Building a House
One of the most important thing to keep in mind when building a house is the cost of heating and cooling it, cost which depends on the location's climate, on the building materials and on the layout of the levels.
There are several main functional layouts:
Thermal insulation: A house built on the ground usually has much less insulation under the floor than on the walls and roof, which means that it's losing several times more heat through the floor than through the walls. While the ground has a temperature that's a bit higher than the air's, so the heat loss is smaller than through the air, the difference is too small to matter. Make sure to insulate the bottom as well as the roof and walls.
Shatterproof glass: If a thief has easy access to windows, use security / shatterproof glass to dramatically improve the security; this kind of glass can easily cost 50% more than normal glass (with similar heat loss properties). Security glass does break, but doesn't fall from the frame unless great effort is applied. The level of provided security usually varies with the thickness of the protective plastic layer. Cracked security glass will stay in place, insulating the inside from the outside, for a few days until it will be replaced, which is especially good in the winter. There is also the option of installing a security film on existing windows, but it's far more secure to install security glass instead.
Bulletproof glass is a more secure option, but the price is many times higher than the price of normal glass. Bulletproof glass is much heavier than normal glass, and the thermal conductivity is high (which means a higher heat loss). An active security system, like an alarm, is useless if the thief is quick enough, or if a criminal targets the people inside.
As a side note, tempered glass provides safety because it breaks in small pieces, but not security because it falls easily out of the window frame.
No curtains: For a ground floor house, it's possible to have privacy inside without sheer curtains by installing outside, somewhere in front of the windows, decorative panels / walls made of a material (like wood) which has many cutouts through which light passes. However, these will block more of the view than curtains do.
Walled land: A tall wall around the entire land is good for security and privacy. However, this limits the view from the location (which is not a problem inside cities).
To minimize heat loss and noise getting through imperfect window installation and gasket wear, almost the entire windows area should be fixed (= not opening), with a few small windows that open for ventilation (and possibly escape in case of fire).
Is a house more expensive than an apartment? For similar conditions of location, usable space and finishes, no. There is nothing which is intrinsically more expensive for a house.
A house is made expensive by the choices made by people. They want more land for the garden, more bedrooms, more bathrooms, more space for all the rooms. They choose a layout which requires more built space for the same amount of usable space, like on-suit bathrooms and walk-in closets. They want to have space for entertaining guests, and space for visitors to stay in. These choices lead to a more restrained layout which forces the entire house layout to become less efficient.
More space requires more heating and more cleaning, so the house maintenance is also more expensive in money, time and energy spent.
There is also the issue of having to deal with all the subcontractors. Some of them might try to get from you a lot more money than their services are normally worth, so you could overpay for what you want / get. They do this in the hope that you don't know the market prices.
The bottom line is that when you want to build a palace, you will have to pay for its build and maintenance.
A single, ground level house would be quieter than any other layout because it's surrounded by most obstacles (like other houses and vegetation). Also, it's easiest to (later) build walls around the yard, walls that capture most of the noise.
The house should be standalone, that is, one which is not connected to a building where other people live.
Obstacles of great density and total mass (like compact ground around the house) are the best way to dramatically reduce environmental noise. Because of this, compact ground and concrete are good (medium and high frequency) noise insulators.
However, rigid materials are good sound transmitters, so concrete is (at the same time) a good transmitter of impact noises and low frequency sounds, which you most want to avoid. So concrete is a material which both absorbs and facilitates noise transmission, depending on noise characteristics. Because of this, if you need to avoid low frequency noises from outside, exterior walls made of concrete will not help, only a room surrounded by a lot of compact ground can help.
Compared to concrete, air is a poor sound transmitter for impact noises.
Since an underground level is surrounded by a lot of compact ground, it's much quieter than an above-ground house.
The density of the walls should be as high as possible. From personal experience, a 30 cm thick wall made of hallow brick is noisier than a 15 cm thick wall made of reinforced concrete. While the mass of the two walls is similar, the density distribution is not; also, the mortar for the bricks is not as solid as the rest.
If the external walls are made of concrete, they should be at least 15 cm (6 in) thick.
The house corners should be thick, solid blocks of reinforced concrete, each poured in one piece, because sound concentrates in the corners and you need as much mass as possible there.
U-shaped houses may amplify sound inside the U, especially very low frequency sounds; this refers to sound coming from outside the house, from the direction of the top and sides of the U (not from the bottom). If you want a U-shaped house, make sure that the width of the U is much larger than its depth.
External convex walls are reducing noise better than flat walls, but flat walls are better than concave walls. "Convex" means bulging outside, toward the noise source. "Concave" means receding inside, away from the noise source.
High frequency sounds are absorbed by obstructions, while low frequency sounds wrap around them.
If possible, place bedrooms away from known noise sources, like roads, on the side of the house which is opposite to the noise source. This is a particular concern when there are windows on the side of the road, through which noise can enter easily.
Balcony ceilings reflect outside noise toward the inside of the house.
All the perforations (windows, doors, and so on) should be on a single side, facing away from the closest / noisiest road. Note that this requirement makes the layout space consuming.
To minimize noise getting through imperfect window installation and gasket wear, almost the entire windows area should be fixed (= not opening), with only a few small windows that open for ventilation (and escape in case of fire).
The exhaust of the cooking extractor fan should exit the house on the same side as the windows.
Artificial ventilation, like air conditioning, may cause a bass-like noise in the pipes. The same thing can happen with the refrigerator and water heater (pump).
Vibrating mechanical devices, like pumps, may cause a bass-like noise.
No-freeze refrigerators make small crackling noises from time to time. If you want to avoid hearing these, especially if the refrigerator is in an open space, plan to have it encased in a fit-to-size space with a (glass) door.
Small rooms, like bathrooms, amplify the outside noise more than large rooms do. Hard wall finishings, like tile, further amplify the noise.
For good (room) acoustics, sound should be either absorbed or diffused, not reflected, by areas that are as large as possible. Straight, flat walls (including ceiling and floor) reflect and even echo sound, which makes sounds unclear / distorted / muddy. Soft materials, like textile / felt, absorb and diffuse sounds. Rigid materials, like stone, reflects sounds. Acoustic drywall (instead of standard drywall) absorbs (high frequency) sounds.
Choosing a location
If you want to have quiet, the house should be away from large urban areas, from industrial areas, from busy roads, and should face away from such locations even if they are far away, because such locations may be sources of bass-like noise.
Move away from the city center, in the suburbs. The nearby area should have no business buildings, no hospitals, no schools, no parks, and no apartment buildings.
Try to find a location where people move voluntarily in order to get away from noise. A location with old houses, where people were born a long time ago, might be noisy because those people are like most people, that is, they are not seeking quiet locations on purpose.
If you want your home in a mountain area, make sure there are no nearby tracks for ATVs and dirt bikes; obviously, these could easily pop up later. Your property should be quite large so that your house could be as far as possible from such tracks.
Look for a standalone home, one which is not connected to a building where other people live.
The much smaller density of people, combined with the lack of connected walls, significantly reduces the probability of being disturbed by noise.
This section is about a fully underground level built outside the footprint of the (above-ground) house, with only the entrance (with the stair) common with the house.
Such an underground level has the following advantages over the house:
The entire shell of the underground level (walls, floor, ceiling) must be made of thick (reinforced) concrete, and must be hydro and thermo insulated on the outside.
Because such an underground level would have a very small area of rigid walls common with the house, it should not have any common rigid walls at all. In fact, it should be distanced from any house wall with something like 20 cm (8 in). This would allow it to move independently from the house, in case of an earthquake, to avoid the risks of fractures of the connected walls. This would also allow any vibrations of the house to not be passed to the underground level. The space in between should be filled with something like polystyrene.
The soil above the underground level should have a thickness of about 50...100 cm (20...40 in).
The complicated part will be to build the stair from the house to the underground level, so that it's separated either from the house or from the underground level, yet fully integrated with the house.
Since there are no windows, it must have artificial ventilation.
Noise will be transmitted through the ventilation system (which has to open outside), so you should have a way to fully close the ventilation system, underground.
We'll choose a simple example of a house that's 30 * 10 * 3 meters, with the long front wall facing the sun made only of glass / windows. The house is suspended off the ground, to simplify calculations; if the house is on the ground, the thermal loss is slightly smaller because the ground is warmer than air and it also stores the heat which comes from the house.
The house has a frame made of reinforced concrete. The top and bottom sides are made of 15 cm thick reinforced concrete. The outer walls are made of 25 cm thick hollow brick, and the thermal insulation is made of 20 cm thick basaltic fiber (installed on the outside of the walls, top and bottom sides). Concrete pylons keep the house off the ground (with one level).
The thermal conductivity of a material, lambda (W / m / K), represents the amount of heat in Wh which is transmitted through 1 m2 of material that has a thickness of 1 m, during 1 hour, when the temperature difference between the material's internal and external surfaces is 1 C. The smaller lambda is, the better is the thermal insulation that the material provides.
The thermal transmittance of a material, U-value (W / m2 / K), is the heat loss per actual material thickness. Thermal transmittance = thermal conductivity / material thickness (m).
House thermal transmittance: HTT (W/K) = (Uw * Aw) + 2 * (Uf * Af) + (Ug * Ag)
House power loss: HPL (W) = HTT * (Ti - To)
Total energy loss for a month: TELM (kWh) = HPL * 24 (hours) * 30 (days) / 1000
Total heating cost for a month: THCM (money) = TELM * HFC
Let's say that the brick is Porotherm 25 Robust which has a thermal conductivity lambda = 0.2 W/mK, and the thermal insulation is basaltic fiber Rockwool Frontrock which has a thermal conductivity lambda = 0.036 W/mK. We'll consider that the concrete has a thermal conductivity lambda = 2.3 W/mK.
Thermal conductivity for various materials: concrete 2.3, mortar 1.73, ground 1, solid brick 0.8, gypsum board 0.17, oak 0.17, hollow brick 0.14...0.25, pine 0.15, plywood 0.13, aerated concrete (AAC) 0.11, cork board 0.043, expanded polystyrene 0.039, basaltic fiber 0.036, extruded polystyrene 0.033, polyurethane foam 0.03, air 0.026, argon 0.016, krypton 0.009.
A brick wall has an effective thermal conductivity higher than the brick's value because a lot of mortar has to be used to hold the bricks together, mortar which has a very high thermal conductivity. For aerated concrete (AAC), very little mortar has to be used.
Should you use aerated concrete instead of brick? All things considered, since most of the area of the house is (insulated) concrete and glass, the differences between these materials are too small to matter, and it all comes down to how much it costs you per m2 (material and workmanship). There is no point in spending more money for one material, unless it gives you peace of mind to use that specific material., it's not important (from a heating point of view) if the walls are made with hollow brick or aerated concrete.
The difference could be made by something called thermal mass, that is, the capacity of a material to store heat (when heated), and to release it around it (when not heated anymore). As the thermal mass increases, so does the thermal comfort inside the house, especially in hot climates where it dampens extreme temperature swings (and therefore the cooling needs). Brick has a higher thermal mass than aerated concrete.
However, the large windows oriented toward the sun make this effect irrelevant since the heat from the sun quickly enters the house through the windows. Because of this, there has to be an overhang above the windows, overhang whose depth is calculated according to the location (which affects the sun's height above the horizon); this overhang is meant to block a significant part of the direct summer sun from entering through the windows, while fully allowing the winter sun to enter.
Disadvantages of aerated concrete:
Calculating heating cost
Calculate the thermal transmittance of a layered system: U = 1 / (D1 / L1 + D2 / L2).
For the insulation, we include a 10% thermal inefficiency, so we get 0.0396 W/mK.
The house uses brick or concrete, and basaltic fiber, so we have:
You can also use Ubakus to make the calculations.
For a highly insulating triple pane windows (with frame) we have Ug = 0.8 W/m2K.
For the natural gas price in the USA, we look for the residential prices here. We choose an average price of 10 dollars / thousand cubic feet, we means 10 / 28.3 = 0.35 dollars / m3, which is about 0.035 dollars / kWh (which, as it happens, is what I pay).
For the average winter temperature in the USA, we look here. We choose an average temperature of -5 Celsius (happens to be New York).
Keep in mind that this is the lowest price determined from simple calculations. The real price will be visibly higher because of installation inefficiencies and ventilation, but you can see the level of the heating cost.
Let's say that the house gets an average of 5 months of winter per year, and let's also say that the thermal insulation has to be redone every 40 years (or it will outlive you). The heating cost for this period is 145 * 5 * 40 = 29'000 dollars. To get the entire cost related to heating, add the cost for the thermal insulation (including the workmanship); the house's area that's covered by thermal insulation is 750 m2. You can then calculate the total for different thicknesses of the thermal insulation.
The heating cost is just one factor that matters. The other factor is the cost of creating the thermal insulating envelope of the house, because this is just a heating related costs that you have to pay upfront rather than monthly. This means that if you spend too much money on insulating the house, you can end up paying more on the house than you will spend on the heating fuel, for decades or even centuries.
One way to decrease the building and heating costs is by using multiple levels. Consider that the house is divided in the middle of the long side, resulting two halves that are 15 * 10 * 3 meters. Now imagine that these halves are put one over the other. At this point, the top and bottom sides of the house which are exposed to the temperature outside are halved; at the same time, the side walls which were inside the house, along the cut, are now exposed to the outside.
Since these side walls are much smaller than half of the top and bottom sides, it means that, for 2 levels, the house's area that's exposed to the outside has decreased significantly, which means a significantly lower thermal loss (which means a lower heating cost), but also significantly less construction materials for the outside (like insulation). However, the stair (1 + 1 m wide, 3 m long, 1 + 1 m landing area) will take some 20 m2 from the useful area of the house.
The smaller the house is, the smaller the cost saving is for 2 levels. This is because the gains provided by the area exposed to the outside by the top and bottom sides end up being nullified by the expenses caused by the area exposed to the outside by the side walls. On top of this, the stair eats a higher percentage from the useful space.
For a valid comparison, a double level house has to provide a layout which is just as functional as the layout of a single level house, for a similar gross internal area (= the area inside the exterior walls); the layout must account for the stair. Because the layout is critical for a cozy home and because it will vary a lot depending on preferences, a double level house could cost either less or more than a single level house.
The single level house takes twice the land footprint, compared to the double level house. However, if the single level house is raised on pylons (with one level), the space under it remains (partly) usable.
Here are some simulations calculated for a medium-sized house located in a temperate climate.
The most important values are:
Pay attention to the percentual distribution of the "House energy loss for average winter day". It makes sense to improve / increase the insulation for the area with the highest (heat loss distribution) percentage.
Since there is no prospect of having a cheap energy source in the next few decades, you can count on fuel prices to raise. Because of this, the used fuel price is higher with 50% than the current price.
The most efficient house shape is a cube because the cube has the minimum amount of (outer) area for a given volume, which means that it has the minimum area through which it loses heat.
Basaltic fiber and expanded polystyrene (EPS) can't sustain heavy weights, like poured concrete, while aerated concrete and extruded polystyrene (XPS) can. Because of this, basaltic fiber and EPS can't be used to insulate the bottom slab, while aerated concrete and XPS can. EPS may be usable as roof slab insulation (to keep the cost down), but it can't sustain anything more than the hydroinsulation; walking on such a roof must be limited.
Don't use flammable insulation, like polystyrene, on the inside of the house (like in the attic).
In locations with large temperature variations, don't use (spray) polyurethane or polyurea foam on roofs, for either thermal or hydro insulation, because it's likely to crack and allow water to sip in. This comes directly from people who have used it in a temperate climate, where there can be 50 Celsius between summer maximum and winter minimum.
How do I design the layout of my house?
First, design your home's layout, in a home design software, in 2D design only. Create your desired rooms as rectangles (or other shapes), of the desired dimensions, and then move them around until you get the layout you feel is best.
A simple drawing tool (like OpenOffice Draw) is enough for this, as long as it allows you to resize and rotate shapes / rectangles with the mouse.
Once this is done, you can move to a 3D design software like SweetHome 3D.
How do I start designing with SweetHome 3D?
See this QA.
Is concrete more polluting than brick?
You may have heard that concrete is more polluting than brick. Cement is indeed far more polluting than brick, but buildings are made with reinforced concrete, not with cement.
Concrete is made of aggregate filling (stone), cement and steel (for reinforcement). The aggregate filling is not polluting in comparison to cement and steel, and makes the largest part of the volume of the concrete. The production of steel / rebar used for reinforcing is highly polluting, but only a small amount is required (under 3%, by mass).
This means that concrete's pollution is averaged down by the aggregate filling, and, depending on the technologies used, it can have a level of pollution comparable to brick, but on average is a bit more polluting (like 20% more).
If you want to reduce pollution then reduce the size of the house, use proper insulation, heating and cooling, and look into renewable materials (like wood). Also, choose a layout which utilizes most of the built space, by reducing empty spaces like hallways, stairs and the middle of huge rooms.
How do I choose a mattress?
See this for details.