It is not difficult to build a foundation on a flat site with modern technology. However, sometimes sites for future construction are located on steep slopes. Houses located on sloping surfaces have their own advantages: they are better protected from wind and flooding, and are more profitable in price. In addition, the view from the mountain is usually impressive. But under the influence of heavy rainfall and groundwater, the soil gradually softens.
In the future, this can lead to a shift in the upper layers of the soil. To protect yourself from unpleasant consequences, you should choose and build the foundation correctly. How to do this, this article will tell.
Building a foundation for a house on a slope is a difficult process that requires a special approach and adherence to technology, because the foundation is the main component of each building. For a sloping surface, a tape, pile or stepped base is usually chosen.
First you need to calculate the angle of inclination, measured as a percentage. If the slope is near the 10 percent mark, this indicates a high slope. The steeper the slope, the more effort and materials may be needed. If the angle of inclination does not exceed eight percent, then the piedmont part can be sprinkled with soil. If the angle is more than eight percent, then you have to build ground floor.
It is worth remembering that the foundation on a plot with a slope cannot be higher than four of its width. Before construction, the site must be divided into squares and anti-landslide measures should be taken on each of them.
The strip foundation is one of the most popular designs today. However, experts advise building this type of foundation only on slopes with a minimum slope. It is also worth considering the various contraindications of surveyors.
The strip foundation is a closed contour of reinforced concrete beams and is laid both under the external and under the internal walls, if necessary. This type ideal for structures with heavy floors, and also if the plans include the creation of a basement. There are two types of strip base: monolithic and prefabricated.
The pile foundation is a solid structure of piles that are dug into the ground and united from above with supports. Many experts agree that the pile foundation is the best for the construction of load-bearing structures on slopes. This is an effective and practical option for arranging a foundation at any depth.
The installation process is simple, although it requires special equipment. In addition, this type is cost-effective compared to other options. Piles can be made of wood, reinforced concrete or metal. Heaving soils (clay, loam, sandy loam) have special requirements. Here the pile foundation is also appropriate.
Tape
pile
The columnar view is also suitable for building a foundation on a slope. It provides for the erection of pillars in all corners. However, some nuances must be taken into account when erecting it: each pillar must be secured by a supporting wall, which enhances the stability of the base. The columnar version is economical and reliable, does not require additional waterproofing. But it is applicable only for wooden or frame houses.
The stepped foundation has a cascading arrangement in the form of ledges. It is suitable for steep hillsides where leveling cannot be done for any reason. The general slope of this option is fully consistent with the natural slope of the site. The laying of a stepped foundation looks like a classic concrete strip, built from steps of different heights.
A slab foundation with a height difference on a site with a slope is the best solution for building houses and cottages made of brick, aerated concrete and other materials. This version of the base provides reliable support for low-rise buildings and is particularly durable.
Columnar
stepped
slab
During the construction of a slab foundation at a small depth, a solid base is created from monolithic reinforced concrete. The weight of the walls and roof is distributed evenly over the entire surface of the base. Such a design will be able to endure any movement of the soil. The disadvantage of the slab foundation is the high cost of installation and materials.
When deciding which foundation is more suitable for a basement floor on an uneven site, it is necessary to determine the level of elevation difference, as well as to study the type of soil in the area. Poorly thought out construction on a slope can eventually result in a collapse of the soil. To calculate the necessary calculations, it is better to invite specialists.
If the angle of inclination:
In the first two options, it is possible to erect a strip foundation. If it is impossible to level the surface or increase the angle of inclination, a tape-step type is erected. For large slopes, only a columnar base is suitable. But the pile foundation is appropriate for any slopes.
As for the type of soil, it is divided into:
The more moisture in the soil, the more it swells when it freezes, pushing the foundation out of the soil. Therefore, with complex soil, the base is placed below the freezing level.
During the construction of a strip foundation, one part of the base is plunged deep into the slope. The device of such a foundation is a costly undertaking, but if you plan to build a brick or concrete house, then tape version will be the best choice.
A pile foundation can be used for the construction of any type of building, whether it is a residential building, a garage or a bathhouse, as well as at any angle of inclination. With this option of building the base, it will be possible to use it for any purpose. The only drawback of the pile type is the impossibility of building a house with a basement.
Also, the choice of the type of foundation depends on whether you want to use the basement for arranging a basement, wine cellar, living room or garage to save space. Do not forget about the holding structures. They help prevent landslide processes when it is impossible to change the surface topography. Such designs for different type foundations on an uneven surface can be represented in the form of base plates and beams, pile structures and pillars, buttresses and seals, belts and facing walls.
To properly install the foundation with your own hands, you must adhere to a certain technological sequence. If you want to build a house of concrete or brick, the ideal option would be to choose a strip foundation. Monolithic strip foundation does not require large terms of arrangement. In addition, the construction of a strip base on an uneven surface is not very different from the construction of similar buildings on flat ground.
The bottom of the pit must be strictly horizontal. Before pouring, a pillow of concrete or sand is laid on the bottom. It is necessary in order to reduce the pressure on the ground. Before sheathing, a formwork is installed, rising above the ground to a height equal to the parameters of the basement. Moreover, on the sloping part of the site, the formwork will be of greater height. Next, the reinforcement is laid inside the foundation. Then you need to pour concrete.
It is necessary to pour continuously in layers of 20 cm. At the same time, it is important to correctly calculate the volume of concrete that will be needed during installation in advance.
The columnar foundation is suitable for light private houses. It can be made of monolithic reinforced concrete or factory-made concrete blocks. It is recommended to follow certain step-by-step instructions.
The pile foundation, which is the most economical, is suitable for steep slopes and unstable soils. Piles are screwed into the ground in such a way that their heads are on the same level. The process also consists of several stages.
As you know, the ideal place for the construction of a building is a flat, even area or a place with a slight slope. But what if you got a picturesque site with a significant slope? The easiest option is to make the features of the relief an advantage, not a disadvantage.
Building designs on sloping sites are different from conventional buildings. And if before it was necessary to develop each building in individually, now appeared turnkey solutions and recommendations, following which, you will cope even with such difficult work.
In the photo - even a small slope significantly affects the design of the house
You should know that the steepness of the slope is not measured in degrees, but in percentages. That is, the level difference in a section of 100 meters, which is 30 meters, is a slope of 30%.
And finally, depending on the relief, several main types of terrain can be distinguished:
If you have firmly decided that you will build a house on a site with difficult terrain, we advise you to consider several important points:
Due to all of the above factors, it is safe to say that the project of a house with a basement on a slope is the best option. The difference, as a result of which the price also decreases. The pit comes out much smaller, because only part of the floor is underground.
Advice!
You should not listen to those who claim that the basement almost doubles the cost of the project.
Properly calculated designs will slightly increase overall costs.
Consider several options that can serve as a kind of instruction for those who are going to build a building on a slope. Based on these examples, you can make your own version that will best meet your needs.
Such houses can often be found in northern Europe, they have a number of features:
As you can see from the plan, the floor is quite large, and you can easily place both a garage with a boiler room and a gym with a sauna on it. At your disposal are very large areas that can be used at your discretion - you can relax with friends, or you can make a workshop.
Everything here is imbued with the spirit of practicality and functionality - the entrance to the house passes through a cozy covered terrace. The axial room is a spacious hall from which you can enter the kitchen combined with a living room of a very interesting configuration, on the other side there are two bedrooms and a bathroom.
This level is small and very cozy - in such a bedroom you can relax from the hustle and bustle under the sound of rain, the bathroom increases convenience, because you do not have to go downstairs.
For those who do not need a second level and like one-story buildings, we suggest considering the second option. And if you have to dig a deep pit on a flat area, then the basement on the slope is much easier to make - only part of the level deepens.
In the first two articles, we talked about how the terrain features affect the construction of a house and how best to place your building in the existing landscape of the site. We conclude the series of articles with a story about how exactly the direction of the slope of the terrain affects the choice of a place for a house.
The southern slopes, of course, are more warmed by the sun. Therefore, you should try to orient the living quarters to the east, southeast or south. By placing the house on the southern slope, you can save resources for heating the building during the heating season. There is enough heat on the southeastern and eastern slopes. These directions are especially favorable for areas with a cold climate. For warm areas, such slopes are successful because coolness sets in here earlier. If you place the entrance to the house on the south side, then in winter there will be less snow and it will melt faster in the spring. The southern slope is less windy, and the sun warms more, illuminating the rooms and the terrace. Implementing, for example, a project two-story house with a garage, it is worth placing it on the southern slope closer to the eastern boundary of the land allotment.
It is not recommended to place houses on the northern slopes, unless we are talking about a site located in a hot climate. If it is necessary to determine a place for a house on the northern slope, then they build it in the middle, as close as possible to its western border.
The western slopes are known for being very hot in the afternoon sun, so they are also not recommended for construction. This applies to all climatic regions. If there is a plot for construction located on the western or eastern slopes, then the house should be located at its northern border at its highest point, placing all outbuildings below.
When placing a house on rough terrain, one should take into account the cold air currents that go down at night. An obstacle in the form of a wall of a house that has arisen in its path contributes to the formation of a “frost pocket” or “cold pocket”, the temperature in which will be 9 degrees lower than that of the environment.
If the house is planned to be decorated with a winter garden, then it is ideal to attach it on the north side. In addition to its main purpose, this room will serve as a thermal buffer. In addition, you can avoid the installation of sun protection devices and not be afraid that the plants will be exposed to direct sunlight. The open part of the winter garden is better to focus on the slope.
All these factors require additional financial investments. But in many cases, uneven terrain can inspire bold experiments to create a fun modern home. Competent organization of the site for construction and the location of the house and other buildings on the ground, taking into account its features, will make the site unique.
Building a house on a slope has many features. How to determine the slope of the site? How to place a house on a slope? What are the advantages of such construction?
Most good option for construction - a rectangular plot on a flat area. Features of the site dictate the conditions of construction. Do not be disappointed if you have to build a house on a slope - this can become a feature, a highlight of the project, and not a disadvantage.
Surface features (ravines, mountains, hills) are called terrain and are determined by the slope. The slope is defined as the height difference between two points projected onto a horizontal line. The slope of the surface is indicated by percentages, not degrees. For example, a rise of 20 m by 100 m horizontally is 20:100=0.2 (20%). The following types of terrain are determined by the percentage of slope:
For the construction of a private house, flat areas of the terrain or with a slight slope from the center are preferred. Such sites allow you to implement a project of any complexity, but more often they build model houses. If a slope is necessary to remove water, then it is formed with crushed stone, cement, about 50 cm high, and the width is made 1-1.5 m more than the foundation.
Sites with a low slope are suitable for buildings without foundations. Sometimes, for construction, soil is poured from the side of the slope.
Plots with an average slope can be used for buildings with a basement. In the basement, if access is possible, a garage can be placed. On such a site, soil is not poured, but, on the contrary, part of the slope is cut off. In such buildings, you need to seriously approach the waterproofing of the foundation and the basement.
In areas with a steep slope, construction will require an individual project, taking into account all the features of the surface. Of course, the layout of a house on a slope needs special preparation and additional expenses. But as a bonus, you get a lot of possibilities using the features of the surface.
Your site may seem to you a continuous unresolvable misunderstanding. In fact, there are only a few negative points:
You can build housing in several tiers, thus dividing the house into zones for different purposes. You can clear several parallel terraces to the width of the buildings and build a house in a cascade. The platforms are reinforced with slabs, beams or walls.
The location of the house on such terraces allows you to create a project with outdoor areas for recreation, winter gardens and a dining area under a canopy. This option is recommended already with a surface slope of more than 12 percent. It is also desirable to strengthen the site along the perimeter.
The best option is to build on the southern slope. Living quarters are best oriented to the east, southeast and south. So you will always be warm and light. In the cold season, less snow accumulates on the south side, and it melts faster. If construction on the western slope cannot be avoided, then it is better to place the house closer to the northern border of the site and, if possible, at the highest possible point.
There are two options for the location of the house on the site:
In relation to the house to the horizontal axes of inclination, parallel (a), diagonal (b) and perpendicular (c) placement on the site are distinguished.
In order not to create a shadow, buildings must be placed on a high point of the site (top). This solution simplifies waterproofing and drainage of water from the site. If your house is located in the middle of a slope and there are other areas above, take care of additional water drainage - a system of drainage pipes and ditches will help you.
If you plan to build on a steep rocky site, then you should use every flat site - building with terraces will the best option and help you make the most of the landscape. You can also decide this way: connect the individual buildings with transitions and beat it in the layout. At the bottom, place the entrance hall, wardrobe, above - the kitchen and dining room, then - the rest rooms, and at the top - the bedrooms (diagonal and perpendicular placement). Keep in mind that cold air moves downhill, so at night the temperature in the house can drop by 10 C - this is the effect of a cold pocket. To avoid cooling of the premises, a glazed conservatory or gallery can be arranged from the side of the top near the house.
For the rest, you should adhere to the current fire and sanitary construction standards.
Building a house on a slope- a responsible decision associated with many difficulties. But your reward will be a unique structure. Using the features of the site and competently planning the construction, you will build a non-standard architectural work. From a practical point of view, it is much easier to organize sewerage, irrigation and water drainage on such a site, and by building, taking into account the landscape, it is much easier to save on earthworks and arrangement of the territory. Perhaps you will only benefit by building a house on a slope.
Everyone who decides to build a house knows that the first step is to choose a site. The nature of the terrain determines the upcoming construction costs and the choice of the project of the future home. The most successful place for the construction of buildings are considered flat areas. Our ancestors also advised not to build in areas open to strong winds, to avoid mountains, lowlands and ravines. But if, nevertheless, you got a site that is far from perfect, then you should not give up - a complex relief can play a good service, it is only important to use it correctly.
The terrain refers to the structure of the surface - mountains, lowlands, hills, valleys, ravines, bulges and depressions, plateaus. The relief is determined by the slope - the fall of the surface, which is calculated by the ratio of the difference in height between two points on the terrain to the distance between these points projected onto the horizontal (see Fig.) or the tangent of the slope of the terrain line to the horizontal plane at a given point. The slope is measured as a percentage. For example, a rise of 15 m per 100 m of horizontal movement corresponds to a slope of 0.15 (15%).
Relief slope scheme
Flat terrain is considered if its slope is not more than 3%, a small terrain slope is from 3 to 8%, an average slope is up to 20%, a steep surface has more than 20% slope. The best in terms of construction are flat or with a minimum (up to 3%) slope towards the south, as well as those that have a minimum slope from the central part down on both sides (Fig.
Schemes of the most successful sites for construction with a minimum slope
Here, construction is as easy as possible: with such a relief on the site, various options for the location of the house and other buildings can be implemented.
Sites with a slope up to 3% can be used for building typical houses. Only small slopes are required to drain water from buildings - they are created by backfilling the soil, when using stones, gravel, cement, a slight slope is created from the house to the surface with a height of approximately 50 cm. The width of the backfill is on average 1-1.5 m wider than foundation.
If the slope is small - up to 7%, then it is suitable for the construction of buildings without basements. True, it is possible that at 5-7% of the slope it will be necessary to add soil from the piedmont part (see Fig.).
A site with a small slope of 5-7% with soil filling in the piedmont part of the slope
If the slope exceeds 8%, surface roughness can be used to build a basement. In such cases, they do not make a flat area, but create a lower floor by cutting out part of the slope array. This option is good for building an underground garage, if an entrance is possible from the side of the slope (see fig.).
A site with a cut-out part of the slope for the construction of an underground part (garage, etc.) with a slope above 8%
When the slope is steep and exceeds 15-20%, should consider developing special project house, using all the possibilities of a steep slope. The inconvenience of a slope can be turned into undeniable advantages if it is used to build a multi-tiered dwelling, which will make it possible to create separate blocks in the building: for example, guest rooms with their own entrance, workshop, summer kitchen, garage, pantry. If you have to build on difficult terrain, you need to turn the site into several leveled, flat surfaces. All buildings are placed on horizontal platforms, and their width determines the size of the buildings.
To do this, terraces are created, which are fixed with retaining walls, and connected by steps. Already with a 12% slope, buildings are best erected on terraces (see fig.).
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A site with a steep slope (more than 15%) equipped with terraces with retaining walls
A house built on terraces can be multi-level, have verandas on different tiers, balconies, patios. On the terraces there are also platforms, paths, recreation areas, gazebos and so on.
In the case of a significant difference in relief, more than 15%, it is recommended to install retaining walls so that the vertical seams in adjacent rows of stones do not match. Retaining walls are made of concrete slabs, boulders, bricks, timber, stones (see Fig.).
Terrace made with retaining walls of boulders with a slope of more than 15%
With a high wall height, the stones are fastened with mortar. The largest stones are located in the bottom row. To increase the strength of the retaining wall, all rows of stones are laid with a slope inward. The slope along the boundaries of the site is also fixed with stones, and granite, sandstone, limestone will serve as the best material for this.
You can fit a house into the area, make it one with the landscape, in two main ways - without changing or with changing the existing relief. If the first option is chosen, the house will organically fit into the surrounding landscape. However, in this case, it will be necessary to adapt its basement and underground part to relief conditions. When choosing the option of building a house on a flat area, the natural relief is disturbed, and planning work and a large amount of earthwork will be required to create harmony on the site.
In relation to the longitudinal axis of the house to horizontal lines slope distinguish between parallel, perpendicular or diagonal placement (see fig.).
The layout of houses in relation to the longitudinal axis of the house to the horizontal lines of the slope:
Scheme of parallel, diagonal and perpendicular arrangement of the house relative to the slope
Note: A residential building and other buildings on the terrain should not obscure the territory, therefore general principle the location of buildings on the terrain can be formulated as follows: buildings should be built on the highest and driest places on the site (see fig.).
The layout of the house at the very top of the slope
With this solution, the foundation is not so susceptible to moisture; easier to carry out earthworks; it is easier to design a basement floor, lay a sewer. When building buildings on a relief, it should be borne in mind that when the house is located at the highest place, all surface water can be effortlessly directed down the slope and used for watering plants. In the event that there are areas located higher up the slope than your house, it is important to ensure that water is drained using pipes or drainage grooves.
Buildings are best oriented to the south. It is good if the facade opens onto an open space, and a beautiful view opens from the windows. In the case when the house has to be installed on steep slope, options are known when it is placed literally in a mountain - the walls of the building are in close contact with the walls of a recess cut in the mountain, and only the facade is open and goes towards the slope (see photo).
A house built in a rock on a relief with a slope of more than 15%
If the house has to be built on a small plot close to a steep slope, then they use all the possibilities - the maximum approximation of one of the walls of the house to the mountain, the use of each flat area, the creation of terraces (see photo).
Other non-standard solutions are also possible: for example, a road along a horizontal terrace leads to the upper floor, which serves as an entrance hall or hall, a garage is located on the lower terrace, and the upper floor, which coincides with the entrance, is residential (see photo).
Non-standard solution for building a house on the slopes
The direction of the slope of the terrain is also important.. More heat is received, of course, southern slopes.It is desirable that the main living quarters be oriented to the south, southeast or east. If you place a house on the southern slope, this will save energy for heating it. The slopes of the southeast and east directions are also favorable for building a house - there is enough heat here (see fig.). These directions are good for placing houses in cold climates. They are also suitable for warm climates, as coolness comes here earlier. If the entrance to the house is located on the south side of the slope, then in winter time there will be less snow here, and in the spring it will melt faster. The winds from the south side are weaker, and the sun will shine on the terrace during the day and illuminate the premises. A house on the southern slope should be located closer to the eastern border of the site (see fig.).
The layout of the house on the southern slope
Unfavorable for the placement of houses are considered north slopes, the only exception is the hot climate. The best place for a house on the northern slope is closer to its western border, in the middle of the slope (see fig.).
The layout of the house on the northern slope
Regardless climatic conditions it is best to avoid building on western slopes, since in the afternoon they always get very hot from the afternoon sun. If the site is located on the eastern or western slopes, then the house is located at the northern border at the highest point, and all outbuildings should be placed below (see fig.).
The layout of the house on the western slope
When placing a house on uneven terrain, it must be taken into account that at night the cold air sinks down, and when an obstacle gets in its way, a so-called “cold pocket” may form, or in another way it is also called a “frost pocket”. If the obstacle in the way of cold air is a house, then the temperature there at night can drop 9 degrees lower than that of the environment (see fig.).
Scheme of the formation of a "frost pocket" when building a house on a slope
If the plans include the creation of a winter garden, then it can be placed on the north side of the house. In this case, in addition to its main function, it will play the role of a kind of thermal buffer, in addition, it will not be necessary to install sun protection devices that protect indoor plants from direct sunlight. It is also good if the open part of the winter garden faces the slope. You can read more about the arrangement of the winter garden in the article.
The layout of the house on the terrain relative to other buildings and objects
All of the above will incur additional costs. But uneven terrain can be a source of inspiration. Proper location of the house and other buildings, taking into account the characteristics of the area, will make the site unique. Houses built on relief can become real works of architecture.
In addition, there are objective positive aspects of building on an uneven site: slopes contribute to a non-forced, natural outflow of surface water that can be used for irrigation; you can save on earthworks when creating basement and basement floors, as well as a garage. So do not be upset if your site is located on uneven terrain - it is he who can contribute to the creation of a unique house architecture.
