14' quite difficult lar, min 16'......if folding gate better go for 17' as the motor will take about 9" each side

14 feet for main gate with swing gate. 2 feet pillar and balance 3 feet for another small gate for people going in and out without using the main gate that will look better. If you use up all the 20 feet (19 feet actually) it dont look nice. Go round and see others then you know.

Of course the bigger the easier. My house 22 feet and I have 13 1/2 feet gate, one other car park senget a bit. I think 14 1/2 will have no problem parking both cars straight with little bit of steering. If you want to go straight in then you need to open up all your 20 feet wide house as gate.

The bigger the gate the heavy it is and heavy duty auto gate needed.

For a very wide gate, recommended to go for folding gate. Less of a hassle especially if you park outside and your gate swings out.

For 14ft gate width, if your driveway has a minimum 20ft it could be a problem depending on the type of car you drive. My gate is 16ft wide and my driveway is exactly 20ft deep but it still feels a lil tight when parking side by side as there isn't much space to maneuver. The driveway width for my house is only 18ft wide.

Go for at least a 16ft gate and maintain your driveway depth at about 23-25ft and it should not be a problem.

That mean one side you need minimal 8ft clearance.  Your front have this much of clearance than ok.

Depend your gate design, material use (steel, alloy? aluminium?) All thiese attribute will give difference weight. And look at the motor spec.

I would not recommend not stress the motor above the 90% weight written in the specification.

I'm no expert but I was told that anything more than 14 feet ( 7 + 7) is not advisable for swing gate. Also depends on the gate material wrought metal / aluminum. Mine's powder coated aluminum and 13 feet wide. I use a simple and fuss free CEI motor because I dislike motors above ground installation.

Anyway depending on the length of the driveway, using narrower gate will require you to negotiate a little when you enter the gate and try to park 2 C or D segment type cars side by side. I find with a 14 feet wide swing gate, each car is able to go in and park at the designated side by side space in the garage comfortably.

If you have open space, just put few stick, and draw a big box, that way you know what is best gate size.

Too big of a gate, sometime the house look odd. Especially very fancy gate. When i did my house, i was thinking 15', but after much consideration, i made it smaller about 13.5' and parking I have to reverse few or some extra turning. It won't kill me.

You have to consider where the incoming water meter too, and also where the main pipe, if driveway too big does it block the "longkang", water pipe.

I won't be able comment for your house. Need to see the external, your house design and neighborhood. I think you need minimal 14' also depend the car size you drive.  25' depth should be good

If you have space and high power motor even 10' per side is ok. All depend how big the open area you have.

Through experience 14 feet swing gate is good enough. 14 half if you like. Any thing bigger than that dont look good for 20 feet wide house. Gate proportionality too big make your house appear to be small, not grant. Try to balance between practicality vs looks. Also if your front driveway and the outside road is not level you may have little problem positioning your cars. Arm gate will take some space vs the traditional ones which install on the ground. You can forget about folding gate. If you really want an easy parking you can opt for sliding type. You can then take the whole 20 feet opening on either side at a time. Not necessary to have a level gate, you can make it a "m".

you need to look at the road is wide enough when your big gate is swing open for you to enter the house with ease...my area a lot of people which i dont quite understand why they park outside the house when they have space in side the house. Their parking causes difficulty to drive my car into the house if I go for swing type. Therefore i opt for folding...

And with folding type when i have visitor that park in front of my gate, I can still open the gate.

16feet medium car (city, civic) can squeeze in but need to be careful. Bigger car like Camry, Accord are no way. probably need another 1 feet each side.

Just my experience.

slightly more than 90degree

sometime we save but end up dont like it or not suitable then what's the point....

I was using a swing gate before and when my gate guy show me the new ones I asked what happen to the center stopper and lock. you can ask them to add the stopper lock in the center. Your swing door will be stopped at the stopper in the center and a metal rod will drop down and lock. new model dont use this but they do add if you want. However, I finally decided to use folding coz I did my new gate wider and hence swing gate will open quite out which is inconvenient to turn into my porch and cant park in front of my house.

yup you do have an issue with folding gate...unless you dont mind the pilar not the same size at each side of the gate.

I dont put dustbin outside coz there are dogs. And in my area, the collector comes quite punctual on alternate days. So we just put out the rubbish in the morning.  My contractor before did advice to "plant" a dustbin metal stand and put the bin on top where dogs cant topple or reach the top. You may want to consider that.

OK, good suggestion, I think I will have to go for this if I want a bigger folding gate opening.

whatever it is please check with your contractor and gate guy....dont forget your letter box and also in case you want 3phase power box (if your house is not on 3 phase now)..

So what you ended installing bro?