More than 17 million new homes and apartments are being built in the United States each year, more than half of which are low-rise buildings designed for one or two families. Very popular apartment low-rise buildings from 2 to 5 floors.
Almost all cities or territorial entities have their own rules and laws for construction (Construction COD). In many cities, the maximum height of buildings, the width of roads, sidewalks, the capacity of built-in garages, the ratio of the area of the building spot to the total area of the site, the distance between buildings, the amount of electricity consumed, the distance from the house to the public roadway, etc. are legally fixed. Many cities severely limit and rationalize the maximum size of the area of houses, used building materials (especially for the construction of external structures), prohibit the installation of fences, outdoor lighting, use water supply for watering lawns. In recent years, tougher requirements for thermal insulation of buildings. In this case, the most important controller of construction is the representative of the creditor bank.
Most cities have long-term master plans for development and clear zoning for low-rise and high-rise buildings, industrial and recreational areas, waste management, trade, public parking areas, etc. This planning is based on long-term economic development forecasts and financing opportunities. All plans are provided not only financially, but also technologically. Many cities for the development of urban plans attract foreign architectural planning companies or companies from other cities and states.Wood in American construction
The main structural material for low-rise construction is coniferous wood (the transverse size of the boards used is 50×100 or 50×150 mm). The use of simple structures was the result of the practice of building the first settlers and many years of competition among manufacturers. At the same time, they meet the requirements of the modern market. As a building material, wood showed its superiority above all by its durability. In the US, a huge number of wooden buildings are more than 100 years old.
Wooden structures are convenient and easy to use, allowing for the realization of a variety of architectural ideas. In addition, it offers a huge number of ready-made house projects for almost every taste. The cost of such a project does not exceed $ 1000. A developed trading system, free competition, open information, a good legal basis and ease of obtaining loans make the construction of houses of any type accessible to the majority of the country’s inhabitants .
The predominant type of housing in the United States are single-family one- and two-story houses, which are built, as a rule, in the suburban area of large cities, in medium and small cities, in rural areas. About 65% of the population lives in homes of this type, including 40% in the suburbs, 28 in the cities and 32% in the countryside.
Modules and blocks,
mainly from wooden structures, are widely used . Earlier in the construction of frame houses used chipboard (DSP), characterized by low mechanical characteristics. Structures made of oriented strand board (OSB) replaced the chipboard.
Many houses are partially or fully assembled in the factory for several days. The total duration of the entire cycle for the construction of the house (from the moment of taking the order to its delivery to the customer) is no more than 8 months. Considering that a large number of houses are manufactured at the factory and delivered to the site with ready infrastructure, the actual period of their construction directly at the site should not exceed several days.
Multi-apartment 2-3-storey residential buildings are built in the United States from the same materials as single-family ones. They are intended for middle-income families who cannot buy their own home.
For low-income families in need of social assistance, multi-storey houses are being built, as a rule, of frame type from solid concrete. At the same time, construction is on average 60–65% paid for by the state through subsidies . Despite the fact that 10% of apartments are empty – not rented out or not sold, millions of single-family and hundreds of thousands of multi-family rental houses are built and sold annually in the United States. And about 70.5% of residential buildings are bought on installments for a period of 20 to 50 years.
High-rise buildings of 10–16 floors are being built for low-income people in the United States. On the basis of such houses, autonomous residential areas are being built, consisting of 5–10 houses of different heights. The first floors are designed for built-in grocery and industrial stores, utilities, schools, sports facilities, garages. Apartments in such houses have from three or more rooms. The cost of an apartment in a similar house is about 20 thousand dollars, which is quite affordable for families with low incomes. However, this type of housing in the United States is not widely spread. Moreover, there are cases of its mass dismantling.
As noted above, the basis of housing in the United States are wooden structures. The panels are manufactured at the factory – on compact and inexpensive equipment. The cost of production lines ranges from 150 to 350 thousand dollars depending on the technical features and configuration. With this technology, almost any building materials available in the local market are used in the internal and external decoration of houses and their engineering support. A high insulating properties of the wall structures gives a structural modular panel. For frame technology, strict adherence to and deep understanding of its essence are decisive factors in terms of the quality of the finished house.
How well the house is reliably assembled, dried and protected from moisture in the process of preparation and its construction – depends on its service life and also the consumption of energy resources during operation.
With accurate implementation of design solutions for wall installation, a saving of heat in comparison with a brick house is achieved by 2–2.5 times, an increase in the internal area by reducing the wall thickness and, consequently, saving the budget during operation.
Residential arrays do not require the installation of expensive heating networks, because Autonomous technical systems using electricity, gas and other fuels are used. This allows you to completely eliminate heat loss during its transportation. Sewerage and water supply systems can also be autonomous. Demands on the quality of the housing stock are increasing. Among the criteria for the quality of housing assessment, along with the convenience of the internal layout of apartments, the saturation of equipment, reliable heat and sound insulation are becoming increasingly important.
In the American program “Affordable Housing” for the poor it is stipulated that the construction of the city does not have a negative impact on the ecology of the city. Therefore, the projects provide for the demonstration of indicators of energy intensity, environmental friendliness, information about the materials used, methods of their delivery, destruction of construction waste, take into account the order of operation of the building, its maintenance and liquidation after the expiration of the service life.
Houses under construction fully comply with the most stringent standards, are beautiful and diverse in terms of architecture, environmentally friendly, and most importantly – the cheapest of all possible options for American construction in mass production.Cement in American construction
Cement production in the United States is the third country in the world after China and India. After the reduction of construction production as a result of the 2008 crisis, cement production in the United States in 2010 amounted to 62.8 million tons. Part of domestic demand is provided by imports, which also decreased from 32.2 million tons in 2006 to 6.3 million in 2010. Cement trade in the United States is seasonal: its maximum consumption is from May to October. At the same time, the achieved average capacity utilization rate in the United States in 2011 was high and amounted to 82.0%. But even with such an indicator of capacity utilization, the country’s cement production was not able to meet the demand for cement in the domestic market. In America, the bulk of the cement industry is concentrated in one particular region. This affects the cost of transporting cement, which in most cases exceeds its selling price. 96% of produced cement is transported to the consumer by cement trucks.
The United States for many years topped the list of countries importing cement. Presumably, the country is guided in this case by the need to save its own energy resources. Thanks to this, for many decades in the States, energy-saving wooden house-building has dominated.
During the crisis period, cement imports into the country declined and amounted to 11.5 million tons in 2011. This situation forced the United States to raise the issue of improving the efficiency of cement production and commissioning additional production capacity. By 2012, more than 25 million tons of new fully automated energy-saving cement capacities, worth more than $ 6 billion, were to be commissioned in the United States. Currently eleven cement plants are under construction. The implementation of this project will cost $ 1.8 billion. Particular attention was paid to reducing the cost of cement and its energy intensity. In the process of modernization, the number of wet-type furnaces decreased by 80%.
Over the past 20 years, the automation of production and the closure of small furnaces have reduced employment in the US cement industry by 23%. Despite the fact that the construction of housing was carried out mainly in a wooden frame design, the country’s demand for cement grew. This is due to the fact that not only a part of low-rise housing is erected in the monolith, but also high-rise buildings for various purposes, industrial and social and cultural facilities, dams, energy complexes, television towers, roads, overpasses, etc. .Construction technology
Now in the United States for one average salary a resident can buy 2 m2 of living space (see table), we are talking about poor customers. This indicator is the highest among the countries listed. But in order to achieve it, we need:
- ?? organization of high-performance production;
- • prepared construction sites (with water, sewage, electricity, if provided by the project, then natural gas);
- ?? car drives;
- ?? availability of project documentation for the construction of material and energy efficient houses with the developed technology of its production and construction (factory production of the house from different materials, 70% in wooden and frame-wooden design).
Note. Here it is appropriate to say about the possibility of solving the main issue of housing construction in the USA – its financing. There was a lot of information about the “functioning of the US economy in debt.” The United States is now the world leader in debt growth . He currently stands at $ 14.3 trillion. In the financial capital of the United States, New York, in its main square, Times Square, there are original watches – they show the national debt of America. The money for the payment of US debts is mainly taken from the issuance of its securities or actually borrowed from its own population and foreign investors. In practice, the case is organized in such a way that the US economy is provided at the expense of the rest of the world. To cut the budget deficit the United States can not, because only at the expense of budget spending is the country’s economy alive. The US lives for many years at the expense of debt, they used to live like this, practically without returning them. Already 74 times the congress raised the debt ceiling, but he is not talking about paying it off.
The ratio of the cost of 1 m2 of living space and the average wage
Price 1 m2
Number of m2 for 1 salary
USA, New York
Great Britain, London
The economies of most countries are tied to the US economy, so many of them will fly into the projected financial blockage (and there are more such forecasts). Essentially, a part of such money is the source of this result in the number of square meters of living space that an average American can buy.
In the 1930s, a powerful institutional framework was created in the United States for active state housing policy. The task of increasing the number of homeowners has become an important element of national policy. Even before World War II, US President Roosevelt, by organizing state support for housing loans, turned the country into a so-called “one-story America.” The landlord has become one of the main objects of state care and support of its economic policy. In addition to subsidies and incentives for credit institutions, new technologies have played a role in the development of “one-story America”, which makes it possible to speed up and cheapen construction. After the Second World War, the production of standard wooden houses in the state of New York was put on stream. Suburban settlements of cottages and townhouses began to be built everywhere.
US authorities intentionally stimulated Americans to move to the suburbs. Thus, the newlyweds and young families with children were provided with government assistance for buying houses outside the city, the American authorities directly stimulated the growth of suburban housing for the poor population. The necessary transport infrastructure was established. The enacted National Law provided for the construction of high-speed concrete highways of strategic importance. The active construction of roads combined with low gasoline prices favored massive suburban construction. Many enterprises also moved to the suburbs, followed by shopping and entertainment centers. Only in 1996, 2.7 million people moved from the city to the suburbs, while in the opposite direction only 800 thousand people moved.
The turnover of the “industrial housing industry” in the USA in 2000 amounted to almost $ 19 billion, of which about $ 7.5 billion (about 40%) is the turnover of the cottage market. Taking into account the fact that modular technologies are also used in the construction of shops, public buildings, offices in industrial enterprises, the mobile homes sector accounted for about $ 3 billion a year, the remaining $ 4.5 billion was panelized homes, non-mobile cottage modules and the same log homes .
One of the users of LiveJournal published on YouTube (YouTube) a detailed report on the construction of frame wooden houses in the southern United States, in Houston, which will be the subject of further detailed consideration. We are talking here about building a dedicated area with low-income families. The district includes:
- ?? irrigation system;
- ?? sewage;
- ??treatment plant;
- ?? roads;
- ?? infrastructure for recreation.
The whole area, in turn, is divided into districts, approximately 90–150 houses. Infrastructure is created separately for several districts. The population of the built-up area will use the system of shops, banks, hospitals, educational institutions, sports grounds and other public institutions that were built in advance, taking into account the plan for building the area and increasing the number of residents.
Practically in a clean field all communications are laid: gas pipes, water supply, electric cables, telephone. All communications are connected to substations and technical hubs. In this work, the trencher and pipelayer on the basis of the tractor are actively used (see photo).
Then built roads and sewage. Near all sewage drains are stacked red sandbags, their goal is to trap dirt during rains and prevent clogging of sewers. Plastic sewage pipes, pipe diameter starts from 60 cm, increases with the length of sewage. Sewer grids are usually absent, instead of them there are open water intakes, inside of which there is a sewer shaft about 2×2 m. All pipes, if possible, are not under the road, but next to it, repairs are carried out from the mines. All road signs are installed. There is no road marking in the sleeping areas, there is a speed limit of 20 km / h. Signs of speed limits are also absent, the speed is written in the rules of the road. The height of the curb is 15 cm.
It is very interesting to travel in such areas with all the signs placed, but the complete absence of houses. Pay attention to the ribbon of grass, laid along the curb, it prevents the washing of dirt from the lawn into the street during the rain.
After all communications are laid, the irrigation system is prepared. She is paid special attention here, since Houston is prone to tropical storms and hurricanes. Usually the depth of artificial reservoirs is about 10–12 m. All reservoirs have a system of locks and channels for diverting water. The shores of an artificial reservoir are concreted at the level of the pool to protect and prevent erosion. So that the water does not wash away the concrete, a part of the land near the concrete strip is reinforced with clay and rubble. Next is the preparation of sites for homes.
At the same time build 20-30 houses. They are mainly built nearby, it facilitates the cleaning of construction debris and does not bother those residents who have already settled and live in previously built houses. Exceptions are homes that were purchased in advance at some specific sites. To lay the foundation slab, one meter deep soil is taken out and covered with a layer of gravel, sand and clay, all of which is compacted. This foundation solution is used only in Texas because of very clayey soil.
In the north of the United States for the most part applied strip foundation. In the same period communications are supplied to the house (gas, cold water, sewage, electric cable, etc.).
Formwork for the foundation is assembled, after which the earthen base is covered with dense plastic, fittings with a diameter of 10 to 16 mm are installed. It is laid every 3-4 m crosswise with the exception of certain places (for example, a garage, an entrance to a house, a cut of the foundation), here it is laid according to the design of the house. All foundations are solid, monolithic, the slab thickness is about 25–30 cm. Before the concrete mixture is poured with the concrete pump, the reinforcement is pulled out and anchored to the formwork. To fasten the walls of the house to the foundation, dural anchors (anchors) are installed in the concrete body. To prevent the formation of cracks in the concrete, the foundation is made of water. The usual average size of the base plate is 20×15 m.
The marking of the walls is applied on the surface of the set concrete, and the assembly of the wooden frame of the house begins. Wooden structures are fastened with nails and metal anchors. Also used screws, bolt fasteners, mainly on the critical “nodes”. The wooden bar is practically not used. All the supporting structures of the house are assembled from the board. Outside, the frame of the house is sheathed with a DSP or OSB plate 2 cm thick. Glass wool is inserted into the frame apertures from the inside, after which the wall is sewn up with a gypsum board.
It is noted that the sound insulation in the house is very good, despite the seeming fragility of the walls. The cries of “zombies” from the nursery are not audible at all in the hall, just as children do not interfere with a working TV in the bedroom. All wood materials for the construction of houses are pre-treated with compounds to protect against insects and moisture. At the same time, chemical impregnation is not harmful to humans. Fire protection of wooden structures is carried out.Internal engineering communications
Next, the house is lined with bricks; in addition to bricks, natural stone is used. Between the wall and the clutch there is a 5-6 cm gap for air circulation. After the device frame house and exterior cladding finished, inside begin to conduct communication. Plastic pipes with a diameter of 6 cm are used for sewage. Communications are laid inside the walls: electrical wiring (yellow wire), television (black), white – the Internet.
For water, plastic pipes with a diameter of 13 mm are used, which withstand a pressure of 0.7 MPa and a temperature of 95 ° C. In the attic is installed ventilation system of soft fiberglass pipes for heating and cooling the house. From above, it has a shell of non-combustible fiberglass, under which glass wool is hidden, inside which there is a soft aluminum tube. Today, such ventilation pipes are used wherever the air flow rate does not exceed 30 m / s. With a higher air circulation rate, a rigid ventilation system is installed.
Equipped with a bathroom and toilet, fireplace is installed. In homes, all the fireplaces are usually gas, they are much easier to install, because They do not require masonry and problems with valves. In some homes, real fireplaces are built by order of the buyer.
Install a jacuzzi, shower, shpatlyuyut drywall. Inside the house, painting and tile laying begins, sockets, switches and other trifles are installed. Then everything that can be scratched or damaged in the process of work is protected. The laid tile is covered with thick thick paper, all the windows are still in films, the bathrooms are covered with special covers.
In parallel, the laying of flexible ruberoid tile on the roof. Attention is drawn to the use of a conveyor belt mounted on a car chassis for the supply of roofing material.
In different areas, all the roofs are made in the same color using the same material (tile, roofing felt, etc.). It is not profitable for companies to build poorly, the declared warranty period for a house is from 15 to 50 years (for various elements), so after each operation the engineers check the quality of the work done, otherwise the company will have to repair everything at its own expense. Inserted windows. The windows used in construction are “southern” and can only be used in Texas, Louisiana, Florida, southern California, Arizona and New Mexico. The windows have a value of U equal to 2, the heating coefficient is 0.23, and the light transmission is 0.43. The outer part of the house is sheathed with additional noise insulation and insulation polystyrene panels with an R value of 3, the thickness of these panels is 13 mm. Top panels will be sewn with a layer of thick plastic and roofing material.
The roads are monitored, they are constantly cleaned and washed. The shield shows the plan of the district, which was previously mentioned, it is from them that the built-up areas consist. For several of these districts build pools, playgrounds and other infrastructure.Evaluation of American technologies for the construction of frame wooden houses by residents of Belarus
Judging by the comments made by Belarusians on “YouTube”, they are familiar with the American practice of housing construction, someone may have worked for a certain number of years in the construction of houses in the United States. Some categorically oppose such construction and literally say that:
– the houses are very bad;
– burn quickly;
– by car, if you enter, then Khan’s house will be;
– a worm can eat a tree (you will have to buy a woodpecker instead of a cat);
– Americans built it is very bad;
– surveillance cameras everywhere (you can’t do anything bad, as they can put it on YouTube);
– too much empty space (you need to earn a lot, or you will feel lonely in such a house);
– we all know that there is nothing better than PANEL HOUSES (booths, chicken coops, boxes);
– ordinary frame-shield houses, nothing special and supernova;
– Karkasnik – the cheapest kind of home, this is its only advantage. All the rest are solid flaws. Did you live in a skeleton ball? I lived and no longer want;
– now the people are building only villas – doing the right thing, because the villa will easily stand for 2-3 generations, and not this one-time hut;
– they do not withstand Belarusian frosts, we have minus 15 and we have to burn a fireplace at home all night or the boiler is fully operational. So “fufel” these houses are almost the same in value, you will win a couple thousand. In a fire, a match will burn out;
– I would not buy such a house! All the walls are fake, but cheap. In short, photoshop – and nothing worthwhile! Reinforced concrete is worse, but not by much. Deal is rubbish!
– it is asked, why in Europe to build a skeleton of incomprehensible material (RSD), if it is possible to build it from bricks or gas silicate blocks;
– Houses from the “cardboard” – frank shit, and in our edges it also comes out more expensive than from the blocks, which in themselves store heat well, are cheap and very easy to build. And quite different in strength. The simple fact is that, thanks to the Belarusian mentality, built houses come with 300% wrap;
– I lived in such a house, quite a good house for $ 130,000. And what does RB offer us ?? Concrete crap with retarded courtyards or a solid cottage in Ratomka for $ 350,000, which 80% of the population of Belarus never save;
– well, well, “wooden house”, lined with stone or brick … Very good, not bad! Hurricane blown away? Yes, our gas silicate houses will not be stronger than these …
Other participants have their own opinions:
– The average incomes of the residents of the United States and the people of Belarus are different, it is not even disputed, but they (the Americans) are building cheap and relatively affordable housing. The time from the start of construction to the settlement is 3 months maximum (!!!), and we “beat down stone fortresses” with all our strength. Where is the logic?!
– but we have all the millionaires, we also have a brick and reinforced concrete blocks (panels). It turns out that we live richer, because such houses are available to us. Where to us Finns or Canadians;
– The cost of such houses is very interesting. Without taking into account the price of a plot, $ 150,000, and a plot of thousands more
for 100-150 American dollars will pull?
– Americans consider such houses to be good housing for people with average incomes. For relatively little money you get housing, and quickly. And for example, a good “brick” in Colorado is worth the money;
– All options have the right to life. One says this, having studied the experience of Canada, Sweden and Norway, where 50 percent or more percent of housing is built up with such houses;
– Of course, the construction of houses for us is flimsy! But the main thing that is striking here is the process of construction itself! All neat and quality. Did you notice? That first build a concrete road and communications. It is evident that everything is thought out!
– people are able to do! Because they are friends with the head and they know: they did poorly for the customer’s money, you will do well for yours! Plus you will kill your reputation, you will also pay compensation!
– in general, here we see an indicative construction process! All neat and high quality!
– and we, that private owners, that gosUKSy, all the construction process is organized equally bad!
Note. It is impossible to agree with this, a lot of Belarusian construction projects are organized at a good level. As for the laying of external communications and roads, there are probably cases when they are built some time after the completion of the construction of the house, which is unacceptable. But in the area of Kamennaya Gorka, these works were carried out before the installation of houses.
– infrastructure preparation is, of course, five plus. Why do we have everywhere no one deals with this issue? Would take “developers” plot, cut, laid all the future of the house and sell “fifty dollars.” Will take, how to drink to give.
Statements about the organization of production
The whole area intended for building is divided into districts, approximately 90–150 houses. 500 dollars per 1 m2 is a lot for us. It means that 50–80 million in one district, houses will normally pay off, if everything is done on the basis of factory constructions and in-line (carpet) way, and due to this it is necessary to catch up with the West in construction performance. But in our country such construction obviously will not work at least for reasons of price. For $ 500 per square, there are 90–150 customers for this construction, not to mention large volumes.
Participants in the discussion on this subject say:
– you need to learn yourself and, most importantly, give the opportunity to learn young professionals (they will lead large-scale construction projects tomorrow) – educate modern construction organizers. What is wrong with the proper performance of work, the economic feasibility of the technologies used and the calculated energy-saving materials and structures of them? Take the best, more economical technology possible !!!! By the way, change the TV screen saver in laptops, parade exhibited on the tables of meetings in high instances;
– technologies and materials can be used any, progress is not worth it, but new principles, techniques taking into account the requirements of saving material and energy resources and labor costs in construction, a modern qualified designer and manager will always benefit from it. We have the same building technology for many years;
– here you need to understand: we see typical US housing, so it should be compared with typical housing in Belarus – with panels. Believe my experience: sockets lose 100%;
– such houses in the USA are built for businessmen and for stars. Brick and stone houses are built only as houses for tens of millions of dollars. At least half the cost in this case is the labor of the bricklayer and the materials;
– the framework is not sheathed with OSB, but with OSB plates, and this is not plywood at all, but a fire, moisture-resistant particle board;
– there is no ban on OSB (in response to criticism of OSB). Have you ever been to Poland, Lithuania, Germany? In these countries OSB is the most popular building material, take a ride, look, a lot of houses are built from them. In Germany, a little less, in Scandinavia, almost all new houses are carcasses, in which OSB and variations from its plates are used. And the big authorities should know that without this material there will be no new technologies in the construction of low-rise buildings, and productivity in construction will not increase.
There were opinions and technical order:
– yes, the foundation needs to be calculated. Bored piles will do, bearing in mind that a wooden frame, which is much lighter than a traditional block or brick house, will rest on it;
– and here is the question, but where can we buy land with communications, excellent road and other infrastructure?
– unfortunately, the fact that, from the position of progress, we don’t think anything in advance is a fact. Therefore, the construction is stretched over the years with the creation of unbearable conditions for all others.
As you can see, the opinions are very different. The main thing is that the solution of organizational and technological issues is carried out in a complex (and not all of the applied factors are presented here), ensures high labor productivity and quality of housing construction in the USA. Attention is paid to the flow of construction of American houses, it is emphasized that it gives a high speed of building houses and provides high indices of natural output for various types of construction and installation works.
A significant contribution to the acceleration of construction makes the device permanent concrete roads prior to construction. Moreover, the communication pipes are placed next to the road (it is possible to break it down in case of increasing communications), a device along the border of a ribbon from grass that prevents erosion of the lawn. Continuous monitoring of the condition, maintenance along with cleaning provide the roads in working condition.
Use in the construction of the frame and cladding of the facades of houses with boards, OSB plates instead of energy-intensive cement and bricks. The use of drywall eliminates plastering. It can be seen that the continuity of the flow cannot be organized without the use of weekly daily planning and corresponding daily monitoring of its implementation. The quality of construction operations is ensured by the highly qualified performers and verification by the engineer after each performed work.