Rehabilitation &

historic preservation

Negar Asoobar

The rehabilitation of historic buildings involves two processes which should Be complementary.Rehabilitation seeks to extend the useful life of an existing building. by introducing such changes as may be necessary.The purpose of historic building legislation is to protect & preserve a building’s historic character.The retention of historic character makes rehabilitation more difficult or more expensive and historic building legislation needs to recognize the inevitability of such conflicts.To be effective in achieving its aims, historic building legislation must give to those charged with its administration adequate powers and funds and a clear guidance on how to apply general policies in particular situations.

What from of legislation is likely to be most effective?Conservation is about the values which have been given to existing buildings. People frequently have differing values, so the conservation of historic artifacts inevitably involves a political process which has to resolve or choose between competing values. National values may differ from local or regional values which again may differ from those of individuals concerned. Conservation has financial implications for the community as well as for the owners of an individual building.The rehabilitation of a disused warehouse for commercial use will bring tax revenue into a city which it would not otherwise have enjoyed. In contrast Preventing the demolition of an historic building and so preventing redevelopment of the site will deny, not only the owner of potential site betterment, but also deny the local authority potential tax revenue.Approaches differ from country to country with wide differences being found in the balance between powers available and the clarity of the policies being. A useful comparison to explore is the difference between American and British legislation because it facilitates a consideration of the range and type of conflicts possible between rehabilitation and historic interests and suggests ways in which policies in Britain may need some clarification.

Elements of comparison:

TERMINOLOGYFirst, there is a clear difference in terminology between America and Britain Britain they says keep things as they are

Britain, says; conservation involves of some remedial maintenance this process may involve the replacement of some existing materials that’s involve bringing a building up to existing standards of comfort and safety by introducing modern services and equipment.These difficulties can be avoided by admitting that in Britain we are in fact trying to preserve something; we are trying to preserve part of the historic character of our cities, towns and buildings.In United State historic preservation it’s clearer and more specific.The historic preservation in America its meaning clearer than conservation as used in Britain.

HISTORIC CHARACTERHistoric character must reside in the recognizable attributes of the building. The materials of its construction, its overall proportions, and its fenestration, in the use of particular colors, in its windows and doors, and it will differ for each building.Essential part of the historic character may be the surroundings of the building. The historical significance of a building may reside in the activities which it supports and that a market, a railway station or a church cease to retain their character when converted to convention centers, museums or restaurants. The significance of some buildings lies in their historical association, their association with some person or event or in the institutions which they house. Other buildings are valued simply for what may be described as their architectural qualities.Historic preservation is the act, or perhaps the process, of preserving these character-defining features even though other features of the building may be changed. It is also worth nothing that there are different reasons for valuing historic character which may affect our approach to its preservation.

Historic preservation in the United States

The overall pattern of legislation in the US is more complex because national laws are modified by state and local control.National legislation for historic preservation is confined to providing incentives, in the form of tax credits, to encourage rehabilitating historic buildings to acceptable standards. This means that the standards to which owners must conform if they wish to benefit from these tax credits have had to be defined and published.

AMRCIAN STANDARDSThe secretary of the interiors standards are deceptively simple and are set out in table, they are supplemented by Guidelines which amplify the provisions and indicate the way in which they should be applied in particular cases. Applications for tax credits are made on a standard form on which the applicant describes the features of the building which define its historic character, together with drawing or photographs which show these features. The applicant indicates the work to be carried out so that the reviewing officers can assess the effect.Application to the regional office of the National Park Service (NPS),The Central office in Washington DC.In practice application are often referred back to the designers at earlier stages for modification to ensure conformity with the standards. Important differences between US and Britain practice should be noted. because permission is not required for alterations to historic buildings, it is possible for applications for tax credits to be made at may stage, even after work has been completed.

Clearly it is more sensible for developers to apply early to ensure that their proposed changes meet the standards, but this is not always done. Although the use of regional offices to administer the programmed and apply the standards may suggest a possible diversity in their interpretation.The study has concentrated on the state of Washington, which is in the NPS Western Region and which has its head office in San Francisco.NPS NPS BULLETINSBULLETINSThe bulletins issued by the NPS suggest that the reason for the

failure of applicants for tax credits to meet the standards may be divided into different categories. First, there are changes made to the building which are essential to the rehabilitation. Unavoidable changes in historic character. Secondly there are actions which are the result of ignorance or misunderstanding, actions which presumably would have been avoided had the architect been better informed. Finally, there are changes to the building which represent a willful conflict between the intentions of the design and those of the standard.

Features of the design which were not fundamental to the scheme and which might have been handled differently by different designers.

The category, depends the intentions of the architect or the owner of the building.

The appropriateness of a scheme should be the first consideration in any rehabilitation design, the designer considering if the proposed change of use is compatible with the historic character of the building.Where changes are the result of such actions as aggressive cleaning, inappropriate replacement cladding materials. Insensitive enclosures of porches or choice of replacement windows, loss of historic character could have been avoided by better informed design and specification.

Conflicts Between Conflicts Between Rehabilitation Rehabilitation

& & Historic Preservation Historic Preservation Roof – top additions presented a problem. Those additions did not

seriously affect the massing or scale of the existing buildings.An increasing popularity of roof-top additions was reported by one respondent as a result of increasing awareness of the tax benefits to be gained. Existing owner occupiers might use the credits to rehabilitate their building.Recently there had been an increasing trend towards the acquisition of historic buildings by companies looking strictly for the financial gains which depends upon their historic status.Windows also present a serious problem, its recognized by the NPS National Office which has issued a number of bulletins illustrating unsympathetic designer for replacement windows and has also organized a major conference on this subject.

The causes for complaint noted by the state reviewing officer die not concern the design of replacement windows. The standards indicate that repair is preferable replacement, but that any replacement windows are in the same material as the originals. The standard presents problems when a proportion of windows are beyond repair.It should also be noted that substitute materials are sometimes availableWhich give the same appearance and are preferred to the originals by developers because they offer better maintenance or thermal performance and in some cases these have been approved.

Interiors were mentioned in two contexts. First, that of ensuring that their value is realized. The assumption may be made that interiors have no historic value, possibly leading to their destruction.The second is the problem of plaster to expose brickwork. This is largely a matter of education; there has been something of a vogue for exposed interior brickwork. A difficulty here is that the intention to carry out this treatment may not be apparent in the original application documents and may only be discovered at final certification stage.

Store fronts also present one of a number of problems of conflict with building codes. For examples; flush store fronts with doors opening on to the street present a conflict between the requirement for an outward opening door and for the door not to open on to the sidewalk and so present a hazard. A recessed doorway would involve a change of character- a particular loss in view of the poor survival rate of store fronts.

The requirement for ties in masonry construction for earthquake resistance in Seattle is that these should terminate in rosettes on the external wall.This is done an existing building it naturally affects the external appearance. This was once accepted by the NPS, but it is now objected to.Is possible in some walls without rosettes but it is a difficult technical problem and not possible in very thin walls.

Were mentioned as a particular example and it was suggested that the form in which applications are submitted to NPS may not be sufficient to show the context and thus the impact of a particular addition whose impact may be exaggerated by elevations.

Criticism Of NPS Criticism Of NPS StandardsStandards

The criticism of the NPS standards and their interpretation:

-Toward additions which may fail to recognize local context.

-Toward retention of historic fabric when replacement would be acceptable.

-To over-scrupulous avoidance of fake historic. This needs a little enlargement because it seems to cause the most concern.

-The attitude to the completion of historic designs. Where the original buildings was not built to the complete design. Upper floors were left off perhaps. Today with money for additions, it is argued by some that it is appropriate to complete the building to the original design.

If there is a perceived inconsistency, this may be If there is a perceived inconsistency, this may be because the interpretation of the standards differs because the interpretation of the standards differs between different reviewing officers or because between different reviewing officers or because there have been changes in interpretation with there have been changes in interpretation with time.time.The programmer has naturally evolved with time The programmer has naturally evolved with time and, because of this, changes are to be expected. and, because of this, changes are to be expected. It was also pointed out that there has been an It was also pointed out that there has been an increasing interest in and importance placed upon increasing interest in and importance placed upon vernacular buildings over the past ten years.vernacular buildings over the past ten years.