If you’re in the US.

Any time you have a height difference of 30″ or more you need guardrails 42″ high.

Ian Marr·June 25, 2020Architect

There are several ways to answer your question.

The whole earth? The mantle makes up the bulk of the Earth, so liquid.

From the ground up? By volume? That would be the atmosphere mostly, so gas.

From the ground up? By mass? Either liquid (the oceans) or solid (solid matter) depending on how you define things.

David Smith·June 25, 2020

Ahh, not so fast. You have forgotten temperature and pressure. By the time you get down to the Nickel-Iron core, we are dealing with a gas which is under hypercritical pressure The so called solid core is this same hypercritical gas so compressed that it behaves as if it were solid. The temperature is so high that chemical bonds are completely unstable, so technically it is a PLASMA. It is an interesting property of plasmas, that their electical resistance is close to zero. Very nearly superconductive. Have you noticed that when a household filament lamp bulb fails, it often takes out the house fuse. The electric arc created as the filament fails has a much lower resistance than the intact filament. It is this very high conductivity of the Nickel Iron core which is responsible for the Earth’s magnetic field, and the fact that the inner core behaves as if it were solid, which maintains the system of differential flow which sets up the self exciting electric generator, possibly driven by the Moon, which is responsible for the Earth’s magnetic field.

You’re missing some information in your question.

In order to answer this question you need to have decided the number of treads and risers. At 117″ you can have risers at about 8″, but this is steep for most people (15 risers). Most residences are around 7″ (17 risers) to 6″ (20 risers).

You have one less tread than risers. We aren’t going to count the nosing (the part that sticks out past the riser). Again 10″ can work, but most people don’t like them. 11″ to 12″ for treads work well in most homes.

So, take your riser count. Minus one. Multiplied by your tread size.

You’ll get somewhere between 140″ (very steep) to 228″ (easy to walk up).

Also, be aware that there are a number of different ways to size stairs, and that this is just one that easier to explain and understand.

In my field, we would probably just call that a beam. We might give an additional descriptor like flush, drop, or similar.

No.

The cheapest method would be to adjust the temperature of your house the least amount possible.

Other than keeping your house at an extremely different temperature from its current one, constant temperatures require constant cycling of the system. Unfortunately, this is exactly what most thermostats are designed to do because they are easier to make and easier for people to operate.

A number of persons have covered this subject, but maybe I can address it a bit differently.

Pierre L’Enfant did the masterplan of Washington DC back right before 1800. This was to be the great city of the west with every detail mapped out including all future buildings and monuments. At this point, a ten story building was gargantuan and considered unappealing to most. As such, they weren’t really apart of the plan.

A hundred years later elevators are commonplace in large buildings and allowances were made for taller buildings, provided they stayed within defined proportion (hence the 130′ limit).

Washington DC was designed as an eternal city. It’s just that 200 years later we can see that there are a number of things they didn’t see coming. Like tall buildings with elevators. Otherwise, Washington DC is exactly what L’Enfant imagined: a city as a monument.

That would be the U-value or heat transfer coefficient. It is measured in watts per sqft*Kelvin.

The easiest way to find this is to look up the R-value or insulation value of a specific material per inch thickness. From there you find the inverse, which is the U-value.

You can find R-value lists all over the internet.

Principally Douglas Fir (also Larch which is frequently marked as Douglas Fir).

Less common, but still used:

• Hemlock
• Common Fir
• Southern Pine
• Spruce

Also, most stair lumber is rated #1 at a minimum.

Both can be good but it will come down to the following:

• Environmental conditions
• Specific loading
• Relief joints – the biggest single issue if all others are equal

The height or type of building isn’t what decides pile foundations, or rather they are secondary reasons (the weight of the building). The quality of the soil on which it is placed is the primary reason.

If the weight of the building exceeds the bearing capacity, has a geologic hazard, or provides an unsuitable layer with an acceptable shortly below piles are one of the solutions.

Keep in mind that if your engineer(s) are doing piles it isn’t because they want to use them (they require quite a bit more work for them).