BUILDINGS TO STAND THE TEST OF TIME

[size=15pt][color=#000000][font=宋体]               BUILDINGS TO STAND THE TEST OF TIME[/font][/color][/size]
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Bulldozers are a thing of the past. Today the main aim of the urban planner is to retain town centers with all the history they have to tell. But their intention is not solely motivated by a fervent belief in ecological principles: They also want to avoid, above all, anything that might tear out the head of the community.
But it is not only the picture-postcard half-timbered houses or the buildings of historic worth that should be saved. Many of the housing projects and buildings erected during the early post war years that, at first glance, look as though they should be razed to the ground, can be adapted to today's standards and made attractive. This approach is ecologically friendly and saves precious natural resources, and is preferable to demolition and erecting completely new buildings. If it is impossible to avoid demolishing older buildings, such demolition should be carefully organized and planned so that the undamaged parts of the structure can be preserved and reused. As a matter of principle one should keep in mind that any process of redevelopment should avoid any building's unnecessary alterations or damage to the underlying structure and fabric of the building, because this will inevitably increase redevelopment costs quite substantially.[/font][/color][/size]
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[font=宋体][size=3][color=#000000]Anyone living in an older house or apartment built prior to the 1940s is quite probably living in a reasonably healthy environment because up until that time predominantly natural building materials were used, and buildings usually did not suffer from indoor air quality problems because they were not at all air tight. An important exception to this, however, would be the widespread use of lead paint. Toward the end of the 1950s the era started when everything had to be labor-saying and low-maintenance. Thus, we saw the advent of insulating foam, mineral fibers, gloss paints and varnishes, plastic window frames - and, of course, all the attendant problems that are still with us. Restoration can very often be a boon for the environment in so far as the undesirable materials and qualities of a building can be removed.[/color][/size][/font]
[size=14pt][color=#000000][font=宋体]The condition of older buildings in the United States[/font][/color][/size]
[font=宋体][size=3][color=#000000]The housing stock in the United States in total amounts to approximately 11O million units today, with 35% in multiple dwellings; 25% is more than fifty years old. About 10% or 1 I million units of housing lie vacant; 68o/0 are single-family buildings of some sort and 32% multiple unit. It is estimated that an investment of over $700 billion would be needed to renovate and repair the existing aging housing stock. The greatest need for expenditures in renovations are for buildings built after 1945 and before 1970.To house the "baby boom" huge volumes of housing were built at very low cost and often with inferior materials and sub standard workmanship. In addition, these buildings were not subject to the 1972 National Fire Code which required multi-story buildings to be fitted with automatic fire protection systems, nor were they subject to modern energy codes. One other factor is the National Historic Preservation Act passed in the 1970s which established the National Register of Historic Sites and significant tax credits for investments in renovating buildings which were placed on the Register. When the tax credits were dropped in the late 1980s, the interest in historic preservation diminished greatly because meeting the demands of the Historic Preservation Requirements for maintaining the historic character of the buildings often added great expense. However, buildings which were built in the 1970s are also in need of substantial repairs. One reason is that many of the energy conservation methods employed at that time caused severe damage to the building envelope, or air quality problems which have resulted in the phenomenon known as Sick Building Syndrome. Significant problems also surfaced due to the use of new fenestration (window) systems especially in "curtainwall" building types. Apart from the need for wide-ranging maintenance work the insulation of the buildings has to be improved. The generously proportioned and stuccoed town houses built at the turn of the century with thick external walls do in general conform to modern requirements. By contrast the houses erected in the 1920s had far thinner walls. Even though concrete was being used more and more in the construction of cellars, adequate damp proofing tended to be the exception rather than the rule. Post-war buildings erected in the 1950s have, in the main, extremely thin external walls well below the norms for thermal insulation and soundproofing. On buildings erected in the 1960s and the 1970s damage to concrete occurs more frequently, mainly as a result of poor-quality reinforcement, and there are also problems with moisture and with heat bridges on balconies. Buildings erected during the next two decades now have problems with prefabricated concrete elements and the incorrect fitting of what were at that time completely new insulation systems, all resulting in serious structural damage, [/color][/size][/font]
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[color=#000000][font=宋体][size=3]1: ([/size][size=14pt]A reflection of the times [/size][/font][/color]
[font=宋体][size=3][color=#000000]War, destruction and crises are mirrored in the age of the buildings; but we can [/color][/size][/font]
[font=宋体][size=3][color=#000000]Also read the reconstruction and economic prosperity in the buildings around us)[/color][/size][/font]
[color=#000000][font=宋体][size=3]2: ([/size][size=14pt]A house with a history[/size][/font][/color]
[font=宋体][size=3][color=#000000]Old houses frequently have many stories to 1elL.Their facades Lend character to the surroundings. Yet it is net just their maintenance that is expensive; frequently they waste large amounts of energy or they may contain toxic substances dangerous to human health. This makes restoration more expensive. But the maintenance of the historical structure is worth the effort, as can be seen from this old building in Dortmund, Germany.)[/color][/size][/font]
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3: ([/color][/size][size=14pt][color=#000000]The magnificent 1920s[/color][/size][/font]
[font=宋体][size=3][color=#000000]At the beginning of the century buildings were really sorry solidly build .as can be seen from this garden estate in the Ruhr area. Cheaper and lesser quality construction did start in the 1920s.but most buildings erected during this period at least were given massive walls and. in general architecture perfectly suited to its surroundings. But basements of such buildings are almost without exception. Damp Renovation tends to concentrate primarily on the plumbing the windows attic improvements and roof insulation.[/color][/size][/font]
[color=#000000][font=宋体][size=3]4:
([/size][size=14pt]A shortage of housing [/size][/font][/color]
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Most of the housing in Germany was erected after the war. It was above all in the 1950s that poor qulity materials were utilized. Walls were too thin and so houses build during this period wasted a great deal of energy. The most important repair work, However. Is the installation of better insulation for the external walls and the roof. )[/font][/color][/size]
[font=宋体][size=3][color=#000000]5: ([/color][/size][b][color=#000000][size=14pt]More money than good sense [/size][/color][/b][/font]
[font=宋体][size=3][color=#000000]The 1960s enjoyed the emergence of an economic boom, And in Germany. More and more people fulfilled their dream of owning a bungalow, Yet the style of building so admired while on vacation abroad was hardly suited to central Europe: A flat roof would soon start to leak and let in cold draught. The walls were far too flimsy. And the huge energy, The wonderful new and impressive-looking home soon became a white elephant.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]6:([/size][size=14pt]The solution depends on the type of construction[/size][size=3] [/size][/font][/color]
[font=宋体][size=3][color=#000000]The use of prefabricated concrete was popular in the 1970s because buildings should be built more quickly and cheaply. But the concrete was often poorly reinforced and sealants made with toxic substances were typically used in the concrete sections. More and more use was made of hazardoys materials such as asbestos fireproofing and insulation. There were also heat bridges causing energy loss and moisture problems in many of the buildings. All of these factors contributed to serious problems in this type of housing)[/color][/size][/font]
[size=14pt][color=#000000][font=宋体]Refurbishing historical buildings and half-timbered houses[/font][/color][/size]
[font=宋体][size=3][color=#000000]In Germany, there are approximately two million buildings under a preservation order according to German government estimates. This figure includes sculptures and ruins, and the actual number of such buildings is more likely to be between one million and one and a half million. 40% of these buildings of architectural importance located in the old Federal states and 90% of them in eastern Germany are in chronic need of repair. The number of half-timbered buildings is estimated to be two million, And of these 79% were built before 1870. Only 3% of them were[/color][/size][/font]
[font=宋体][size=3][color=#000000]erected after 1919 There are no half timbered houses in the United States but a number of timber-frame structures (similar to half timber but with the structure built completely interior to the exterior cladding, usually of wood boards) built from 1656 up to the late 180Os exist According to government statistics, the average life span of a conventionally built stud house is about 75 years, whereas the life span of a timber frame house is at least 300 years.[/color][/size][/font]
[font=宋体][size=3][color=#000000]Damage to half-timbered and timber-frame houses is due mainly to a lack of maintenance or improper care of the substance of the building and to so-called "experiments" with modern materials and methods. For example, a frequent mistake is the attempt to weather proof a facade by means of resurfacing and applying multiple layers of plaster and various different types of coatings over the woodwork. Another improper solution is to simply fill and grout the cracks and joints between the woodwork and the plaster with silicone. In many cases, the thermal insulation is also installed incorrectly, which makes the problem worse. Behind any facade that has been improperly insulated and the exterior skin sealed in some way, wood rot is inevitable. [/color][/size][/font]
[font=宋体][size=3][color=#000000]Half-timbered buildings and those under a preservation order have one feature in common: Whatever is done to improve the building and to repair it must not in any way have a detrimental effect on the physical appearance of the building. This in itself adds to the problems, particularly when thermal insulation has to be installed. External thermal insulation of any kind is virtually out of the question, because the facade with its decorative surface and exposed timbers would be hidden. There are now, it is true, all kinds of cornices, stucco work and facade moldings made of plastic and even, more recently, of recycled materials, which can be used to restore or rather to imitate the look of the original facade by application over the new layer of insulation However, this approach does not really have much in common with the true principles of historical building preservation and certainly not with ecological building. In such a situation all that can be done is to install insulation inside the building. It demands careful detailing and painstaking installation, however, or condensation could occur resulting in damage to the structure of the building and problems with mold and mildew inside the building. It is for this reason that biological building materials come into their own, They can frequently be used for internal insulation without installation of a moisture barrier. A moisture barrier is usually used to prevent entry of moisture from the exterior causing condensation somewhere in the wall cavity in renovation projects, however, there is no general rule, and so the architect must search for the best solution for each individual case. Furthermore, it is almost impossible to install a totally impervious moisture barrier, because there are so many gaps in the joists and floors of a half-timbered building. If the timbers are to be repaired, it is advisable to adhere to the local traditions and use either clay filling or small bricks. The addition of the internal insulation material must cover the timbers preventing a thermal bridge. The best answer might well be to use a mixture of straw and clay, of which one of the most useful properties is its ability to absorb moisture and to release it: It has the added advantage that it does not clash with the wood. A further method is to nail light insulating boards made of wood-wool or wood fiber onto lath-work and then to pack the spaces with mortar, taking care to ensure that a capillary connection will still remain to the outside allowing moisture to escape.
A firm in Celle, Germany specializes in insulation for half timbered buildings and has developed a material consisting of clay, straw, cork, and diatomite. This mixture can be sprayed in thin layers or molded into thicker strips and compressed behind the timbering. Within three weeks the mixture is as solid as a rock. The material has the same properties of absorption and diffusion as the existing clay or brick, and can, for this reason, lie directly on the surface that is to be insulated with out a moisture barrier, Determining which method is finally chosen will depend on the particular building and has to be thoroughly reviewed by the architect, if the interior of the building is generously proportioned without a large number of separate rooms, having numerous openings and galleries, ventilation will be more efficient and less moisture will penetrate and therefore damage the walls and the structure of the building.[/color][/size][/font]
[color=#000000][font=宋体][size=3]1: ([/size][size=14pt]The sheer beauty of half timbering[/size][/font][/color]
[font=宋体][size=3][color=#000000]Half timbered houses such as these in Minden are not so difficult to restore, because they are erected in separate units Nonetheless, great skill and[/color][/size][/font]
[font=宋体][size=3][color=#000000]considerable knowledge of building traditions are essential The insulation and facade restoration are particularly difficult and painstaking But insulation of this type is very expensive Recently a triple Layer thermal insulation material made of wood fiber boards has been developed and it has been found that it is highly efficient at relainin8 moisture inside the insulation and releasing it inwards Such material has been found to be ideal for half timbered buildings.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]2 :( [/size][size=14pt]Decorative facades[/size][/font][/color]
[font=宋体][size=3][color=#000000]The facades of this house erected in Munster in the 1870s are the work of a genuine artist and they cannot possibly be insulated from the outside. Even insulation[/color][/size][/font]
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On the inside could have disastrous consequences if not executed with expert knowledge and skill.)[/font][/color][/size]
[size=14pt][font=宋体][color=#000000]The most common mistakes while repairing a half-timbered building[/color][/font][/size]
[font=宋体][size=3][color=#000000]While repairs and improvements are being carried out, what is often overlooked is that the interior walls in a haft-timbered building also serve structural and load bearing functions, even though the timbers themselves have a relatively small cross section. If walls are removed to "modernize" the interior or to combine several rooms into one, the beams may start to sag or the walls to buckle, because the timbering has started to move. What is also frequently overlooked is that the function of the wall-to-wall beams is to stiffen and retain the walls once the beams have been sawn through, for example to build a staircase, the entire structure of the building could change shape consider ably and be undermined. The same would happen if diagonal struts were removed: Their purpose is to stabilize the frame construction consisting of timber pillars and beams. The struts are often sawn through out of ignorance in order to fit larger windows, In addition, it is very important to heed the warnings against removing old filling material entirely from the timber, as is all too frequently recommended, Over the pas sage of time the filling has taken over a load bearing function, and if it were to be removed, the beams would very likely give way under the weight that they alone have to bear as a result. It is likely that the building would' then break apart. Once the new timbers have come to rest, it is probable that the newly installed stonework will no longer fit properly [/color][/size][/font]
[size=3][color=#000000][font=宋体]In fact, modern concrete blocks should never be placed between the wooden beams. This particular material is, no doubt, an excellent insulator and can easily be cut to the correct shape, but aerated concrete absorbs water, unless it is completely protected even from a driving rain. This is extremely difficult to do, because there are so many gaps between the beams. The water is transported to the edges of the beams. which then star[ to rot, The best solution is to use stones for the backfilling. A thinner second wall of aerated concrete behind the thin frame wall will not ruin the wall's appearance, nor will [t cause any problems with the building's equilibrium. Again, there must be a mortar layer between the external wall and the backfilling, or, alternatively, adequate ventilation of the entire building facade so that any condensation might dissipate. The unfortunate truth is that most attempts to restore a half-timbered building are disastrous. Instead of seasoned oak timbers new softwoods are very often used. They are usually not given a chance to dry out properly and will continue to con tract and warp, thus causing cracks and subsidence. Sometimes there are even cases of rotting and diseased woodwork being covered over with boards and paint without any effort to find and remove the cause. Measures such as these merely create the illusion of stability in the building, and sooner or later such superficial and careless work will have a disastrous effect on the entire structure. And it is by no means just the interior insulation that needs the utmost care and expert planning: The incorrect external insulation of a half-timbered building can do irreparable damage as well, if the easy way out is taken by covering the facades with cladding or plastic bricks, the woodwork will simply disintegrate.
In Germany people were frowned on for many years if they did not live in a "real" brick house. Even as early as in the biedermeier period there were types of cladding that imitated stonework, After the Second World War damaged half-timbers would very often disappear behind thick layers of cement facing: It is, therefore, hardly surprising that the primary timbers and the supporting columns would start to rot within a few years. This resulted from the application of materials such as imitation tiles and asbestos cement boards, if they were applied to the original fa[/font]ç[font=宋体]ade without any ventilation. The moisture remains on the wall, the wood rots and will be eaten away by wood ticks and borers. Builders' merchants, too, sell a wide range of materials manufactured explicitly, so it seems, with the intention of simplifying the process of disfiguring any building of historical or architectural importance that might be in need of repair. Just some examples of pseudo historical kitsch now available are imitation window muntin bars, bull's eyeglass usually placed where they do not belong. cast aluminum and fiberglass doors made to look like real wood, faux copper guttering and lamps with scroll mountings. It is quite evident, therefore, that we need to be reminded of the value of skilled craftsmen. A great many architects and civil engineers have never learned that conservation and building are inseparable, and so it is essential to seek advice from experts who have the necessary experience and knowledge.[/font][/color][/size]
[color=#000000][font=宋体][size=3]1: ([/size][size=14pt]Half-timbering requires a craftsman[/size][/font][/color]
[font=宋体][size=3][color=#000000]There are probably two million half-timbered buildings in Germany, all bearing witness to a long tradition of craftsmanship. The house shown here with its magnificent gable is to be seen in Schieder-Schwalenberg. But because no more half-timbered buildings have been erected for many years, there is hardly any one with the skills and experience to ensure upkeep, It is for this reason that irreparable damage can be done to buildings of this type; less work will have a disastrous effect on its entire structure including the interior.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]2: ([/size][size=14pt]Healthy surroundings[/size][/font][/color]
[font=宋体][size=3][color=#000000]Buildings of clay, such as this half-timbered house, can be very healthy to live in. At the same time a house like this is the embodiment of the best traditions of sustainability, because it has been constructed using local natural and renewable materials. For this reason expert restoration is certainly worthwhile[/color][/size][/font]
[color=#000000][font=宋体][size=3]3: ([/size][size=14pt]Applying straw to a timber[/size][size=3] frame[/size][/font][/color]
[font=宋体][size=3][color=#000000]Straw matting is an excellent means of insulation and a base for plasterwork. But walls of this type rarely meet with today's requirements as far as adequate insulation is concerned.)[/color][/size][/font]
[font=宋体][size=3][color=#000000]4: (Following the traditional methods [/color][/size][/font]
[font=宋体][size=3][color=#000000]It is the responsibility of certain young craftsmen today to gain the necessary skill and know ledge to ensure the preservation of the ancient art of building half timbered houses so that it is not lost. The walls of this house in Kescheid are being repaired with a mixture of clay and straw, as was the tradition when the house was originally erected.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]5: ([/size][size=14pt]Best obtained on site [/size][/font][/color]
[font=宋体][size=3][color=#000000]Clay suitable for house building is often to be found on the site itself. But if the excavated material is unsuitable, there are always companies specializing in the various earth materials)[/color][/size][/font]
[color=#000000][font=宋体][size=3]6: ([/size][size=14pt]A romantic street corner[/size][/font][/color]
[font=宋体][size=3][color=#000000]These houses in Minden (above) and in Hattingen (left) have a particular charm and are an expression of romantic traditions in Germany. Tourists find them particularly appealing.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]7: ([/size][b][size=14pt]Kitsch and false economy[/size][/b][/font][/color]
[size=3][color=#000000][font=宋体]Lt is an unfortunate fact there are too many examples like this one of how not to restore old buildings. The old wagon wheels are merely kitsch and the windows (below) are in very bad taste in that they are historically out of place as is the gallery in the renovated barn structure in the background. The facade cladding is not only an example of lack of taste bur of false economy as well (right): The work has not been done expertly and the timbering beneath the cladding will be seriously damaged.
ultimately causing considerable expense to correct the problem.) [b][size=14pt][/size][/b][/font][/color][/size]
[size=14pt][color=#000000][font=宋体]Remediation of moisture problems[/font][/color][/size]
[font=宋体][size=3][color=#000000]Damage caused by moisture is a serious and recur ring problem in older buildings. Leaky roofs, poor roof drainage, wall cracks and bad insulation all can allow unwanted moisture to gain access. Problems can also be caused by moisture saturation. This can occur in the foundation or basement walls and any walls in direct contact with the ground. Renovation and repairs are likely to be exceedingly difficult and expensive. Walls can absorb as much moisture from the subsoil as they do rain or ground water. Even the smallest capillary in a wall will transport water upwards and cause damage to the ends of wood rafters or beams embedded in or bearing on the wall. Over the years, the footings of buildings have been protected from moisture by various means. From around the turn of the century up until the present time it has been common to apply a portland cement plaster facing called parting to protect wall surfaces. Historically, cellar floors were left unprotected from subsurface water, and as a result moisture did penetrate the building which was the best way for people to store their provisions. The moisture was prevented from spreading upwards into other parts of the building by constructing high wall bases (sometimes called a water table) so that the floor joists would be well above the level of the topsoil. In this way there would be enough room for moisture to evaporate, particularly as the cellar would be continually ventilated by the unglazed windows Later, It became the practice to apply damp proofing onto many wails, normally o roofing felt, or sheets made of lead or tiles. The cellar floor, however, still remained damp. If building improvements of some kind were later made to the cellar, and damp proofing plaster to be applied to the outside surfaces of the walls, or new, tightly closing windows fitted, the evaporation process would be stopped and the resulting accumulation of moisture would start to do its damage.[/color][/size][/font]
[font=宋体][size=3][color=#000000]Enormous stains would then appear on the wails indicating the extent of moisture penetration. At this point the only cure is to excavate the entire perimeter of the building and undertake measures to damp-proof the walls from the outside. Of course any structural damage already done would have to be repaired. The most suitable material for accomplishing this, despite its limitations, is cement grout. Other materials which can be used include a variety of bitumen-based damp proofing products which are painted on, or a variety of plastic or bitumen membranes usually referred to as a water stop and a material called bentonite which chemically reacts[/color][/size][/font]
[font=宋体][size=3][color=#000000]with water and seals any cracks when exposed to it None of these materials is ecologically acceptable, but they are better able to accommodate movement of older stone or brick foundation walls than cement grout, which becomes brittle and will lose its integrity once the wall settles or shifts to any degree. At the same time it is advisable to attend to the thermal insulation in this part of the building by improving the perimeter insulation. Suitable materials in this case include expanded glass, a waterproof insulating material manufactured from recycled glass fixed to the building with bitumen, or rigid fiberglass sheet insulation both of which do not lose their insulating properties when saturated, as batt or open cell foam insulation would do. Once the excavation has been completed, a layer consisting of ballast or gravel is required for drainage and to prevent water collecting close to the walls. There are also new drainage membranes which are made of EPDM rubber or PVC (not recommended for ecological reasons) which are designed specifically for this purpose, The rate of absorption or seepage through a wall is proportionate to the force of hydrostatic pressure, which can be extremely great unless there is good continuous vertical drainage at the face of the wall to alleviate it, In order to insulate and thus protect the basement floor and the foundation walls against rising moisture, the walls must be lifted up meter by meter or horizontal sawcuts made above the affected area. A metal or plastic water stop membrane or a bitumen layer must then be inserted into these narrow gaps. If the gaps in the walls are fairly sizable it is safer to use special machinery to insert high-quality steel sheets. The alternative to the lengthy and expensive method of splitting the walls is to use the injection method Special chemicals, or sometimes paraffin oils, are injected through carefully drilled holes in the walls so that the capillaries are filled, thus forming a zone into which water will be unable to penetrate. This method is not known to be harmful to health or to the environment, but some experts still doubt whether it can be effective. In addition, it will not work with
uneven or extremely damp stone masonry Damp-proofing from inside, for example by means of a specially formulated wet use plaster, will make the wall look dry, but the moisture will nevertheless continue to rise in the wall until it finds a surface on which it can evaporate. The moisture will ultimately end up precisely where it is least wanted.[/color][/size][/font]
[color=#000000][font=宋体][size=3]1: ([/size][size=14pt]Damp-proofing a cellar[/size][/font][/color]
[font=宋体][size=3][color=#000000]Moisture rising from the subsoil presents a danger to a great many buildings Unless measure are undertaken to stop rising moisture, the walls will probably weaken and rot Water from the surrounding soil makes the cellar damp If this room is to be used for anything other than storing provisions, drainage is essential as well as insulation of the exterior cellar walls (perimeter insulation)[/color][/size][/font]
[color=#000000][font=宋体][size=3]2: ([/size][size=14pt]Precast Concrete Construction[/size][/font][/color]
[font=宋体][size=3][color=#000000]This type of housing development in Leipzig is still common in areas such as eastern Germany People like living in these apartments; in contrast with other enormous developments, good neighborliness is still common. Nevertheless, some of the buildings are in urgent need of repair even though they are not that old. The most serious problems are with the sealing between the slabs, the roof and the windows)[/color][/size][/font]
[size=14pt][font=宋体][color=#000000]Problems with 1950s buildings[/color][/font][/size]
[font=宋体][size=3][color=#000000]Environmentally harmful and unhealthy materials
such as polystyrene foam and mineral fibers have been used pervasively for insulation Today environ-mentally benign materials such as cellulose from wood by-products and recycled paper, and other renewable materials such as reeds or cork can be used for this purpose, When it is not necessary to preserve the existing building facade which is inadequately insulated in its original form, it is possible to build a new facade in front of the original. As little as four and a half inches of added insulation will attain a u-value of 0.05 (k-value of 0.30) or less for the walls a completely acceptable heat-loss coefficient for a rehabilitated older building.[/color][/size][/font]
[font=宋体][size=3][color=#000000]A recurring problem with post war buildings is the water leakage through the buildup roofing typically used on a flat roof It is now considered preferable to erect a conventional sloped roof on top of the old roof structure including the desired amount of added insulation, instead of trying to repair the existing roof But this is extremely expensive and may not be feasible due to structural limitations. Problems may also arise if the entire estate consists of houses with flat roofs: The new roof might infringe on the other buildings' access to natural light or it might simply look out of place. For these reasons a better solution may actually be to grass over the roof. A specially developed drainage membrane needs to be laid down before laying the grass which resolves any water leak age problems previously present. The membrane itself is shielded from damage caused by ultraviolet (UV) radiation by the natural vegetation which also insulates and keeps the building cooler during the summer by reflecting most of the light and heat from the sun. The green roof will also contribute consider ably to the local micro environment by converting CO2, manufactued8 oxygen, reducing runoff and reducing the ambient local temperature in areas with lots of paved surfaces. Depending on the climate, there may be a requirement for a thicker layer of growing medium (lightweight soil) to protect the grass planted. It is also important to have the design reviewed for structural soundness before going ahead with a green roof project. A recently completed corporate eco office building for The Gap in San Bruno, California was given an undulating green roof evoking the surrounding landscape. manufactued oxygen, reducing runoff and reducing the ambient local temperature in areas with lots of paved surfaces. Depending on the climate, there may be a requirement for a thicker layer of growing medium (lightweight soil) to protect the grass planted. It is also important to have the design reviewed for structural soundness before going ahead with a green roof project. A recently completed corporate eco office building for The Gap in San Bruno, California was given an undulating green roof evoking the surrounding landscape. The green roof feature was estimated to reduce the building's annual operating and energy costs by $28,000 and will pay for itself in eleven years.[/color][/size][/font]
[color=#000000][font=宋体][size=3]1 :( [/size][size=14pt]Boldness in design pays off [/size][/font][/color]
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The frontage of this low-energy house before and after its renovation: all that `shows extemally that the building has been improved quite drastically is the
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[font=宋体][size=3][color=#000000]Newly designed stairwell .the old house stands in a part of the city which contains several large residences and its outer wall, cellar and roof were treated with thick insulating material. A new ventilation system complete with heat recovery was also installed, as can be seen. There are huge windows glazed with heat absorbing glass letting in even more light than before.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]2: ([/size][size=14pt]More light [/size][/font][/color]
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This is the same house from the garden which opens out even more to the sun. very few after ations were necessary to create a totally different impression of the building. The old balcony was an enormous heat bridge and was removed completely and replaced by a freestanding extension to provide extra space for sitting in the open. The solar collector on the roof is a sensible approach to sourcing energy)[/font][/color][/size]
[color=#000000][font=宋体][size=3]3: ([/size][size=14pt]A better use for gables [/size][/font][/color]
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In nearly older buildings there is almost certainly space beneath the gables which could be put to better use.
This means the house can offer more accommodation without the sloping walls do not always convey a feeling of being confined, provided that there is enough light.
But there are several important rules to follow when a roof extension is being carried out. In particular, special attention must be paid to the structure of the building, Access and roof insulation.)[/font][/color][/size]
[size=14pt][color=#000000][font=宋体]Roof conversion[/font][/color][/size]
[font=宋体][size=3][color=#000000]The easiest way to gain more space in a house without making structural alterations is to convert an attic or any other unused space in the space just below the roof structure On the face of it, this seems quite simple, and so is frequently tackled without expert advice or help. Basically, there is no reason why you should not go at it alone, provided you stick to a few basic rules. First, it is important to check that the roof structure is sound, whether there has been any water damage to the wood members, and whether there are any infestations of pests, if rafters are in need of repair, it is worth remembering from the outset that they are not likely to be deep enough for modern insulating materials. For this reason the boards for reinforcing them should be longer and wider than the rafters themselves; another approach is to enlarge the rafters with lathing.[/color][/size][/font]
[font=宋体][size=3][color=#000000]It is difficult to make a roof really watertight unless it is first completely stripped so that the battens can be removed. Undamaged roof tiles should be set aside for use on the new roof. Next, foil backed plaster board with the lowest possible resistance to vapor diffusion, or impregnated wood fiber boarding must be fixed over the rafters so that the roof will be effectively protected against driving rain and snow. It is wise to lay this sheathing between the rafters before the roof is replaced, even though it will involve far more work. Next, the tiled roof can be replaced, vented with laths on the outside, and the insulating material put into position on the inside between the rafters. [/color][/size][/font]
[font=宋体][size=3][color=#000000]It is vital to ensure that this part of the building is absolutely windproof without interfering in any way with the diffusion of water vapor. The best way of tackling this is to install a wind stop made of kraft paper or sheeting made of some kind of breathable material. It has to be laid very carefully and fixed with adhesive to the places where it joins the gable end wall, the floor and the jamb wall, as well as to all openings such as the roof windows, chimney, ventilating ducts and aerial so that the gaps are completely sealed. One has to keep in mind that the windproofing will not be very efficient if it has to be broken for wiring, heating pipes and other connections.[/color][/size][/font]
[font=宋体][size=3][color=#000000]A second conduit for these features should run between the windproofing and the inside of the out side wall: The best materials for this would be gypsum plaster board or fibrous plaster sheet or wood. This conduit can also be filled with insulating material. The advantage of this procedure is that if all the voids are filled with insulation there will be no air spaces where condensation can occur.[/color][/size][/font]
[font=宋体][size=3][color=#000000]The lighting used in the new rooms under the roof must be adequate. If roof windows are to be installed, the glass should have an area of at least 250/0 of the total of the room area subtracted from the total area of the roof on account of the sloping roof. Another method of calculating the minimum glass area is to set it at no less than one-eighth of the total area of the space.
More recently, larger roof windows have become available which can be extended to form a small roof balcony. Yet another alternative for admit ting light and ventilation is the addition of roof dormers, but the disadvantage of them is that they may need some planning or design approvals They are also more expensive, and involve more work A tradesperson will probably also be needed to carefully seal the transitions between the dormers and the roof on the outside of the building.[/color][/size][/font]
[color=#000000][font=宋体][size=3]1: ([/size][size=14pt]House on a house[/size][/font][/color]
[size=3][color=#000000][font=宋体]Arch: A. Mense. B. Burger Basra Bauburo. Dortmund Germany[/font][/color][/size]
[color=#000000][font=宋体][size=3]The height of this building has not been altered, but nevertheless an entire apartment has been constructed in the roof, with space for a small family)
2 :( [/size][size=14pt]Windproofing is very important.[/size][/font][/color]
[size=3][color=#000000][font=宋体]Arch: A Mense, B, Burger. Basta Bauburo, Donmun6! Germany[/font][/color][/size]
[font=宋体][size=3][color=#000000]This house in Bochum, Germany (opposite) shows very clearly the work involved in building a roof exten5ion; the floor will have to be re laid with special attention[/color][/size][/font]
[font=宋体][size=3][color=#000000]paid to soundproofing When larger roof windows are to be installed, framing the new openings will have to be dealt with as well Among other tasks, increased insulation wilt have to be ]aid between the rafters Most important of all is proper sealing[/color][/size][/font]
[font=宋体][size=3][color=#000000]and windproofin8, which is the function of the coated kraft paper The last step is to lay battens over the sealed in sulating layer for attachment of the interior cladding panels made of plaster board or wood.)[/color][/size][/font]
[size=14pt][color=#000000][font=宋体]Historical building materials[/font][/color][/size]
[font=宋体][size=3][color=#000000]For many centuries it was taken for granted that any new building being constructed should make use of materials salvaged from the demolition or destruction of older buildings. It was not until fairly recently that this form of recycling fell out of fashion. But there is now a gradual return to traditional ideas, prompted by both ecological and economic motives, as well as by the realization that the character of a building can be enhanced or restored to what it once was [/color][/size][/font]
[font=宋体][size=3][color=#000000]Landfills are becoming full and new locations are difficult to establish, especially near an urban area. Environmental costs of maintaining these sites is skyrocketing and therefore the costs to the consumer for refuse collection and disposal is growing at a rapid rate In the United States most construction debris must be taken to designated landfills and higher tipping fees may apply. For this reason more and more contractors are beginning to sort and recycle the debris from building and demolition projects, in addition, companies to buy and sell the recycled materials are springing up all over These companies generally restrict themselves to sorting wood, metals, plastics and minerals, which are then pulverized and treated and redirected to an end user. In some areas pulverized bricks and powdered concrete have started to replace gravel as material for road foundations. Another reason for this change is that high quality gravel has become more and more expensive.[/color][/size][/font]
[font=宋体][size=3][color=#000000]Wood doors, windows and beams are frequently ground up in a "wood hog" and turned into hardboard while metals are melted down. Doing so wastes a significant amount of the inherent value of many older building components which still have useful life left in them. Recycling structural elements such as old roof tiles, oak beams, doors, windows and flooring was for a long time something that only interested the do it yourself enthusiast. But over the last few years more and more firms have started to specialize in salvaging and reselling specific structural elements and fixtures or even in reconstructing entire buildings for reuse.[/color][/size][/font]
[font=宋体][size=3][color=#000000]Intricately carved old doors, beautifully made box bay windows with forged brass handles, antique wall tiles and glazed terracotta floors, iron shutter fastenings and delicately carved staircases, sandstone moldings and beams, are all valuable testimony to the skills of crafts men as well as of great historical and architectural value. They can all add a great deal to the appearance of almost any compatible building and are essential if a property is to be properly restored to its former glory In the United States, every community of any size has its building salvage yards and one or two architectural antique stores packed with old fireplace mantels, sandstone moldings and beams, are all valuable testimony to the skills of crafts men as well as of great historical and architectural value. They can all add a great deal to the appearance of almost any compatible building and are essential if a property is to be properly restored to its former glory In the United States, every community of any size has its building salvage yards and one or two architectural antique stores packed with old fireplace mantels, wood columns, terracotta relief panels, cornices, arch window sashes, leaded glass panels, marble wainscot, etc. which can still serve their purpose[/color][/size][/font]
[font=宋体][size=3][color=#000000]From the first guidebook on recycling of building materials, GREBE, recycling of old building parts has become a ubiquitous if not mainstream business. It is not a lucrative activity for contractors on tight commercial construction budgets or schedules, so the movement is basically fueled by the small scale entrepreneur who specializes in rehabilitating older residential and multi family buildings or the skilled do-it-youselfer working on his or her "this Old (Dream) House" renovation. On the other hand, building codes make no allowances for putting these used materials back into service nor do they exclude such practices The building must meet codes whether built of new or old materials, and one is expected to know what can or cannot "fly" with the local building inspector. A good example of a reused component which will not meet modern day codes is an older balcony railing which might typically have been constructed at a 2-3 foot height and with openings greater than the smaller than 6 inches requirement of today's codes regarding railings. If the railing happens to be a Chippendale style railing on an exterior balcony, adding the additional six inches of height will destroy the classical design quality and therefore render the railing useless for its original application. It can be used, for example, on a roof edge, where there will be no occupancy and there is no requirement for a railing but where an architecturally decorative railing will satisfy the classical design intent.[/color][/size][/font]
[color=#000000][font=宋体][size=3]1: ([/size][size=14pt]Amazing old barn door[/size][/font][/color]
[font=宋体][size=3][color=#000000]Dealers in antique fittings stock a wide range of parts from old buildings.
A new house can be fitted with a beautiful old door to give it more character)[/color][/size][/font]
[color=#000000][font=宋体][size=3]2: ([/size][size=14pt]Still useful somewhere[/size][/font][/color]
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These old windows can still be put to good use They can serve as combination windows, or as box type windows or they could be used for an unheated conservatory, shed or summer house.[/font][/color][/size]
[color=#000000][font=宋体][size=3]3: ([/size][size=14pt]The historical value of true craftsmanship[/size][/font][/color]
[font=宋体][size=3][color=#000000]Door hardware, locks and hen dies from old buildings and even the beautifully finished doors of an old country house can be used in a new building or in one being returned to its former glory Old roof flies and carefully cleaned bricks can be used to repair an existing roof or wall or to construct new ones.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]4: ([/size][size=14pt]Spacious and open[/size][/font][/color]
[size=3][color=#000000][font=宋体]Arch B. Heidbrede, Schwerte, Germany[/font][/color][/size]
[font=宋体][size=3][color=#000000]The photographs show how an attic has successfully been converted and carefully integrated into an existing dwelling The split level design enhances the alterations still further This renovation proves that improvements to an older building do not necessarily involve drastic structural changes The main beam resting on slim metal columns supports the roof, and together with the newly constructed balcony creates more space in what was a small room The large expanses of glass let generous amounts of light into the room.)[/color][/size][/font]
[color=#000000][font=宋体][size=3]5:([/size][size=14pt]A stairway can add excitement[/size][/font][/color]
[size=3][color=#000000][font=宋体]Arch:B Heidbrede, Schwerte, Germany[/font][/color][/size]
[font=宋体][size=3][color=#000000]In most cases, a new staircase will have to be part of an extension to the roof because the old steps were far too narrow and steep. This photo shows how modern materials can be used effectively to provide a solution that blends in well with the surroundings and allows more light into the new room.)[/color][/size][/font]
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