Don't forget to read all the How To Guides, listed to the left, for information on proper assembly and finishing of your dollhouse.
When your going to put a front opening dollhouse on legs, you first have to measure the base of the dollhouse. Take these measurements to your local hardware store and have them cut a sheet of plywood to match. You do not want your plywood sheet to be thicker than 3/8"th or it will be very difficult to nail your legs to it. Stay away from MDF as well. Just make sure that you get a sturdy plywood sheet.
This sheet is basically going to be laminated to your dollhouse base to make it sturdy enough to hold your dollhouses weight once it is filled with miniatures.
I found these wooden table legs at my local hardware store. They are slightly different than the ones I used on the Gloucester Dollhouse. They are a good height though. Dining room table legs are the appropriate height for a dollhouse. You do not want to use coffee table legs because that would cause your dollhouse to sit too low. You want to be able to sit in front of your front opening dollhouse in order to view it.
These particular table legs came with screws and so they must be removed. You can use a wrench to hold the screws firmly and then screw them off. You will want to remove any staples that may be in this area using the wrench as well. If you buy a thick enough plywood sheet and have the ability to drill screw holes into it, you would be able to use the screws on the legs to screw them right into your plywood sheet but I opted to not use this method.
Once the screws and staples were off, I applied wood glue to legs and positioned them at each corner of the plywood sheet. I then used nails to attach them. I used a total of 5 nails per leg. A helping hand will be useful for this step.
Now I have four legs holding up my plywood sheet and the dollhouse base will go right on top of it. The structure is very wobbly right now but that's okay because once it's finished it will be quite sturdy.
Last time I assembled my dollhouse by working my way up from this structure. This time around, I am thinking of building the dollhouse away from it and then attaching the dollhouse, fully assembled, to it later on. Either way has it's pros and cons. You will not save yourself any difficulty no matter which way you choose so it will be interesting to see a different method.