Hot bonus room above garage

[kelled77]

Well- we recieved quotes for the attic fan, and had an insulation contractor come. We actually have all the proper insulation according to him. He did say while he was in the attic, that he noticed there was ice on one of the feeding freon lines. So, our heating and cooling company added freon and it is so much cooler. Our heating and air contractor comes out twice a year for maintenance. They were here in April and the numbers were ok according the them. We must have a leak- just not sure if it is a big one or small one. I am glad we didn't spend $1000 on an attic fan, and glad to know we have proper insulation. Who knows what this freon leak is going to bring about- but thank you for all your advice. I really, really appreciate it.

[shootingarrow]

Should I Build A Bonus Room Above My Garage?

Sounds simple enough doesn't it? Deceptively simple, I reply. Building a bonus room over a 3 car garage is easy. Doing it correctly is another thing!

We've all heard that it's cheap SF, in fact it's almost free! Well, it's less expensive than kitchen SF but certainly not free. There is also the cheap bowling alley method and the more sophisticated, expensive method. Frankly, it depends upon the intended use of the space. Bedroom, office, play room, teenager hang out space or home theater are examples of what the space can be used for.

What makes that building space so challenging?

1. There is attic space on 3 sides and a garage on the other.

2. Providing enough daylight.

3. The space is long and narrow.

4. Attic ventilation is more difficult to achieve.

5. HVAC design.

6. Strange design ideas.

7. Egress

Let's take each issue, one at a time.

1. Summer attic temperatures in Central Florida can exceed 150 degrees F. Unlike most parts of a home, bonus rooms have attic space on three sides. Additionally, due to truss configuration they are difficult to insulate with fiberglass batts. Sure you can strap a 10" batt of fiberglass (R-30) insulation on the attic space side walls but it doesn't seal very well. Special care must be taken when insulating. Though I'm not normally a fan of spray foam insulation, should-i-install-spray-foam-insulation-in-my-attic-or-fiberglass- a bonus space over a garage is ideal for spray foam. Foam provides a high R value in a small space and normally you only have 4" in which to insulate. The thickness of the vertical truss 2x4 web. The floor of the garage bonus, normally a has plenty of space to insulate with an R- 30 fiberglass batt but care must be taken to place insulation up against the bottom of the sub floor and not suspended below the floor sheathing leaving an unconditioned air space between the batt and the sub floor.

2. Sure it's easy to position a single or double window at the far end of the room but that makes the room feel like a bowling alley. Other lighting options must be explored. The dreaded skylight that always leaks (I don't care what the manufacturer says),



dormer windows or some other light providing design. Doing it right is obviously more expensive. The very last thing you want to do is install double french doors with an exterior balcony at the end of a bonus space. That's a guaranteed leaker! Ok, I know, the Plan Designers do it all the time because it looks so cute and you see it on homes all over Central Florida. Don't believe me, use the "knock on the door test"! Go to 5 homes that are older than 5 years, knock on their front door and ask if they are having any issue with leaks on the cute Romeo and Juliet detail. Find out for yourself.





Notice- the lack of overhang protection and the in-swing double French doors. I'll bet money this leaks like a sieve!

This is a great example of a plan designer drawing a detail that's not in the Owners best interests. It's not an installation issue, it's just a bad design idea. No Builder can do anything that will stop this combination of issues from leaking. I've even watched a door knob leak on a detail like this in a driving rain!

3. The typical 3 car garage dimensions are 32' wide x 22' deep. When building a bonus room, the goal is to get maximum useable SF. Certainly not a ceiling height of 2' but something reasonable. I've stretched to a 4' height at the extremes because you don't normally stand right up against the side wall but it's pushing it if you are 6' tall. The trick here is the interface between Architect, Homeowner, Builder and the truss manufacturer. There is a point of diminishing returns where the cost of engineering a longer truss or closing the spacing between trusses exceeds the benefit. This is where hiring the right building team comes in.

4. Attic ventilation is of particular concern with a bonus space above a garage. Most attic spaces are ventilated by air flowing into perimeter soffits, rising along the attic side of roof sheathing then exiting vents positioned toward the peak of the roof. Anything that blocks that air flow is a problem. An over heated attic space can cause a lot of issues from cooling of the interior bonus space to moisture removal. As soon as a Builder expects a tradesman to see an issue that is beyond his normal thinking, there is a problem. Expecting a painter to think "waterproofing", a framer to think "attic air flow" or a roofer to think "attic Ventilation" there is going to be a problem. THE BUILDER IS THE ONLY TEAM MEMBER THAT SEE THE ENTIRE PICTURE. That's why hiring the right Builder that has years of experience is so vital. He knows from years of problem solving what to look out for. He knows because it bit him in the butt before!

5. The best way to air condition bonus space is with it's own designated unit! It's difficult enough to condition living area that has attic space on 3 sides and a hot garage on the other, without tacking the bonus space air conditioning ducts onto a system that is already cooling another part of the house. If you don't want to have a hot bonus space, better make sure it has it's own HVAC unit. This is an area where the Builder has to bring the HVAC contractor into the the design early to avoid issues down the road. It's too late once the house is designed and the framing is complete. At that point, all the HVAC contractor can do is make the best of a bad set of options.

6. Strange design ideas is another area of concern. I've seen dormer windows that are 2' wide drawn on plans by Architects. Why is that an issue you ask? A narrow dormer translates into a long unusable light-shaft in a bonus space. Depending upon the pitch of the roof, a poorly designed dormer can be a huge waste of space and an eyesore. Imagine a 3' wide space 10' long! I'm not talking about just one of these, picture 2-6 of these baby's! Now you get the picture! Big time ugly! A dormer can be designed in such a way to make it wider so it can be a space with a desk or other useable area not some ugly unusable light shaft. As you can see, a well designed bonus room is not just some after thought that is slapped on a home design at the last minute. It takes a team of dedicated members lead by an experienced Builder to do this correctly.

7. Egress- a really important issue to think about now instead of when you have a fire. Lets say, you designate the space over the garage a “Play Room” on the building plans and end up using it as a sleeping space for guests or worse, one of your children. I’m guessing this happens all the time. So what’s the big deal? The building codes are way different for a sleeping space than for other uses and making the area a sleeping space is more difficult to design. When a living space is designated as a bedroom there has to be a smoke detector in the bedroom and one between the bedroom and the kitchen. Additionally, at least one window has to be large enough for a person to climb out of in case of fire. That’s just not going to be possible with a 2’ wide dormer window. All issues that require careful planning now before the Builder just slaps some “almost free” bonus space above your garage.

Have an awesome day-

Mike

[amberamour]

We have the bonus over the garage too. Ours is subject to western exposure, in the South. For the first couple of years it was the hottest room in the house in summer and coldest in winter. Ceiling fans did not increase our comfort significantly but mostly blew around warm air.

We have more than adequate insulation. Extra was put into the attic right before we moved in 4 years ago.

During an a/c service call we talked about the problem achieving a good comfort level in the bonus. The technician suggested we close off the a/c return in there, which is a small one and was not doing anything (too far away from the unit and not drawing enough to be effective). I'm sure people do have separate a/c systems for their bonuses but we don't and did not want to add one.

The other change suggested was to modify all the vents in each room so they were not diverted anymore, including the bonus. This was done by using a needle nose pliers.

These two changes solved our issues of comfort in the bonus room and whole house. And the electric bill went down a little too.

A third smaller change but still important was to use the proper a/c filter with about 20 pleats that don't affect our air flow like the ones with say 55 or more pleats. I had been using the cheap fiberglass ones not because we didn't want to spend more but because the hepa type, heavily pleated ones seemed to block the overall air flow severely.

Since doing those things our bonus room is now the coldest room in the house in summer and warmest in winter. No extreme is good or perfect but we're very satisfied.

You might want to schedule an appointment with a good a/c technician and see if you may improve your comfort by improving how your existing system and how you are using it can be changed.

Best of luck and enjoy the frog! We love using ours now!