Okay, let's break this down and explore some practical and code-compliant solutions for your grounding situation. It's great that you're being thorough and consulting the ARRL materials. Grounding is important for safety and radio performance.

Understanding the Goal

The primary goal is to create a low-impedance path to ground for RF signals and fault currents. This protects you from electrical shock and reduces RF interference. Bonding your equipment to a good grounding system will also help to reduce noise. You want to minimize the length and inductance of the ground conductors.

Analyzing Your Situation House Ground

At the back corner.

Radio Location

2nd floor, front of the house.

Ideal Ground Rod Placement

Below the 2nd-floor window.

Obstacle

Driveway and Garage Extension.

Moving Timeline

5 years (limits permanent solutions).

Construction

Brick/Siding.

Addressing the Key Question: Bonding Without Trenching Under the Driveway

This is the crux of the problem. Trenching under a driveway is a significant undertaking, and if you're moving soon, it's likely not a viable option. Going all the way around the house is also undesirable due to the increased length of the grounding conductor.

Here are some options to consider, in order of preference (and compliance)


Above-Ground Bonding (With Caveats and Careful Planning) The Challenge

Running a bonding conductor above ground, especially across a driveway/garage door opening, presents challenges regarding safety, aesthetics, and potential damage. NEC (National Electrical Code) doesn't explicitly prohibit it in all cases, but it strongly discourages it. It can create a tripping hazard, be easily damaged, and look unsightly.

Potential Solution (if you proceed with caution)

You could theoretically run the bonding conductor (minimum #6 AWG copper or #4 AWG aluminum per code) in rigid metal conduit above the garage doors. This would provide physical protection and a grounded path for the conductor.

Important Considerations



Height Clearance

Ensure the conduit is high enough to clear all vehicles and equipment that use the garage doors. Consult local codes for minimum clearance requirements (typically around 14-16 feet). This often isn't feasible for residential garages.

Support

The conduit must be securely supported to prevent sagging and potential failure. Use appropriate conduit clamps and supports designed for outdoor use.

Weatherproofing

Ensure all conduit fittings and connections are weatherproof.

Bonding to the Conduit

The conduit itself needs to be properly bonded to the ground rods at both ends. Use bonding bushings and grounding conductors. The conduit acts as a supplementary ground path.

Aesthetics

This will have a visual impact. Consider painting the conduit to match the house or garage doors to minimize its appearance.

Inspection

This installation might be subject to local electrical inspection, depending on your jurisdiction's rules regarding amateur radio installations. Check with your local authorities.

NEC Implications

While not explicitly illegal (depending on interpretation), this solution is strongly discouraged and needs to be implemented with utmost care to adhere to safety and code requirements. Consult with a licensed electrician familiar with grounding and bonding practices.2.

Better Solution: Multiple Ground Rods, Radio Location Consideration Install Multiple Ground Rods

Install 3-4 ground rods along the side of the house where your driveway is. Space them at least 8 feet apart. Bond them together with solid copper wire (minimum #6 AWG). This creates a more robust ground system that can potentially compensate for a slightly longer bonding run.

Move the Radio

Consider moving the radio location to a room that is closer to the existing ground rod or easier to ground. This is often the simplest and most effective solution.3.

Using an Existing Grounding Electrode (Potentially Problematic) Cold Water Pipe

If you have a metallic cold water pipe entering the house on the same side as your radio and it is properly bonded to your house's electrical ground, you could connect your radio's ground to it. However, this is generally not recommended as the primary ground. Modern plumbing often includes plastic sections, breaking the continuity of the grounding path. Furthermore, the impedance of a water pipe can be relatively high at RF frequencies.

Gas Pipe

Never use a gas pipe for grounding. This is extremely dangerous and violates electrical codes.4.

Grounding Busbar and Short Runs (Most Practical) Install a Grounding Busbar

In the room where your radio is located, install a copper grounding busbar (a simple copper strip with multiple connection points).

Connect Everything to the Busbar

Connect the radio's ground, the transceiver, the power supply, and any other equipment to this busbar.

Run a Single, Heavy-Gauge Wire to Ground

Run a single, heavy-gauge wire (minimum #6 AWG) from the busbar to the nearest practical grounding point. This might involve a longer run along an interior wall and then down the exterior wall to the new ground rod.

Important Considerations and Recommendations Licensed Electrician

For options involving electrical code compliance and safety (especially the above-ground conduit approach), strongly consult with a licensed electrician. They can assess the specific conditions at your house and provide expert advice.

ARRL Grounding and Bonding Book

Keep reading! The ARRL book is a valuable resource.

Local Codes

Always check with your local building and electrical codes. They may have specific requirements for grounding amateur radio equipment.

Safety First

Never compromise on safety. If you're unsure about any aspect of grounding, seek professional help.

Move Radio

I know this might not be what you want to hear, but seriously consider moving your radio to the basement, 1st floor, etc.

Don't Ground to Existing Receptacle

Running a ground to the nearest receptacle on the wall is absolutely not a good ground and probably creates a ground loop.

Summary

The optimal solution is to combine elements of several approaches. Install 3-4 additional ground rods along the side of the house where your driveway is. Bond them together with solid copper wire (minimum #6 AWG). Run the copper bonding conductor up the side of your house (probably best to pick a discrete location) up to the 2nd floor, and through the brick or siding into your room.* Install a Grounding Busbar and connect everything.The above ground conduit solution is probably possible, but should be a last resort because of safety and aesthetic issues.Good luck with your installation! Take your time, do your research, and prioritize safety. Flag for review