There is a lot to think about when it comes to making renovations on your home, which is why it can be hard to avoid making costly mistakes. Your renovations are likely already making a significant dent in your bank account, and you will want to avoid any unnecessary spending that mistakes can lead to. Extensive research and advanced planning are vital to a successful renovation project, but even during the planning process there are many wrong turns you can make. Here are a few mistakes to avoid during the home renovation process:

1. Not selecting a trustworthy contractor

Selecting the right contractor may take time, but it is certainly worth it, as someone who is unqualified or lacks the right experience can ruin your project. Monica Higgins, founder of construction management firm Renovation Planners in California, told U.S. News and World Report that homeowners should not only use former customers as references but should also conduct legal, financial and criminal background checks to make absolutely sure the contractor they want is equipped to do the job. 

If your contractor does a bad job, it will negatively affect your living situation and could also affect your ability to sell your home. Any issues that are not visible to the naked eye will surely be discovered during a home inspection

Nino Cutrufello, co-founder of home builder Callahan Ward in Havertown, Pennsylvania, explained to the Philadelphia Media Network that a good contractor should provide at least a one-year warranty to allow the new work to experience every season. No matter how good the work is, it is at risk of some damage as temperature and moisture conditions change, so make sure to get the warranty in writing before the work begins. 

2. Underestimating costs 

It is almost a guarantee that your renovation will cost more than your initial estimate, so do not begin the work unless you have a contingency fund that contains an extra 5-10 percent of the renovation's estimated cost. 

In addition, there are several extra costs associated with a renovation that homeowners may not think about. Dean Bennett, owner of Dean Bennett Design and Construction in Castle Rock, Colorado told the Philadelphia Media Network that in addition to the cost of the project itself, there could be costs adding up to thousands of dollars related to sales tax, shipping, interest, permits, deliveries and more. Make sure you consider these factors when determining your budget. 

3. Failing to obtain a permit 

According to HGTV, it is imperative you research the rules in your neighborhood regarding renovations. You may be required to obtain a permit, build within certain standards or even get an inspection. If you don't get a permit before you begin the work, you are likely building illegally and may end up having to rip out your entire renovation and start from scratch. It may seem time consuming to push through all of that red tape, but it will save you tons of time and money in the long run. 

Architect Rick Goldstein, co-owner of Atlanta-based design and building company MOSAIC, told U.S News and World Report that homeowners should not listen to contractors who tell them a permit is unnecessary. Not only could the failure to get a permit result in the demolition of your project, but you could also end up paying some hefty fines.

4. Changing your mind in the middle of the renovation 

Changing your mind is okay sometimes, but it is important to understand the consequences. According to Houzz, changing your mind mid-project will always end up costing you more time and/or money. Every change results in a long process of shifting schedules, ordering new materials and more. If some part of the project has already been completed and it doesn't fit with the change, it may even have to be torn out and reinstalled. 

5. Expecting a return on things that can't be seen 

U.S. News and World Report said buyers will be willing to pay more for a home with visible upgrades, such as new appliances or countertops. Something like a new electrical system, on the other hand, may not be something a buyer is willing to pay extra for. Still, a faulty system will most likely be discovered during a home inspection and could affect the price and appeal of your home. It is important to get the "invisible" issues taken care of because while a buyer may not be willing to actively pay more for new systems, he will definitely demand to pay less for systems in poor condition.

Making renovations to your home is a big decision and should not be done lightly. Before jumping in, make sure you have done all the research and feel confident you have taken all of the necessary steps to ensure an efficient, cost-effective renovation process.