology as conventional appraisals.
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How does square footage affect a homeowners insurance claim?
Insurance adjusters use square footage to estimate rebuilding costs. Underreported square footage means your dwelling coverage may be too low. Leaving you short after a total loss. A floor plan with accurate dimensions speeds up the claims process and gives you documentation to dispute an adjuster's estimate that comes in low.
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How do you measure an irregular shaped room?
Divide the room into rectangles (or right triangles), measure each one, calculate the area of each, and add them together. This decomposition method works for L-shaped, T-shaped, U-shaped, and any other non-rectangular layout. In PlanSnapper, simply trace each section as a separate polygon.
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