How to Build a Room Addition: Advice on Working With Contractors

Building Looking at Room Addition Under Construction
Building Looking at Room Addition Under Construction. Steve Cole / Getty Images

A room addition just might be the solution to your space problems.  Less than a full-blown addition, more than refurbishing existing space, room additions suit the needs of many homeowners, both in terms of space and costs.

Seasoned contractor Larry Mock, owner of Portland Oregon's Cascade Custom Remodel & Construction, offers advice on building a room addition.  Mock has four decades of experience in the construction industry.

1.  Even Contractors Want You To Get 2 or 3 Other Bids

Though it seems preposterous, most contractors do not want you to hire them for this crazy enterprise if you are not 100% certain.  If you jump on the first contractor that comes your way, you may get cold feet later on.  Contractors do not want to be the first one that you choose; instead, they want to be the chosen result after all of your careful research.

Mock says:

I suggest interviewing 3 to 6 contractors, and then checking the last 10 projects the contractor has completed. One should also check with their state contractor's board for any complaints there. Angie's List and LinkedIn also offer ways to check on contractors.

2.  Too Many Bids Can Be Too Much

Soliciting over 5 or 6 bids wastes time--your time and the contractors'. Mock advises:

Bidding is a time consuming and costly process. Please don't waste contractors' time by having 6, 7 to 8 contractors bid on the same job. On a simple bathroom, I personally invest 4 to 6 hours, the other subs, another 8 to 12 hours... At $50 per hour, which is low by any standards for what we do, that represents $600 to $900 in time. I personally will not bid against more than two others and many times will not bid at all. 

3.  Good Bids Will Be Closely Clustered

If you have chosen the contractors well, most of the bids will fairly close within the same range:

The point I am making here is that in my 40 years of remodeling, contractors who have the same passion and determination as we have, are generally very close to our price. 

4.  Be Careful of Those Really Low Bids

When you get that too-low bid, this may be an indication of a problem.  It may not necessarily indicate a scam operation.  It may just mean that the contractor doesn't fully understand what you want and is bidding based on a scaled-down idea of your vision.  Mock recommends:

The last thing a home owner wants is the lowest price or a contractor who goes out to bid to get the lowest price in each category. This is a recipe for disaster.

5.  Remove Emotions From the Process

Contractors are in the business of construction and remodeling, not nursemaid, psychologist, and therapist.  He says that:

Remodeling is more about emotion than anything else. Yes, we have to maintain high quality, predictable and reasonable schedules and finally, a fair price. Many folks choose a contractor based on their first impressions or the lowest bid, which you and I both know this approach can create a plethora of problems.

6.  Exhaust All Other Options First

Room additions are not your first option; they are your last option.

Due to the price and complexity of building a room addition, you should exhaust every possible solution to your space and living issues—before undertaking this project.

  • Throw:  There is a structure that is about 12 feet long and 8 feet wide that is far cheaper than any room addition you can build.  This structure is called a rolloff container, or Dumpster.  Fill that with unneeded household detritus before even considering a room addition.
  • Rearrange, Organize:  Closet organization systems work wonders for cluttered bedrooms.

7.  You Must Be Able To Work With the Contractor

With a room additiongetting the contractor right is essential.

Your relationship with this contractor hinges on how well your personalities mesh.  But do not expect to become great pals during this project; this is primarily a business relationship.

The main issue is the contractor's reputation and how the owners feels about him/her. After all, that contractor is going to become a family member for the better part of 4 to 16 weeks depending on the scope of work. So having a contractor with a great rep and that they feel good about can lead to a successful project for all concerned.

8.  Sunrooms Are Not an Acceptable Substitute

No doubt about it:  sunrooms are attractive. They cost less than full-scale room additions, and they give you just as much square footage.

But sun rooms are just that: sun rooms. Most do not have plumbing, showers, bathtubs, toilets, and other essential services.  Most significantly, they are usually not conditioned (heating and cooling).  

Build a sunroom if you want a conservatory-type feel, but not because you think they will substitute for a real addition. 

9.  If Resale Value is Your Thing, Consult a Realtor or Appraiser

Are you putting on the room addition purely for your own benefit? Or do you care about resale value when it comes time to sell?

Even though you cannot do things just for the benefit of some nameless, faceless potential buyer sometime in the distant future, you do need to give some thought to resale value. Not all room additions give back adequate resale value.

The Realtor who sold the home to you will be more than happy to tell you how this added square footage (and the type of square footage you’re thinking of) will benefit you in the long run.

10.  Realize That You Are Building a Mini-House

A room addition involves all of the same things that you find in new home construction: foundation, footers, framing, zoning, permitting, HVAC, flooring, plumbing, electrical, new windows, etc. The list goes on and on.

Even if you are building a great room or living room (i.e., a room addition without services such as plumbing), you still have other services that you cannot avoid (electrical, heating, cooling, and more).

11.  Learn to Think in Terms of Square Footage Cost

Room addition building is complex. The only way to make sure you are comparing contractor estimates on a level playing field is to compare on a dollar-per-square-foot basis. But you’ll want to make sure that all contractors are bidding on the same thing, or your square footage cost comparisons will be all wrong.