It is the Fungi. The simplest of all plant life. Microscopic fungus spores are all around us floating on the breeze and landing all over our homes. Wherever they land, if the 4 conditions below are present, then you will have rot and that rot will continue as long as those conditions are present.

Even if you remedy the conditions, the fungus is still present and will resume growth (aka rot) when the conditions are more favorable.

These are the 4 conditions that must be present in order for wood decay/rot to occur. Remove any one of these conditions, and you stop rot in its tracks.

1.) Substrate (Wood)

2.) Oxygen

3.) Warmth

4.) Moisture

1. Project-Specific Customer Service 

This just means some people require different services than others. This may include design work, budgetary consultations, or restrictions in access to the project. Maybe the customer has allergies that need special consideration, or they live offsite but require daily communication. 

2. Project-Specific Logistics 

This category is a reminder to help in identifying things like movement of workstations, material and tool storage on-site, proximity of parking, type of and length of access to work area, how material deliveries are handled, and even parking permits. Each project has its own set of unique logistics that relate to time and money. 

3. Project Labor 

This includes all specific project hands-on work. Not only for the standard time for installation of  the skills carpentry, plumber, electrician, or say, demolition labor, but also, for things like dust control, material hauling, workstation set up and take down, movement of ladders or scaffolding, or the time factor for all the trips it will take to climb two flights of stairs to access a small bathroom remodel, for example.

4. Project Management 

This is different than business management and project labor, and the costs for this category do not come from contractor markups. Project management refers to scheduling, having meetings with the homeowner, property owner. architect or engineer, meeting with the subcontractors— managing the project. That comes from the cost of the job. 

5. Business Management 

In my business, contractor markups cover business management costs. Whether it's a multiplier, a percentage, a combination of both, or some other calculation doesn't really matter: This portion of revenue is allotted for things like advertising, accounting, insurance, vehicles, tools, licensing, phone, internet, looking at projects, paying bills, writing contracts, business communications, owner's salary—and of course, profit!  

"When bidding a project, it's not good enough to bid by the square foot, per unit, or using any other method that doesn't account for unique project logistics." - Daniel Westbrook

RE: https://solutions.dunnlumber.com/projects/remodel-estimating-how-to-create-a-competitive-bid 

Many homeowners have had their bathroom dreams dashed because of a location that's simply too far from the main drain line to work without a major concrete and plumbing overhaul. This happens most often in basements, where the would-be bathroom's drain locations are below grade, or below the level of the main drain line. With no gravitational pull to help move waste out of the home, an alternative means of transport is necessary. Fortunately, there are two possible solutions: the macerating toilet and the sewage ejector pump. 

Be it a basement-turned-bedroom or a workshop toilet outside the house, macerating units can be installed in a number of situations, provided they're located within range of the main drain. That range is dictated by the power of the pump, and varies between models - usually it's somewhere between 10-15 feet of vertical lift and 100-150 feet of horizontal run. Many units have additional inlets to hook up a sink (kitchen sinks are not recommended), shower, or tub. Macerating toilets are safe to use with septic systems.

Note: Macerating toilets are not recommended as a primary toilet. Though this may be unavoidable in some circumstances, understand that because of the various mechanical parts working together in the unit, failure can come more quickly than with a standard toilet. Using a macerating unit all day every day will significantly shorten pump life. Even if your pump does die, don't worry: replacements are available! 

Installation & Use

Installing a macerating toilet is fairly straightforward, and can usually be completed within half a day by a highly experienced DIYer. That being said, even small installation errors can lead to bigger problems down the road - something you definitely do not want to deal with (as it typically involves a slurry of raw sewage). Study the instructions thoroughly, and follow them to the letter.

Largely maintenance-free (the macerator and pump are usually permanently sealed in an oil-filled enclosure), macerating toilets shouldn't present any significant problems when installed correctly...provided they're used correctly. Recent news stories about "flushable" wipes wreaking havoc on municipal water treatment systems have brought about an increased awareness of what's safe to put down the toilet drain. The same guidelines apply to macerating units, sewage ejector systems, and every other toilet, ever: human waste and toilet paper only - and try not to go overboard on the paper!

Pro Tip: Cleaning products that foam up can trick a macerating unit into running continuously. Manufacturers offer their own specialized cleaners, or you can save money by using plain old vinegar to clean the bowl and limescale inside the unit. When a sink is connected, try to use a soap that doesn't lather too much.

Reference excerpts: https://www.plumbingsupply.com/when-and-where-to-use-a-macerating-toilet.html