Many dealers initially install the US2-40 or US22-40 throughout a home to provide the flexibility of simply adding a new faceplate for easy snap on/off changing as the homeowner becomes more accustomed to the power of Simply Automated lighting control.
After using Simply Automated switches for a few weeks, people frequently learn they would like to control other lights from a specific location. One common place this occurs is at the kitchen sink light. If a single-rocker dimmer switch was initially installed there, it could only control the local ‘sink light circuit’ or one lighting scene. If a multi-rocker/button dimmer switch controller base was installed there with a single rocker, it could be easily changed (snap off/on a new faceplate) to control other lights (i.e., under cabinet lights, island lights, dining room lights) individually or in group scenes.
Single-rocker dimmer switch bases (US1-40) are mostly used where there will never be a need for a multi-rocker/button switch, i.e.,. bathroom fans, laundry room or closet lights, etc... Single-rocker dimmer switches include a countdown timer function which is not available in US2-40 single circuit dimmer switch controller base (the countdown timer function is included in the dual circuit, multi-rocker/button US22-40). Single-rocker dimmer switches (US1-40) are great solutions when a countdown timer function is needed. 
First, a hot and a neutral wire should be in every switch/device junction box. This is standard wiring practice for most new construction built to national and local codes. As long as the electrician is not trying to cut corners by using a single switched ‘hot-leg’ with no neutral wire in the switch junction box all will be fine.
Second, there needs to be space in the main breaker panel (and in sub-panels that will power UPB circuits) for a phase coupler. The breaker mount phase coupler uses two 1 inch breaker positions to bridge phase A and B. If space is not available in the breaker panel, a junction box adjacent to the breaker panel should be used with necessary 240 VAC and neutral connections for the wire-in phase coupler (See Phase Coupler ZPCI-W).
Third, no need to worry about three-way or four-way lighting circuits. As long as they are wired in a standard 3-way or more way configuration, a Simply Automated dimmer switch connected to one or more dedicated remote will work fine.
Fourth, it is a good idea to check the powerline with UPStart to see if there are any powerline noise issues in the neighborhood (or in the home if the project is a re-model). Whoever will be programming the switches with UPStart should come to the property and check for noise, ideally in the evening when the neighbor’s lights and the street lights are all on.
Finally, one should consider the advantages of Simply Automated multi-rocker/button dimmer switch controller base’s ability to transmit lighting scene links and how they can reduce wall-switch clutter (i.e. reduce a bank of four or more switches to half…), or fit needed control into a single junction box space.
Since Simply Automated UPB lighting can transmit scene links, visible junction box space can be significantly reduced. This is done by using either the dual-circuit US22-40, or by using the multi-rocker/button transmitter functions of the US2-40 to control other UPB load controlling switches, which are commonly mounted in a hidden location (e.g. behind a laundry room or closet door) using standard junction boxes.
If you've ever had a situation where only one switch junction box fits but there are three or more loads to be controlled you can really appreciate the power of Simply Automated.
All Simply Automated dimmers can be configured for on/off operation by disabling the dimming function with UPStart. Fans, fluorescent lights, garage doors, gates, any load within the rated power of the UPB device can be turned on and off.
Yes, the fixture dimmer module (Model: UFD) and fixture relay module (Model: UFR) can be used to control different fixtures on the same switch circuit. The way it works is by using a multi-rocker/button switch as a transmitter only (replacing the existing switch), while using the original switch’s load circuit to provide constant power to fixture modules mounted behind the fixtures (i.e., can lights, chandelier, art/spot lights, garden lights, etc…). The transmitter’s rockers/buttons can control the fixture modules individually or in scene groups.
