Plastic windows are very popular. They protect the room well from cold and wind, and retain heat well inside the room. It is important to know how double-glazed windows are installed, because its correctness determines whether the window will function as planned. If a glass unit is damaged, it is quite possible to replace it yourself.
What do you need to prepare before installation?
Preparatory work plays an important role: without it, it will not be possible to install according to all the rules, which can lead to a violation of the window’s tightness.
If you have an old window installed and you want to replace it with a new product, you will need to start by dismantling it, then you will need to clear the opening of debris and level it if necessary. If you want to replace only a double-glazed window, it will be enough to carefully remove the damaged one from the frame: it is secured with special glazing beads. Remains of broken glass must be carefully removed. Wear gloves when working, as the edges may be sharp.
Before installation, it is necessary to take correct measurements to determine whether there is any horizontal or vertical displacement
Which design should you choose?
Installation begins not with installation, but with measurements. They must be accurate, otherwise the new design will not fit. If you are afraid of taking measurements incorrectly, invite a measurer. It’s good if it comes from the same company that will manufacture the double-glazed windows for you.
It is better to give preference to proven manufacturers whose product quality has proven itself well in the market.
The configuration is selected based on the number of sashes of the future window and the method of fastening. This determines how the glass unit will be attached. Usually there are two methods:
- Fastening through the frame in the same mounting plane.
- Using support reinforcement. Such fittings are already present in the frame and are placed there by the manufacturer.
Most often, the first method is used during installation, since it is easier to do it yourself, the weight of the structure is reduced, and installation takes less time. If the sashes are solid, you will need to remove the internal double-glazed windows. In the case of fittings, the scheme itself is a little more complicated, however, despite this, you do not risk damaging the double-glazed window during installation, accidentally damaging the frame or breaking the glass. You can install double-glazed windows hermetically, which is not always possible when self-installation the first way.
If the window is under warranty, you should not change the glass unit yourself: this will deprive you of warranty service. If the glass is damaged, contact the installation company.
How the window works
How is a double-glazed window installed?
The work takes place in several stages. First of all, you need to prepare the place: clean it, move the furniture away from it so as not to interfere with work; if the opening is uneven or there is debris, it needs to be cleaned and leveled using cement mortar.
Removing an old window
Preparation of the opening
After this, you can move on to preparing yourself. To do this you will need to remove the flaps. U Installation of a double-glazed window into the frame should not be carried out by weight; for installation, you will need to remove the glazing beads, for which you can use a chisel and a hammer. The work should be done carefully so as not to accidentally break the glass.
The beads need to be placed in the same place where they were previously, so it is better to number them right away.
The lower and side elements should be pulled out first, the top one last. The bead should fit tightly, but not tightly; if it does not fit into place, try another one: you probably have the elements mixed up. If the sequence is violated, the double-glazed window will not hold firmly, small gaps will form, violating the tightness of the window. There is no need to remove the frame to install the glass unit.
Installing the frame in the opening
After the first steps have been completed, you can proceed to the direct installation of the double-glazed window. Even with minimal experience, you will spend a little time on these actions. The installation is carried out as follows:
- In order for the installation of the frame to be smooth, special bars made of wood or plastic are placed at the bottom of the window. Most often, these items are sold in the same place where they are sold. plastic windows. The upper edges of the substrates should be horizontal; this can be checked using building level appropriate length or use for this purpose laser level. If the line is skewed, the window will also skew and it will not be able to function properly.
- After this, the structure is secured using anchor bolts or polyurethane foam. There is no need to rush to pull out the bars: this should be done two weeks after the window is fixed.
- To prevent the frame from bending, pegs should also be installed on the sides or in the center. They will hold the structure in an upright position.
- Check whether the glass unit is horizontal or not using a building level. If it is not level, you need to add pegs to level the structure to the desired plane. In order to find out whether the window is vertical, use a plumb line.
Installation of double-glazed windows
It is more convenient to fasten the frame from below, on both sides of the corners. After this, you can move on to other attachment points. If fastening occurs using anchor bolts, they should be tightened to the end only when the structure is perfectly level. Otherwise, there is a high risk of its deformation.
- Some structures are attached using the included metal ears: they already have holes for anchor bolts. Make sure that the hole drilled in the wall coincides with the hole on the eyelet, and metal element fit against the wall as tightly as possible: this will eliminate unnecessary cracks.
- After this, a window sash is installed, into which a double-glazed window has already been inserted, and the cracks are sealed.
Knowing how to install double-glazed windows, you can save a lot if you need to replace the glass and do the work yourself. This does not require any construction skills or the purchase of expensive tools.
If you or someone you know has previously used the services of companies installing double-glazed windows, then you know that installation can be normal and in accordance with GOST. The second option is more expensive, but if all the requirements are met, the quality will be much higher than in the first (you can read more about the standards in GOST 30971-02).
Consists of several stages.
Pay attention! Manufacturers do not provide a guarantee if the measurements were not carried out by their employees. At incorrect installation the windows will soon begin to freeze, and if even the slightest mistake was made in the calculations, the structure simply will not fit into the opening.
However, if you study all the intricacies of the process, then no difficulties will arise during installation. Moreover, this way you can save a decent amount of money.
Video - Installation of PVC windows according to GOST
Stage 1. Measurements
In most apartments there are openings without a quarter.
Pay attention! A quarter is an internal frame 6 cm wide (or ¼ brick, hence the name) that prevents the window from falling out and strengthens the structure as a whole.
If there is no quarter, then the frame will be installed on anchors, and the foam will be covered with special covers. Determining the presence of a quarter is quite simple: if the internal and external widths of the frame are different, then there is still a quarter.
- First, the width of the opening is determined (the distance between the slopes). It is recommended to remove the plaster for a more accurate result.
- Next, the height is measured (the distance between the slope above and the window sill).
Pay attention! The measurements must be repeated several times and the lowest result taken.
To determine the width of the window, two installation gaps are subtracted from the width of the opening. To determine the height, the same two gaps plus the height of the profile for the stand are subtracted from the height of the opening.
The symmetry and straightness of the opening are checked, for which a mounting level and plumb line are used. All defects and irregularities must be indicated in the drawing.
To determine the width of the drainage, add 5 cm to the existing drainage for bending. Also, the width of the insulation and cladding is taken into account (subject to subsequent finishing of the facade).
The dimensions of the window sill are determined as follows: the width of the opening is added to the size of the overhang, and the width of the frame is subtracted from the resulting figure. Regarding the offset, it should cover the heating radiator by a third.
Pay attention! measured after installation is complete.
Stage 2. Order
After measurements finished drawing should be taken to the window manufacturer, where all the necessary fittings. It is worth remembering that installation can be performed in one of two existing ways:
In the first option, you will have to pull the package out of the frame, insert it into the opening and install the glass back. In the second case, the entire structure is attached as a whole. Each option has disadvantages - if you pull out the package, it can; and vice versa, if the window is installed assembled, it can be damaged due to its heavy weight.
Prices for a popular line of windows
Stage 3. Preparation
This stage of installation begins only after delivery of the ordered windows. Released first workplace, all furniture is covered plastic film(there will be a lot of dust).
Step 1. If required, the glass unit is removed from the window. To do this, the glazing bead is slightly pryed with a staple and pulled out. First of all, the vertical beads are removed, then the horizontal ones. They must be numbered, otherwise gaps will form after installation.
Step 3. The bolts are unscrewed after the plugs are removed from the canopies. The handle is turned to the “ventilation mode” (in the center), the window is opened slightly and removed. All that remains is the frame with imposts.
Pay attention! Imposts are special jumpers designed to separate the sashes.
Then you need to make a marking for the anchors and make holes along it - two on the bottom/top and three on each side. To do this, you will need ø1 cm anchors and a drill of the required diameter.
If the material from which the walls are made is not dense (for example, cellular concrete), then fastening is carried out using anchor suspensions. The latter should be fixed to the wall and frame with hardened self-tapping screws (eight pieces for each).
Pay attention! To avoid the formation of a thermal bridge in the window sill profile, it should be filled the day before installation. This way the element will not freeze.
Stage 4. Dismantling work
This procedure is recommended to be carried out immediately before installing a new window. In most cases, the old ones are thrown away, so the structure can be torn out along with the fastening, and if necessary, the frame can be sawed.
Step 1. First, the seal and thermal insulation are removed.
Step 3. The window sill is removed and the cement layer underneath is cleaned off.
Step 4. Adjacent surfaces are treated with a primer material (by the way, many installers forget about this). In the case of a wooden opening, a layer of waterproofing material is laid around the perimeter.
Pay attention! Installation can be carried out at a temperature not lower than -15ᵒС. Polyurethane foam must be frost-resistant.
Stage 5. Installation of a plastic window
Step 1. First, wooden wedges are placed along the entire perimeter, a window is installed on them (this will make it easier to level the structure), only after this is it fastened to the wall. You can leave the backings - they will serve as additional fasteners.
Step 2. The absence of a support profile can be considered a gross violation of GOST standards, since it is not only needed for stability, but also makes it possible to install a low sill with a window sill. In the absence of a profile, they are attached directly to the frame, which violates its tightness.
The correct location of the stand profile is shown in the diagram.
Step 3. Next, the evenness of the window is checked in three planes, for which a mounting level and plumb line are used. It is typical that traditional bubble levels are not suitable for this due to insufficient measurement accuracy, so it is better to use.
Step 4. If the window is level, then it is secured with anchors. To do this, a wall is drilled using a hammer drill through pre-prepared holes in the structure (approximately 6-10 cm). The lower anchors are fixed (not completely), the evenness of the package is checked again, after which the remaining points are attached.
Pay attention! The final screed is made only after the final inspection. Do not tighten too much, otherwise the structure will “skew”.
Prices for mounting foams and cleaning gun cleaners
Polyurethane foams and cleaners for construction guns
Stage 6. Drainage
From the outside, the ebb is attached to the stand profile with self-tapping screws. The joints are carefully sealed with sealant to prevent moisture from penetrating into the structure.
The edges of the ebb are recessed several centimeters into the walls, having previously made indentations using a hammer drill.
Pay attention! Before installation, the bottom gap is also sealed.
Stage 7. Window assembly
After attaching the anchors, the glass unit is inserted back.
Step 1. The glass is inserted and fixed with glazing beads (the latter should snap into place, for which you can lightly tap them with a rubber hammer).
Step 2. The doors are opened and their tightness is checked. In the open position, arbitrary opening/closing of the sash cannot happen if the window is installed level.
Step 3. The assembly seam is sealed on the sides. Polyurethane foam will provide high-quality waterproofing and prevent glass fogging. Before and after sealing, the seams are sprayed with water to improve polymerization.
Pay attention! The seams are filled to no more than 90%, otherwise the structure will “lead.” If everything is done correctly, after drying the foam will protrude out a few centimeters.
Step 4. The perimeter of the window is glued with a special vapor barrier tape, and material with a foil surface is used underneath.
Stage 8. Installation of the window sill
Step 1. The window sill is cut so that it fits into the opening and at the same time rests against the lining profile. There remains a small gap (about 1 cm) for thermal expansion. Subsequently, the gap is hidden by plastic
Step 2. Wooden wedges are placed under the window sill. It needs to be laid with a slight slope towards the room, and then applied with something heavy until the foam dries. Additionally, the window sill can be fixed with anchor plates.
Video - Instructions for installing plastic windows
Conclusions
Now you know how plastic windows are installed, so you can safely get to work. The final check of all elements can be carried out only 24 hours after completion of installation (then the foam will have already “set”).
The described technology is also quite applicable to, although it also has its own nuances - such as, for example, installing a parapet to create a partition.
Find out how to do it correctly from our new article.
Plastic windows have long been common in city apartments or private houses, so it’s difficult to surprise anyone with them. They provide good sealing and thermal protection, but this is not the issue that interests many. People are interested in what types of plastic windows there are and how to install them correctly without the help of specialists. We will try to cover these questions in our article, taking into account all the nuances of the installation.
If you decide to install such windows yourself at home, then you need to choose suitable model for installation, and for this, you need to know everything about plastic structures.
Depending on the number of sashes, windows can be:
- single-leaf, with lateral or vertical opening;
- double-leaf, with one or two opening doors;
- tricuspid, with one, two or three opening doors.
According to the type of opening, windows are:
Depending on the number of chambers in a double-glazed window, there are:
- single-chamber, have two glasses with an air gap;
- two-chamber, have three glasses with two air gaps;
- three-chamber, have four glasses, with three air gaps.
Based on the shape of the window, they can be:
- rectangular shape;
- trapezoidal;
- arched and round;
- triangular.
There is another category of windows that combine several types of material. Otherwise, they are called combined windows. As a rule, they consist of wood, PVC and metal.
Advantages and disadvantages of plastic windows
If you cannot decide whether to install plastic windows or not, familiarize yourself with their advantages and disadvantages, then making a decision will not be difficult.
Plastic windows have the following advantages:
- tightness;
- soundproofing;
- perfectly retain heat indoors;
- absolutely harmless to humans;
- a large selection of shapes and opening mechanisms;
- long service life;
- resistance to atmospheric influences;
- simple care;
- large selection of colors;
- harmonious combination with all types of curtains.
To the disadvantages plastic structures can be attributed:
- Tightness, in addition to being an advantage, can also be a disadvantage, since it prevents the free flow of air into the room.
As you can see, the advantages of such windows are much greater than the disadvantages, especially since this can also be solved by regularly ventilating the room.
Window installation, stages of work
You have decided on the type of window unit, now it’s time to get down to work, which consists of several steps.
Stages of work:
- opening measurement;
- dismantling the previous window;
- preparing the window for the installation process;
- window installation.
If you have the financial means, you can order window installation in a special office, then you won’t have to do anything. But if the family budget is very limited, then you can install the window yourself, following our recommendations and sequence.
Window opening measurements
Measurements are carried out in several stages, but first, look at the drawing, which shows all the indicators of interest.
The opening is measured as follows:
When measuring a rectangular window, you need to know the width of the opening, from one extreme point of the internal slope to the other, and the height, which is equal to the distance between the top of the window and the window sill. These values are added to the thickness of the window sill. To find out the size of the window to be installed, it is recommended to use the formula:
Width = Opening width - 2*(gap size);
Height = Height of the opening – 2*(gap size) – height of the stand profile.
Measurements should be taken at several points in the opening, and when making calculations, focus on the smallest indicator.
The curvature of the opening is determined using a plumb line and level. Verticality is checked with a plumb line, and horizontality with a level. If you find serious violations, it is better to record them on the drawing. These notes will be useful to you in the future.
Ideally, the opening should look like an even rectangle in the drawing, then window unit fits into it perfectly.
If you plan to install several window units at once, then measurements are carried out for each window separately. You will not find two identical openings; at least the width will be different for everyone, but the height indicator should be approximately the same.
When positioning the window frame, one rule must be followed: it should be 2/3 of the width of the wall from the inner border. If the outer walls are sheathed with insulation, or this is just supposed to be done, then the window unit can be mounted even further, from the inner border of the window.
To measure the external ebb, you need to measure its length or take the opening width you have and add 50 mm to it for the bend. The width indicator for the external ebb is calculated as the gap between the installed plane and the outer edge of the wall; the interval for the protrusion and bend is added to these data. If the external walls are covered with insulation, then the width of this layer is also added.
To measure the window sill, it is necessary to determine its width, which is equal to the distance from the adjacent plane to the inside of the wall, but without taking into account the width of the window block. How much the window sill should protrude is determined in each individual case, but according to the rules, it should not extend beyond the radiator by more than 1/3. If it is located very close to the wall or even installed in a niche, then special holes for ventilation can be provided on the windowsill.
Slope measurements are performed after window installation. Before this, it will not be possible to accurately measure their length. The length indicator is calculated as the height of the opening taking into account cutting.
Measurements of the opening and a quarter
Such openings are typical for brick houses, and they are measured with some peculiarities. The opening is measured from the outside and is calculated using the following formula:
Width = width between quarters + 2*quarter overlap on frame (25–40 mm);
Height = height of the opening from the low tide point to the point of the upper quarter with the addition of an allowance for the upper quarter (25–40 mm).
When measuring such an opening, one should take into account cement screed, which is located under the ebb and window sill.
Measuring window blocks in a private house
To measure an opening in a private house, it should be taken into account that its size may be larger than it appears upon visual inspection. Slopes are often closed cement mortar or insulation. Therefore, before taking measurements, it is necessary to remove all excess.
This is also necessary to ensure that the installed window fits well into the window opening and does not accidentally fall out. It will not be possible to secure the window firmly in a layer of insulation.
Moreover, such an expansion of the opening will allow you to install a wider window in the room.
Selecting a window by installation method
If you have taken all the sizes, then you can go to the store and order required windows. There you can examine the opening mechanisms in detail and select best option for your room. But this is not the only thing that needs to be taken into account when choosing a window. The fastening method also plays an important role.
There are two types of installation:
- through the frame, then you have to remove sashes and double-glazed windows, even from fixed windows;
- on the supporting reinforcement, which is attached to the frame during its manufacture. This method is suitable for people who decide to install windows themselves, then you will not damage the double-glazed window. But it is very difficult to do this alone, since the window in fully equipped very heavy.
The preparatory stage involves the following work:
- frees up space near the window;
- disturbing furniture is removed;
- the floor and radiator are protected from construction debris;
- window structures are being prepared.
The last stage is also divided into several steps:
- preparing the window frame;
- foam filling;
- dismantling the old frame;
- installation of window frame.
Preparing the window block
Installation window design start with its preparation. Depending on which installation method was chosen, they begin to remove the double-glazed windows and hinged sashes from the window unit or do not remove them, leaving the window assembled. To remove a double-glazed window, you need to pry the glazing bead with a screwdriver and snap it out of the groove. Thus, you need to remove all four beads, starting with the vertical ones.
After removing the beads, mark them so that there are no gaps during assembly.
After removing the beads, tilt the frame forward, then the glass unit will freely come out of the grooves. You won't need it until you need it, so set it aside.
The next thing to remove is the swing doors. To do this you will need to disassemble the canopy. To do this, remove the special plugs and unscrew the clamping bolts. If this is a transom system, then to release the upper part of the window, you should turn the handle so that it is located in a central location, while the sash itself must be open for ventilation. All that remains is to pull out the hook from the lower canopy and the sash can be removed.
Holes for fastenings should be prepared along the entire inner perimeter of the frame. Their number depends on the size of the window, but on average, there should be three holes on the side parts, and two at the bottom and top. To drill them, you must use a metal drill. 8–10 mm anchors are used as fasteners; take this fact into account when selecting a drill.
If the window is installed on the provided lugs, then the window does not need to be disassembled. All you need is to attach the fastening elements to the frame and secure them with screws.
Foam filling
The foaming stage is not specified in GOST, and even experienced window installers do not always do this. But filling the substitution profile with one-component polyurethane foam is recommended to eliminate leaks warm air at the bottom of the opening.
To prevent this, interior space the substitution profile should be foamed with polyurethane foam. It is better to postpone further installation of the window for one day, this will allow the foam to completely harden and fill all the voids.
Dismantling the old frame
Disassembly of the previous window should begin on the day the new one is installed; you should not do this in advance. Decide right away whether you need the old frame. If you plan to use it further, at the dacha or somewhere else, then its dismantling must be careful. This process will be quite labor-intensive, so it is better to go with the second dismantling option. To make your task easier, the frame can be sawn and then it will be easy to dismantle. First you need to remove the swing doors and remove the glass so that you cannot get hurt. Next, the frame needs to be cut around the entire perimeter in several places. Using a crowbar or nail puller, you need to pry up each part of the sawn frame and remove all parts from the window frame.
The insulation located under the box also needs to be removed. You need to use a hammer drill to process the slopes or remove them completely if the windows are being installed in a private house.
The window sill is also removed using a crowbar. The lower part of the opening is processed with a hammer drill, removing 
thereby the cement substrate.
The dirtiest stage is over, now you need to start cleaning up construction waste.
The ends of the opening should be trimmed, cleaned of construction dust and the surface primed. This point is not always done by installers, so do-it-yourself installation has a great advantage.
If window installation is planned in private homes, then, in addition to the measures listed, it is necessary to lay a waterproofing layer around the entire perimeter of the opening, then you will protect your home and fasteners from moisture. To strengthen the opening, a wooden box is sometimes installed.
Window installation and methods of fastening it
Before installation work the lower end of the opening is covered with a special substrate. It is laid along the edge of the frame and the location of the impost, central post or in the middle of the opening.
You need to install the edge of the frame or the entire window on this substrate, depending on which window installation method you have chosen. The supports are not removed; the installed window will remain on them to make the task easier for the anchors.
The window is fixed on the sides with small blocks; they are hammered between the wall and the window frame closer to the top of the window so as not to bend the structure. After installing and fixing the window, check it with a water level to ensure it is horizontal.
Bubble levels have a small error when measuring horizontalness, so window installers advise using a water level.
If horizontality is violated, these errors are corrected by placing substrates under the frame. After horizontality, you need to check the window vertically. For these purposes, it is recommended to use a plumb line.
After the window has been checked for horizontal and vertical alignment, it can be secured with anchors.
Fastening the window through the frame
If you are interested in such a mount, then for work you will need a hammer drill, which you need to drill holes in the wall. In order for the installation of the frame to proceed without errors, it must first be installed, aligned horizontally and vertically, and anchored to the lower part of the window block. Next you need to prepare holes on the sides of the frame and at the top, and in the same way, attach everything with anchors. When the frame with attached anchors is ready for final fastening, check it again in all respects, and only then proceed to tighten all the fasteners. The main thing here is not to overdo it, otherwise you may deform the frame.
Window mounting on plates
If the window is being installed on special plates, then you first need to attach them to the frame. In appearance, these are metal plates with holes for anchor bolts. If you bend the plate into a step and press it tightly against the wall, you can start drilling a hole for fasteners.
The installation of the window begins from its bottom, and after each fixed plate it is checked for horizontal and vertical.
Drainage installation
There is a groove along the outer edge of the window into which you need to insert a drainage system. For a more durable fastening, screws are used to screw it to the frame. In addition, the installation site of the drainage system is carefully foamed, according to all the rules.
How to assemble a window
After installing the anchor bolts, you can begin to assemble the window block. If you disassembled the window yourself, then assembling it will not cause you any difficulties, since all the work must be repeated exactly the opposite way.
What to do:
- install the double-glazed window into the frame and secure it with upper and lower glazing beads;
- fix the double-glazed window with the side glazing beads and snap them all the way to hear a characteristic click. If you can’t do this with your hands, you can use a rubber mallet and, lightly tapping, snap the glazing beads into place;
- install sashes;
- after installing the swing blocks, it is necessary to check them for opening and closing;
- check the installed window level for compliance with all parameters;
- open the window alternately 45 and 90 degrees. In these positions, the swing door should remain motionless and should not close or open on its own.
When the window has passed all the checks, you can safely begin sealing the side gaps with foam. Remember that over time, foam can deteriorate, and ultraviolet rays are especially harmful to it, so it needs to be protected.
To do this, you need to stick a hydro-vapor barrier adhesive tape with inside and moisture-resistant membrane self-adhesive tape, with outside windows. In addition to the listed properties, the membrane tape also has vapor permeability, which allows you to protect the polyurethane foam from moisture and remove moisture from the inside.
The lower edge of the block also needs to be protected; for this, a waterproofing strip with a foil surface is used. When fastened, it will be completely covered by the window sill.
To ensure better adhesion of the foam to plastic surfaces, they need to be slightly moistened with water.
Window sill installation
The final stage of installation is the installation of the window sill. To attach it, you need to trim its edges so that it fits easily under the frame and fits snugly against the substitution profile. On the sides it should extend onto the walls by 5-10 cm. Its horizontalness is adjusted using pegs, and it is recommended to foam the hollow space with polyurethane foam.
To fasten the window sill, use 4x75 mm self-tapping screws, which secure the window sill to the frame in three places, on the sides and in the middle.
After the work has been done, the installation of the window is completed, but you should wait about a day for the foam to completely harden, then the sashes can be safely opened and closed. Using the same principle, you can install plastic balcony frames, taking into account the fact that the main emphasis will be on the parapet, which will need to be strengthened.
The installation of wooden windows is slightly different from plastic ones, so it would be wrong to use this technology.
The desire to improve the exterior of your home and save money on heating stimulated you to shop in hardware store and now you want to know how to install plastic windows yourself? That's right, because it is very irrational to pay a lot of money to professional builders for something that you can do yourself in just a couple of hours.
The technology for installing plastic windows is simple, even a child can handle it (if you support the structure in the opening). All you have to do is learn a few basic steps of this process and remember simple tips masters Now we will look at a typical installation of a plastic window according to GOST, starting with dismantling old frame and ending finishing slopes and installation of fittings.
How to get the necessary measurements to order a window?
Let's say you are just going to replace old and scary windows with new and thermally efficient ones. To do this, you will need to correctly measure the window opening so that you don’t have to sit and expand the walls of the house using a chisel and a hammer drill. The easiest option is to call a master measurer, which is provided by many construction companies and window sellers. It’s clear that this costs money, even if they don’t charge you a penny for it (the amount is already included in the cost of the window). The second option is to find a plumber or carpenter with straight arms at the entrance and supply him with 0.5 liters of Stolichnaya.
In fact, measuring and installing plastic windows with your own hands is a simple matter. First you need to get the exact width and length of the window opening without taking into account debris ( wooden frame, plaster, dirt). According to GOST, along the perimeter of the window structure we 20 mm should be left for thermal insulation, an additional 35 mm should be left for the window sill. That is, measure the width and height of the opening and tilt it 50 mm each– this will give you the necessary parameters for the new window.
There is also such a miracle of construction as quarter windows. What is it? A window with a small protrusion that increases heat loss around the perimeter of the window. Most often, such miracles can be found in houses made of foam concrete. Here we measure everything at the narrowest point and add 30 mm to the window width when ordering. 
The technology for installing windows involves fixing the frame not in the center, but with a recess of 30% of the width of the wall in depth (looked from outside the house). In fact, you can move it anywhere. The main thing here is to take into account the width of the future window sill and the ebb, because you can arrange it in such a way that the ebb will cover the entire window, but there is nowhere to even put a vase inside. Fastening plastic windows according to GOST requires adding another 50 mm to the width of the window sill and ebb, but here it all depends on the characteristics of your home. Please note: the radiator should only close halfway. 
Tip: keep in mind that when installed, the window sill and ebb will extend under the window by about 3 centimeters, as well as into the walls by 4 cm, so it is better to buy them with a length reserve of at least 70 mm and make them a little wider. You can always shorten it on the spot, the overpayment there is not much, but making something longer won’t work.
Dismantling old windows along with the frame and preparing for work
You measured the opening, bought everything necessary materials and are ready to install, but you are faced with one small problem that needs to be eliminated with a hacksaw and a hammer or - frame. There are 2 options for removing it - loyal and interesting. The first involves prolonged loosening, cutting and removal of the frame using a hacksaw, nail puller or pry bar. The second method involves active work with an ax or hammer.
Next, you need to remove the mounting foam, insulation, cement and other construction wonders that were used to secure the old window. A vacuum cleaner will not hurt, since installing windows yourself requires cleanliness for better adhesion of materials. You can blow out the dust with a compressor or immediately go through the sink, if possible.
Tip: it is much better to attach to a damp surface polyurethane foam, so heat loss will be much less after it hardens. It penetrates the structure of the material and does not interact with the layer of dust that covers the concrete or brick base.
Certainly, big advantage there will be moderately careful knocking out of the window so that load-bearing structure was not damaged. The smoother the window opening, the easier it will be for you to align everything and secure it.
Step-by-step instructions for installing plastic windows in a brick house
There is no need to strain your back - call 1 auxiliary worker who will help lift this difficult structure and support it while you perform all the necessary operations with the frame and double-glazed windows. Don't shoot protective film from the window until the installation is completed. If there are sashes, you can remove them, it will be easier, and then put them on after the frame is level. Now let's look at the step-by-step installation of a plastic window.
STEP 1: install wooden blocks on the bottom and sides. Using a hacksaw, cut wooden rectangles 20 mm high and 5 centimeters long (the dimensions may be slightly larger, depending on the desired gap). It would be advisable to secure the bars (glue, foam) so that they do not all fall out while you are placing the window in the opening. 
Important: wedges and bars must be installed near future anchors. This way, you can avoid frame deflection when installing plastic windows with your own hands, since measuring the pressure of the tool and tightening is almost impossible. You can screw an anchor or screw directly through wooden block, but no further than 30 cm from it.
STEP 2: insert the frame into the opening. First, simply place it on the bars, then adjust and move the wedges until the entire structure is level. Measure it not only horizontally along the window sill, but also vertically using a plumb line along the slopes.
STEP 3: make markings for anchors or screws. You need to insert a nail through the holes in the window frame and draw a mark. Next, take a drill and make holes around the entire perimeter of the window at the locations of the marks, drill directly through the frame, or you can remove it for convenience - at your discretion.
STEP 4: installation of plastic windows according to GOST. We install the frame in place, measure the technological indentations of 20 mm, according to building codes, then we “bait” the anchors without tightening them too much. If you wish to use anchor plates, then you just need to bend them so that they touch the window. If fastener protrudes 1 mm above the plastic - this is the optimal tightening. You can twist it a little harder so that it is flush with the surface. Check everything with a level after screwing, loosen or tighten the sides according to the readings of the device.
Correction: the instructions for installing plastic windows with your own hands are slightly different from those described above, if you have wooden house. Several operations are automatically eliminated, since fastening is carried out with ordinary long screws, which are screwed through the frame into wooden beams or logs. But they must be tightened with little effort and evenly along the entire perimeter of the frame so that it does not deform anywhere.
STEP 5: blow out everything with foam. Before installation plastic window sills It is necessary to fill everything around the perimeter of the window with foam, sparing no material (the excess can be cut off later). Make sure that it does not get on the window - it is difficult to wash. Wait 30 minutes and place the window sill under the window to a depth of 25 mm. Can be done minimum slope, let's say 3 degrees. Blow foam under the windowsill over its entire area so that there are no voids.
IMPORTANT: make grooves or grooves in the wall in advance for the window sill and remember that it is needed 8 centimeters longer than the window opening (it will extend 25 mm under the window and about 4 centimeters into the wall on the right and left).
At this step, the installation of plastic window sills ends; now you need to place 4 jars of cucumbers evenly across the entire window sill (so that it hardens evenly) and let the window rest from you for 3 days so that the foam finally hardens. You can put 3 bricks, it doesn’t matter, the main thing is to apply pressure of 10 kg or more. At an air temperature of +25, hardening will take 40 hours, but if it is cold and wet, then you should wait a little longer.
Do-it-yourself installation of ebbs and slopes on plastic windows
It is very easy to secure the ebb. We calculate its dimensions in exactly the same way as for the window sill, the only difference is a large slope from the window, so that the water does not linger and disappears immediately after entering. Fastening can be done with polyurethane foam or ordinary self-tapping screws; the ebb is screwed to the stand profile (the one on which the entire window stands). Do-it-yourself installation of the low tide can be considered complete; nothing else is needed, except to seal the gap between the low tide and the plastic with silicone if desired.
Now we smoothly move on to the slopes. They must be beautiful and thermally efficient, so we (and not only us) recommend using sandwich panels for this purpose (you can use drywall - it’s cheaper). If you think that it is very difficult to install a slope on a plastic window with your own hands, then you are mistaken. We take tape and foam. We blow out the entire sidewall or top with foam, lean the slope and tape the sandwich panel to the walls e. Seal the seam between the window and the panel with silicone or another miracle device that prevents heat loss and does not allow moisture to pass through.
Now all that remains is to install the fittings and blinds on the plastic windows with your own hands and you can start using the structure in 30 hours. It is necessary to wait until the polyurethane foam polymerizes and does not deform the sandwich panel and other elements of the plastic window.
And by tradition, we suggest watching a good video of installing a window with your own hands, it describes the process in detail and clearly shows all the fasteners:
