Are you feeling pinched by the current economy? If so, your plans to move to a larger home may now be on the back burner.
The good news is that you might be able to create the space you desperately need by building a room addition. It’s important to realize room additions are small houses, and in many ways they are much harder to build than a new stand-alone home. You need special skills or a seasoned remodeling contractor who has deep experience. Allow me to share a few true stories of what happens when you don’t have the right person.
When I first started in the construction business back in the mid-1970s, I got a job as a fix-it expert for a small local remodeler. Each day, I was tasked with righting all the wrongs created by unsupervised subcontractors. Most of what I did centered around disguising out-of-square and out-of-level foundations. I can’t stress enough how important it is to have strict supervision of the foundation process. It must be square and level.
Carpenters don’t tolerate these conditions and will build a square shell on top of an out-of-square foundation. When this happens, some of the wood framing will overhang part of the foundation, and you’ll discover the foundation sits proud (sticks out) of the framing on the other side of the room addition.
My job was to cut long, tapered wood shims on one side and add a cement-stucco finish on the other side of the foundation. All this was to disguise the mistake. Some homeowners never said a word, while others knew the fix was in and complained to me. I just shrugged it off and did my job, telling them to call the owner of the company.
Foundations must be square and level. It’s not hard to do. I used an optical builder’s level back when I was building my own room additions and homes. These are accurate to within 1/16 inch in 50 feet. You can now download a simple app on your phone to give you the necessary diagonal measurements to square a foundation. I used to do those using algebra, a pencil and a piece of paper.
Stop blindly trusting your contractor. Before you even sign the contract for your room addition, you should already have the diagonal squaring measurement. Some great architects automatically generate it for you on the foundation plan. Here’s an example.
Let’s say your room addition foundation projects out from your home 14 feet and the foundation is 22 feet long. That rectangle is square when the diagonal measurement from two opposite corners is 26 feet and just under 1 inch. There are plenty of tools online that generate diagonal measurements.
You can also rent a laser level if need be for a few hours. If your room addition foundation is made from concrete block, check that it’s leveled as soon as half of the block is laid. If four or five courses of block are still to be laid, it’s going to be very hard to correct an out-of-level mistake of just an inch or so.
An optical or laser level can be used to check the pour line inside concrete forms. If you don’t want to do it on your own, put it in your contract that your builder has to help you with all of this.
It’s imperative the contractor gets the height of the foundation correct. This math needs to be done by making sure the finished flooring height matches where you will walk from your current house into the room addition. Your calculations may show that the room addition foundation needs to be higher or lower than the existing foundation. Don’t guess or hope that it all will work out.
I recommend you require a detailed cost estimate for each phase of your room addition. You want to ensure enough money has been allocated for each task to complete the job. With inflation raging, you can’t afford to run out of money before the job concludes.
Years ago, I developed a spreadsheet that helps DIYers do this. It lists every major task and most of the minor things that need to be done from start to finish. It can provide you with a rough estimate of the final cost of your room addition, if you just know the actual cost of a few of the aspects of the job.
This cost estimator works for room additions just as it does for a new home. It takes into account regional cost differences, too. You can get a copy of this spreadsheet online: (bit.ly/3JuU26t).
Tim Carter has worked as a home improvement professional for more than 30 years. To submit a question or to learn more, visit AsktheBuilder.com.