Altering a dress to a larger size may be possible. If the garment has enough seam allowances they can be let out, adding up to two inches to its circumference. If the dress has to be sized up more than one size, restyling such as adding panels or lacings may be needed. It may not always give satisfactory aesthetic results and it may be difficult to match the fabric. The cost of restyling may be very high, because it usually requires plenty of work/time. Avoid purchasing dress which is too small.
This is also a very complicated, time consuming and costly alteration. It involves taking apart almost every seam and reconstructing the entire dress. For some designs this may not be possible. Restyling by changing the garment’s original design may be required on order to attain a more pleasing result. I would advise to consult the store alterationist before or not buying a dress two or more sizes larger.
Your bridal shop’s sales person takes your measurements in order to determine your size by a manufacturer’s chart. He or she orders your dress according to the largest measurement. They know that it will always be easier to take the seams in, then let them out. So your dress might fit at one part of your body and be too loose at another. Second reason: your dress gets cut in a factory on a very large table in stacks of dozens of fabric layers at one time with a laser knife, This way the layers may slightly vary in sizes, therefore the dresses constructed out of those pieces of fabric may have a slightly differ in measurements. And also: one seamstress will stitch for seams to be 3/8″ wide and another seamstress will stitch another dress for the seams to be 1/2″ wide. And if we have 6 seams in the bodice, that gives us 3/4″ difference in the circumference.
Your seamstress will do everything in her power to achieve that kind of result, but… It very much depends on the construction of your dress as well as your figure. It’s difficult to access the seams of an already made dress. If it’s design is complex, with lace overlay, beads, appliques, some of the seams may even not be accessible or it may be to risky to do so. Usually the side seams are the most accessible, but sometimes in order to make your gown fit changing other seams may be involved. Women have several types of bodies. Your body proportions also take a great part in determining the alterations. They may be distant from standard body measurements which your manufactured dress was designed for. For example, if you have a very large chest comparing to your waist and hips, your alterations may get more difficult. If you have a very small chest and wider hips it will be the similar challenge. Similarly with a full waist, very small waist etc… Perfect fit may not be guaranteed is such cases.
First of all it might be unnecessary to panic. Your problem can most likely be solved. Don’t allow the stress to take over. Try to be calm and communicate with your seamstress in trying to find a solution. If she doesn’t have the skills to fix the error, find a dressmaker who has the skills to make dresses from scratch. She should be able to fix any issue. Your dress is made out of several layers and parts. A part of your dress may be replaced, reconstructed or the entire dress may even be reproduced by her. She may be able to match the fabric or a bridal shop may be able to order the designer fabric for you, the same which was used to make your dress (lace or appliques). It will be a difficult task for her and sometimes some restyling may be needed. She may be able to fix your dress just in a few weeks or even days depending on how busy she is at the time.
Alterations seem to be expensive to many of you comparing to what you are paying for your dresses. Most of the gowns are produced in hundreds and thousands of pieces in overseas factories. Your alterations are performed locally. The price of your alterations includes your seamstress US hourly labor, US business taxes and expenses. Some seams, laces, beads or appliques have to be applied by hand-stitching and that is very time consuming. Bridal alterations take from 8-45 hours of work including the fittings. Wedding gowns are also the most complex garments and alterations can sometimes be more difficult than even constructing a dress from scratch.
***Remember, finding the cheapest seamstress is not a best solution, you may end up having to pay another seamstress for making corrections***