A 100 amp service entrance is certainly better than 60 amp, which in my opinion, is too small for today's home no matter the size of the home. It makes it easier to add central air conditioner if you have enough service panel. If you have 4 circuits rated at 15 amp plus one at 20 amp, this totals to 80 amp, leaving only enough overhead to add one more circuit in the future. Your local code may require 20 amp circuits in the kitchen. If you have two kitchen circuits, this is 40 amps already. (Some of the laundry equipment may be on the kitchen circuits.) If you have a hot water heater, it is likely a 220V/240V appliance and will use a 2 pole circuit breaker.

Normally, for reliability reasons, you do not want much of anything else on a furnace circuit besides the furnace. When you consider these points, you can see that a 100 amp service entrance is skimpy if the house has an electric water heater, furnace, and electric clothes dryer. A gas clothes dryer and water heater can reduce the ampacity requirement of the entrance panel.

I'd go for the 200 amp service entrance if you can swing the cost, otherwise, you have no other choice than to go with the 100 amp box. The 60 amp entrance is inadequate.

I am puzzled as to why your city won't allow an overhead 200 amp line. Its done in many homes in my area, in fact, my house built in 1975 has such. There's little diference in stringing an overhead line for 200 amp versus 100 amp - the wires are a little larger in diameter. The only reason that I can think of is that your city has passed an architectual code to bury electric lines, but are permitting grandfathering old installations, but saying the home owner can not substantially alter the older service size. That's silly, but that may be the way it is.

All new subdivisions developed in our area during the last 20 years have underground electrical. This have proven have more resistance to storm damage and above ground accidents compared to overhead lines. Major sources of disrupted power lines are breaking trees, ice, wind, traffic accidents, and a rare too tall load. Downed power lines are public hazards. The major hazard to an underground line is cutting into it.

I wouldn't think that a buried line on your property would be expensive. However, crossing a street is expensive when done in the covnential way - opening the street. However, it may be possible to cross a street without opening it. This is done by driving a hole drill under the street and inserting a conduit. If you have more than one electrician at you location, talk with them. You may find one who can drive a conduit under the street.

You will need to upgrade beyond 100 amp when you build and addition to your house.

You may find that you also have to bury the 100 amp service lines. I don't see why you would have to bury one and not the other.

Size of service is dependent on what you have in your house. If you have all electric (dryer, water heater, stove, heat) that is a lot different then gas appliances. Do you have a pool? AC? These thing all make a difference in service requirements. You need to do a load calculation.

The existing service drop may be large enough to carry 100 amps.

Distribution wiring does not follow the NEC.

Here in Central New York, the POCO's feed both
100 and 200Amp services with #2 Aluminum triplex
for overhead services. The underground 200 amp
is installed and owned by the customer and must
be 4/0 Al, or 3/0 copper.

It is possible the drop is over 100 feet. Our POCO will not provide a 200 amp overhead if it is over 100 feet, due to the weight. I did a 200 amp service once that was @105", they would only bring in 150A. I am not sure what size the wire was, you might check with your POCO to see if the current drop will carry 150 or even 125 amps.

Don't try to talk to the desk people, ask for a field technician who works your area.

The city told me that there is now an ordinance to bury the lines 200 amps and over. Our stove, hot water heater and furnace are gas. The clothes dryer is ready to be replaced and it will be gas. We don't need air conditioning in this area. If nothing else would upgrading to 100 amps be a good improvement to make for the future for other home improvements? Would the 100 amp service also add value to the house or would it just be an expensive upgrade to go over the 60 amps? The electrician says going up to 100 amps is a necessary upgrade.

The 100A upgrade is necessary. A 200A upgrade would be beneficial.
A 100A upgrade will NOT increase the value of a home, even from 60. 200A is becoming "required" for anything larger than a small cottage. Home inspectors love point out the inadequacy of 100A services and buyers tale their word as gospel.

IMO I would not waste my money on the 100 but go for the 200. Especially considering that you are already considering future improvements.

Don't waste your money or your time by putting in 100. As was previously said, 200 is the standard anymore, with plenty of homes going larger than that. If you are going to do this job, do it right and go for the 200. It's worth the money in order to bring the home up to standard, and it will definately be needed if you plan on an addition or a modern kitchen renovation. Those renovations won't be doable without having a 200 amp service.

So since going up to only 100 amps is not as cost effective since going to 200 would take the same labor to accomplish. Are new electrical boxes in say 150 amps up to say 195 amp available? I thought that may be a good way to go if those other higher amperages are available.

"Are new electrical boxes in say 150 amps...

They are around.

An electrician told me yesterday that it would cost $15,ooo to bury the cable, (it has to go under the street). He said our 60 amp panel is subject to failure due to its age. It has "pushmatic" breakers. He said even going to 100 would be a worthwhile update and would help with a kitchen remodel and future improvements. Does this make sense?