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Modifications & Customization of House Plans

house plans design modificationsThe House Designers has been around since 2001, but some of our contributing architects and designers have been in the business for decades longer than that. Hundreds of thousands of homes have been built from plans on our site, and a significant percentage were custom homes built from our stock plan designs.

One thing is certain about the vast number of homes we sell: almost everyone makes changes to their stock plans. Customizing the design to suit your needs can address issues with your lot, ensure the home meets the special requirements of your locality, or just make sure your personal preferences are met. Here are some of the ways that you might make modifications to your purchase to make the home your own.

Mirror prints

It's no problem to build your home as a mirror image of its plan, so it better fits your lot or places the garage in a more desirable position. Mirror prints, where the plan is printed in reverse, are available from all members of The House Designers. Some provide fully reversed plans, where the lettering reads directly, but in most cases the lettering will be reversed—so you should still order basic sets of the plans that you can easily read. To see what's available, check out the plan packages available on the page for the particular plan you are interested in.

Red-lining blueprints

This is by far the most common way that changes are made, and it is also the simplest and least expensive route to choose. Although our industry uses the word "blueprints," this is a holdover from the old days. All the plans used for construction today are printed on white paper with black or blue line lettering, and notations are easily made on them. They can be made by pen, pencil, or a red line pencil, which stands out very clearly—hence the term "red-lining."

Red-lining is not suitable for major modifications, but it is good for the vast majority of changes, such as:

  • shifting interior partitions that have no effect on structural spans
  • extending a wing of a house lengthwise that has no effect on structural spans
  • material changes, specifications, fixtures, cabinet layouts, contract provisions, etc.
  • shifting, adding, or changing windows or doors
  • addition or deletion of fireplaces, garages, false dormers, raised or dropped ceilings, etc.

If your modifications involve anything other than some material or specification notes, red-lining is best done by an experienced contractor who is familiar with your local codes and would know if the changes require further input from a local professional. Because plans may not be photocopied, make sure to order enough sets—usually at least 5, though many customers choose 8 sets—so each can be noted with the proposed changes. A red-line set is acceptable for contracts, most lending institutions, and most building departments. If you are building in a very high wind zone or a flood plain where local engineering is required, red-lining might be unacceptable.


Where major changes are possible, a reproducible is suggested. All members of The House Designers provide these; again, please see the plan packages on the page for the specific plan you are considering. The reproducible allows an experienced local draftsperson to add, erase, or draw involved changes to any plan. Reproducibles are also helpful where local engineering or code modifications are required. Changes that can be made with our reproducibles include:

  • enlarging the home in any direction, even where roof pitches or rafter lengths are changed
  • adding a room, garage, or porch
  • changing the foundation type, if not available with the basic plans (most are available, so check first)
  • elevation changes including roof pitch and roofline changes
  • significant interior layout changes
  • adapting a plan to meet local codes or to provide engineering where required

Reproducibles are best modified by a local architect, designer, or engineer, but may also be modified by an experienced contractor. Authorization is provided to enable you to make prints from the reproducibles at a local copy shop. Copy shops are not permitted to reproduce house plans without such authorization.

Some member firms also offer CAD files for modifying plans. These are the electronic files that contain all the information on your blueprints. Special restrictions may apply to the use of CAD files, so check with the specific firm. Direct 800 phone numbers for each firm can be found on the Contact Us page.

Customized blueprints

You might be able to use the original architect or designer of the home you have chosen to make changes to customize the plan for you. A number of firms offer to customize their plans, but even if the designer of the plan you are interested in doesn't, do not hesitate to call us. They may have a plan in their extensive collection that already includes the changes you are considering, or we can customize the plans for you in-house.

Remember that the architects and designers in The House Designers are committed to helping you obtain your dream home and will help steer you in the right direction!

© 2019 The House Designers®, LLC. All rights reserved. All house plans and images on The House Designers® websites are protected under Federal and International Copyright Law. Reproductions of the illustrations or working drawings by any means is strictly prohibited. No part of this electronic publication may be reproduced, stored or transmitted in any form by any means without prior written permission of The House Designers®, LLC.