Introduction: How to Convert a Closet Into a Mini Wine Cellar

I decided to build this website after becoming frustrated while searching the Internet for practical information on how to inexpensively convert a coat closet into a wine closet. It seemed like everything was either sites for companies that sell full-blown wine rooms, or blogs by people who converted their cellar / child's room into a walk-in wine museum. Given that (a) I didn't have a large budget, (b) I only had a closet to work with, and (c) I was going to build it entirely by myself, most of what's out there on the Intertubes was useless.

So, with a handful of power tools and enough knowledge to be dangerous, off I went to build my own mini wine cellar. After numerous mistakes and trips to Home Depot, here is a chronicle of what I built and how I built it.

Step 1: A Discussion About Budget and Requirements

Before I started sketching out what my wine closet was going to look like, I did some "back of the envelope" budgeting. Most entry-level wine cooling systems, such as the ChillR, start at $500 and quickly go up from there. Replacing the closet doors with properly-insulated doors would come in around $600 (more if installed). Add another $500 for everything else, and I was easily looking at $1,600. That seemed a bit much to me. After all, we're talking about a closet, not the Taj Mahal of wine here.

Capacity Requirements

So, I started over again, but this time I thought about what are my actual requirements. Without getting into too much details, I buy in bulk in order to save money. That means I typically buy approximately 15 cases of wine roughly every eight to twelve months. That batch of wine will be consumed over the next one to two years. I do have a few "special" bottles, but I keep those in a mini wine refrigerator. So, that means I'd need to have storage for nearly 200 bottles.

System Requirements

Most wine-related sites say that wine should be kept at a constant temperature of 60 degrees. However, this requirement seems to be more appropriate for long-term storage. I wondered about what destroys wine in the short-term. After talking with some vinophiles, it seems that the factors that can really hurt a bottle of wine in a short period are:

1. Constant exposure to UV light;
2. Rapid and/or extreme temperature changes; and
3. Lack of humidity.

UV Light

The UV light issue was solved by the fact that I was building inside a closet.

Temperature Changes

With respect to temperature changes, I have a few things in my favor. First, I live in Orange County, CA, where it can get quite warm in the summer, but for the most part it's fairly mild. Second, the closet is on the ground floor with all interior walls. Consequently, the temperature inside the closet is already fairly stable.

My only real concern is during the summer months where temperatures can get into the high 90's. I'm no thermodynamics engineer, but it seemed to me that if I could insulate the closet well, the inside temperature would not fluctuate as quickly or as wildly as the outside. In other words, a little temperature change would be OK, even a larger temperature change would be acceptable, so long as it took a long time to move the thermometer.

Therefore, I decided I would forgo a wine cooling system and try out passive-cooling. And, since I wasn't going to actively cool the closet, I didn't need to upgrade the doors in order to get an airtight seal. Now, my budget was much more reasonable. Plus, I figured I could always had a cooling unit and a real door later, if needed.


Anyone who's been to Southern California knows it's not a humid place. I knew I would need to humidify the air inside the closet. Thankfully, the wife had bought a room humidifier a while ago, but stopped using it because it was too noisy. I figured that would do the trick.

Other Requirements

Finally, my wife had one last requirement: don't make anything permanent. She figured if we ever sold our house, the next owner may prefer to have a coat closet, so anything I did had to be reversible.

Step 2: A Discussion About Insulation and Vapor Barriers

To borrow from Wikipedia, R-value is a measure of thermal resistance used in the building and construction industry. The bigger the number, the better the building insulation's effectiveness. Given that I was building a passive-cooling system, I needed to maximize my R-value. Also, because I was going to humidify the closet, I needed a vapor barrier to prevent moisture from escaping.

I found an effective solution to both of these issues. Reflectix manufactures a reflective insulation that not only acts as a vapor barrier, it also increases the R-value a little bit.

For the main insulation, I decided on standard fiberglass insulation. I picked up some Owens Corning kraft-faced wall insulation, which has an R-value of R-13. While there are other fiberglass insulations with a higher R-value, this one fits inside a standard wall made with 2x4s.

Kraft-faced insulation is a little more expensive, but a big plus is that it adds a vapor barrier to the cool side of the insulation, while the Reflectix serves as the vapor barrier for the warm side.

Since I couldn't tear out the existing walls (wife's requirement), my plan was to leave the existing walls in place, build new walls, floor, and ceiling using the Reflectix barrier and the Owens Corning fiberglass as insulation inside the new drywall. For the doors, my plan was to apply two layers of 2" thick reflective rigid insulation foam board to the existing doors.

So, I figured my R-values would be:

Floor = existing concrete, existing hardwood, one layer of fiberglass insulation, 3/4" plywood = R-value ~ R-20

Walls = existing wall, Reflectix barrier, one layer of fiberglass insulation, 1/2" drywall = R-value ~ R-25

Ceiling = existing ceiling, Reflectix barrier, two layers of fiberglass insulation, 1/2" drywall = R-value ~ R-38

Doors = existing door, two layers of insulation board = R-value ~ R-26

Of course, I'm writing this website after the fact. The one thing I would definitely do differently is I would have blown in insulation into the existing walls and ceiling before building my new walls. This would have easily increased my R-Value by at least another R-10. Apparently, at Lowe's, if you buy the blow-in insulation, they'll loan you the blower for free. Lesson learned.

On a side note, that Reflectix material is great. I bought a second roll and mounted it on the inside of my garage door. We haven't hit the really hot days yet, but I have noticed a significant reduction in the garage's ambient temperature. I may do up the attic with this stuff.

Step 3: A Discussion About Tools

I have the basic array of tools in my garage. Beside the usual assortment of hammers, screwdrivers, etc., I found the following tools essential:

  • 10" miter saw
  • 7" circular saw
  • Cordless drill
  • Staple gun

If you don't already have these, I highly recommend you pick them up. My advice, don't go cheap: get the miter saw with the laser sight; get the circular saw with the laser sight; get the 18V cordless drill with the lithium battery. Think of it as an investment, since you're going to use these tools for a lifetime, or at least until your neighbor borrows it.

The only tools I needed to purchase were related to installing drywall, which included:

  • Cordless power sander (uses same 18V battery as drill)
  • Retractable utility knife
  • 48" T Square
  • Taping knife and inside corner trowel for applying wallboard compound
  • Wallboard saw

Step 4: Remove Baseboards

I figured I was going to need every inch of space inside the closet. So, I decided to pull up the existing baseboards, cut out the interior trim, and remove the electrical outlet cover.

Step 5: Install Vapor Barrier

Perhaps the easiest step was installing the Reflectix barrier. Using a staple gun, I hung the sheets, making sure no area was left exposed. Afterward, I sealed all seams using silver electrical tape.

Step 6: Install Floor

I decided to install the floor next because I needed a foundation with which I could screw into. Since I couldn't mess up the existing hardwood floors, I built an elevated floor structure using 2x4s. Cross beams were set 16" apart.

Getting the already-assembled frame to fit into the closet was difficult, to say the least. I had measured the closet's dimensions before installing the vapor barrier, so with the barrier already installed, I lost a few precious centimeters. Getting the frame in required some brute force, which unfortunately also tore up the barrier a bit. I fixed it with some tape, but perhaps next time I would install the floor first, then hang the barrier.

Once I had the frame in, I cut up the fiberglass insulation and made a floor using 3/4" thick plywood. I didn't care so much about the quality of the hardwood given that I was going to stain the floor later. Creating the floor was just a matter of placing the insulation inside the frame and screwing the plywood to the frame.

Step 7: Install Ceiling

The hardest step was installing the ceiling. Everything I had read said that a well-insulated ceiling was important, so, I decided to build my ceiling frame using 2x6s. With the extra space, I would be able to fit two layers of insulation, thus doubling my R-value.

Again, because I had measured everything before installing the vapor barrier, my frame was a tad big for the space. Also, trying to rotate frame into the closet was exceedingly difficult because I was using 2x6s. My wife patiently stood by while I screamed obscenities at the world. For whatever reason, my pain was her entertainment. If I was to do it again, I would build the frame from inside the closet, rather than fabricate it and try to install whole.

To keep the ceiling frame in place while I installed the rest of the framing, I rented a portable drywall lift from Home Deport, which cost $25 for 4 hours.

Once I had the rest of the framing in place, I cut up the necessary fiberglass insulation for the ceiling and then cut my first piece of drywall, which would become the ceiling itself. I cut out sections of the drywall so it would fit snugly around the the wall framing. I don't know if that's necessary, but I decided that any material added to the ceiling would help with insulation.

Because I was using two layers of insulation, I placed the kraft paper opposite each other, so the two pieces of fiberglass touched each other without any interference.

Using the drywall hoist one more time, I lifted the drywall into place, and secured it to the frame using drywall screws.

Step 8: Frame Out Walls

This step really happens right in the middle of the prior step, since the wall studs keep the ceiling frame in place. I only mention this step as a standalone because of the technique used to secure the wall studs to the ceiling and the floor. After perusing Home Depot, I found an assortment of framing connectors. You can see from the pictures that each wall stud was secured both to the ceiling frame and the floor using L brackets. The standard spacing between studs is 16".

One big benefit I have is an electrical outlet inside the closet. However, I was concerned with the wall plate bulging out, and perhaps pressing against the wine rack. My solution was to install the wall plate behind the drywall and then use plenty of drywall compound to smooth out the edges. The pro is that the outlet is now recessed. The con is that if I ever need to service that outlet, I'd have to cut out the drywall.

Step 9: Install Insulation

Another easy step. Fiberglass insulation is 15" wide. So, with my studs 16" apart, the insulation fit perfectly. I secured it using the staple gun. The kraft paper had ripped in some areas. I fixed it up using electrical tape.

A tip on cutting insulation: first, put something you don't mind scratching down on the ground. Then, compress the insulation while cutting through it using a retractable utility knife. If you don't compress the insulation first, it will come apart like cotton candy. Again, another lesson learned after a few mistakes.

It's important to mention that when installing fiberglass, it is highly recommended you wear gloves, protective glasses, a long-sleeved shirt, pants, and a breathing respirator. There are many respirators on the market. Home Depot had one labeled for drywall installation, so I bought that one. I don't want to think about how many years I took off my life handling that fiberglass.

Step 10: Hang Drywall

There are many other sites that can give a tutorial on cutting and hanging drywall. I will say, though, that the tighter the tolerances, the easier it's going to be to finish the drywall later. In some areas, my measurements were nearly perfect, so covering the seams was easy. In other areas, I had a few large gaps and it seemed to take forever to properly fill the gaps and smooth it over.

Another lesson I learned after the fact: Drywall comes in sheets 4' wide. Therefore, make sure you have two 2x4s studs next to each other where ever there's going to be a large, floor-to-ceiling seam. I didn't do this, so only one side of the drywall was attached to a 2x4. The other side was attached 16" back, so it has some play if I push against it. If all of this wasn't going to be behind a wine rack, I'd probably go back and fix the mistake. As it is now, no one will ever see that they don't quite line up perfectly.

OK, by this point you may have noticed that some of my pictures look out of order. It's because of the sequencing in which I built the walls. I first built the inside front and the back walls completely (i.e., frame, insulation, and drywall). Then I went back and built the side walls (again, frame, insulation, and drywall). I had to do it this way so the ends of each drywall butted up against a 2x4. Think of it like building an "L" using two rectangles. You can't cut at a 45 degree angle, so one edge is going to overlap the other.

Step 11: Finish Drywall / Stain Floor

With a large bucket of drywall compound and various compound trowels, I sealed up the gaps on the inside corners.Even though everything is going to be sanded later, it's important to try to get as smooth as possible. Somehow, sanding rough spots didn't quite get it professional looking. After I had spackled everything once, I left it dry for a couple of days. I had some cracking, probably due to settling, so I had to re-apply compound on the inside edges.

To cover the seams, I used standard drywall tape. Don't forget to buy the spray on glue.

Given that this isn't a high traffic area, I bought some minimal drywall edging to cover the outside corners.

Home Depot recommended very fine 220 grit sandpaper to sand the drywall compound. Using a power sander made it like butter. After sanding down the drywall compound, I decided to add texture to the walls. This is not a necessary step, as 90% of the walls are hidden. However, I wanted to learn how to apply texture, so I figure this was a good opportunity. Each can of texture doesn't provide a whole lot of coverage, as I went through about three cans of the stuff to get a texture consistent with the rest of the house.

One bonus regarding texture: it hides drywall seams well. Once I had everything painted, most of my mistakes were well hidden.

After covering, sanding, and texturing everything, I thoroughly wiped down the walls before painting. Given that this will be a high humidity area, I used latex paint; the same stuff you'd use in kitchens or bathrooms. Of course, don't forget to prime first.

After letting the walls dry for a day, I stained the floor using an interior oil-based stain. Home Depot had one in a color call "Cabernet". It really stood out, which is what I wanted as I didn't want it to seem like I was trying to color match with my hardwood floors. One word of caution: it takes a bit more to stain something such a dark color. Double however much you think you're going to need.

I left everything dry for several days, which wasn't a problem as I only had time to work on this during the weekends. I also had "Cabernet" wood stain on my hands and arms for several days, so don't forget to invest in some latex gloves.

Step 12: Install Trim

This step was purely for aesthetics and practice. I bought some innocuous white trim from Home Depot, plus a nice corner edge for where the new floor meets the drywall edge. Using the miter saw, the cut the necessary 45 degree angles and trimmed everything up.

Step 13: Insulate Door

Insulating the existing closet doors was a bit of an engineering gamble. The only material I found that would work is rigid foam thermal insulation board bonded to reinforced aluminum foil facers on each side. OK, so I copied that last line from the manufacturer's website, but you get the point. I purchased two boards of 2" thick Thermasheath 3 from Home Deport for about $50 per board. It's expensive, but it's also very light, is a built in vapor barrier, and has a high R-value. I figured two layers per door would give me enough insulation.

I knew that my closet door is hollow, so I figured I had about 1/2" gap to fit some sort of anchor inside the door. My basic idea was to drill four holes through the inside panel of each door. Then, slide a bolt through the insulation boards and affix them to the door with a spring-loaded anchor. I believe these are called "shelf track" wall anchors. The picture below should give you an idea of what I used.

I say this was a gamble because if it didn't work out, I'd have four fairly large holes on the inside of each door.

Two layers of insulation board are approximately 4" thick. Add in a little bit for the door itself and I needed a screw that's greater than 4" but less than 4 1/2". Unfortunately, the longest screw with an expanding anchor that Home Depot sells is only 4" long. My workaround was to push the bolt head approximately half way through the first insulation board. This gave me enough room to "pop" in each anchor. Then I just had to carefully screw tight each bolt until the panels sat firmly against each door. It's a little ghetto, but $100 sure does beat $600+.

One thing to note: I did not cut the insulation boards the exact same size as the closet doors. You can see I left a 1/2" overlap on one door. I did this to remove the air gap between the closet doors when they're closed. I didn't know if this would work at the time, but now it seems to be the right thing to do. After adding some weather stripping, it appears to be nearly airtight. The downside is that I must open the right door first.

Of course, gap tolerances for closet doors are all over the place. I found the best way to close the gaps is to use rope caulk. This stuff is a lot like silly putty. I kept adding it to the door frame until the closet door would leave an impression when closed. Also, by standing inside the closet with the doors closed, I could see where light was coming in. This stuff isn't pretty, but it got the job done. Now, the doors are virtually airtight, even a little difficult to close because the the whole air pressure thing. I don't know if it can be painted. I might try painting a test batch to see what happens.

The insulation boards settled slightly after installation, so now they drag on the ground a bit when opening or closing the door. However, it isn't harming the hard wood floors, and I suspect it helps with closing the air gap on the bottom, so I'm not too worried about this.

Step 14: Build / Install Wine Rack

I suppose this is where everyone goes their own way. I mean, my storage needs are likely to be very different from yours, so what I build may not make sense for you. I will say, though, that I found a very inexpensive wine rack system at Ikea. They have a storage system called "Gorm", which has these nice bottle racks for $8 a piece. As you can see by the picture, they come unstained, so I stained them with the same "Cabernet" stain I used on the floor.

My basic design was to use two-thirds of the space for single bottle storage and the remaining one-third for case storage. I created a main rack with Gorm bottle racks in every tier with the exception of one open tier at the bottom for champagne or magnum-size bottles. For case storage, I cut down several Gorm bottle racks and only installed them on every other tier. I had to add little vertical support beams on the sides, so the bottles don't slip out the sides when stacked. It wasn't a big deal as I had plenty of scrap 2x4 material.

You'll notice I left a slightly larger section open at the top of the case shelving. This is in case I decide to hang wine glasses later.

How much can it hold? Let's see:

  • Each individual bottle rack holds 8 bottles x 11 shelves = 88 bottles
  • Extra space at bottom of main rack = 16 bottles
  • Each case shelf holds 15 bottles x 5 shelves = 75 bottles
  • Extra space at top of case shelf = 30 bottles

That's a grand total of 209 bottles! Plus I have some extra storage on top of the rack, so I could easily get up to 220 bottles.

Step 15: Install Humidifier

There's no real instructions on how to install a humidifier. However, I think having a humidifier on 24/7 is an overkill, so I bought one of those electric outlet timers, which allows me to set the humidifier to go on for 15 minutes every few hours or so. I'm still playing around with the optimal timing. Maybe more in the summer and less in the winter.

Step 16: Postscript


After numerous trips to Home Depot, I estimate this whole project cost me right around $500:

  • $50 - Fiberglass insulation with kraft paper
  • $50 - Reflectix insulation barrier
  • $100 - Two reflective foam insulation boards
  • $100 - Wood, drywall, screws, mounting brackets, etc.
  • $75 - Paint, stain, texture, drywall compound, etc.
  • $100 - Cordless sander, other miscellaneous tools
  • $25 - Drywall hoist rental

Maybe it's an overkill for a passively-cooled system, but I wanted to set it up so I could easily upgrade to an actively-cooled system with the purchase of a cooling unit and a properly-insulated door. Who knows, I may go there once the wife forgets how much this project cost.

I put a thermometer in the closet to track average temperature, plus variance. After a week with outside temperatures in the high 90's, the closet only varied between 70 and 73 degrees. I can live with that.