London's special beauty isn't just in its famous places; it's also in fixing up old and important houses. When we fix these old and important houses in London, it's like giving new energy to the city's history.
Technical Aspects of Refurbishment Works
Case Study Analyses
Following section contains a review of the literature.
London is the home to the world’s most historic buildings. The value of these historic buildings to London’s attractiveness, character and economy cannot be overlooked (GLA, 2011; City of Westminster, 2011; English Heritage, 2010a). Heritage tourism, considered one of the city’s only growth sectors recently, was valued at £4 billion (VisitLondon, 2011).
There is no denying the fact that icons like the Houses of Parliament contribute substantially to the overall value of the historic buildings. Still, the city is a mixture of different types of buildings, including conservation areas, new build stock, 20th-century buildings, and other undesignated pre-1900 buildings.
According to English Heritage (2011), a historic building can be defined as one that is listed in accordance with Section 1 of the Planning Act 1990 at Grades I, II* or II, OR, that is located in a conservation area designated in accordance with Sect 69 of that act, OR a building that is of historical and architectural interest referred to as a material consideration in local development framework or the local authority development plan.
English Heritage (2011c) maintains that buildings that are of exceptional interest and international importance (2.5% of the buildings) are classified as Grade I buildings. Grade II buildings are critical structures of more than special interest (5.5% of the total listed buildings). Listed buildings, however, are exempt from Building Regulations Part-L constraints despite the fact the restrictions on making changes to these buildings are relaxing to some extent (HM Govt, 2010). Applications and assessment may be required for alterations in regards to fittings for micro generation, exterior cladding or insulation and double glazing. Furthermore, some of the constraints also extend to properties in conservation areas (DCLG, 2010).
“When considering reuse or refurbishment of heritage assets, opportunities should be explored to identify potential modifications to reduce carbon emissions and secure sustainable development. In doing this, a balanced approach should be taken, weighing the extent of mitigating climate change involved against potential harm to the heritage asset or its setting.” (GLA, 2011).
However, despite acknowledging the heritage value, protecting the heritage buildings may not be unconditional. For example, the Crossrail Bill permits the government to treat the listed protection as inapplicable if it hinders work on the project. English Heritage needs to be involved, and the local authorities have the findings, but the pattern has become quite apparent in recent years (House of Lords, 2010). The level of protection is debatable, and there is a need to take a more holistic approach to determine the “importance” of heritage designation. This means that not all interior windows and walls are touched, providing a more flexible path to changing listed buildings. However, the retrofit will have to be evaluated to determine how much it affects the buildings’ facade and the uniqueness of the arrangement.
It should be noted that many listed buildings in Greater London are schools, churches and hospitals. Therefore, changing these structures may cause local social housing residents to relocate and disrupt commercial occupiers.
When it comes to executing a historic retrofit, several crucial factors come into play, including expertise, complexities, the integration of cutting-edge technologies, intricate architectural structures, and project scales. Typically, these historical structures undergo a meticulous evaluation before any retrofit project is initiated. Research conducted by Wilson and Piper (2008) on behalf of Levh Interiors, an established name in the field, has revealed that by 2050, it's projected that a significant 25 per cent of the United Kingdom's residential properties will have been constructed using traditional building techniques. The absence of modern features like damp-proof courses, sash windows, glazed bays, or solid wall constructions marks these techniques. However, a pivotal question that demands attention revolves around the extent to which these historic homes can be modified or adapted.
As much as 49 per cent of national carbon emissions are generated from the United Kingdom’s existing stock of buildings. Furthermore, it is anticipated that at least 80 per cent of these buildings will still be here even after 40 years (GLA, 2011). However, considering the current rate of retrofits, it is safe to say that most of these buildings would not be retrofitted or made free of carbon in time to satisfy the UK’s and EU’s ambitious targets for carbon emissions. A great challenge for those assigned this task is dealing with the untested and unsteady delivery, finance and policy mechanisms. The challenges for the Greater London region are even more complicated as much of the building stock dates back to the Victorian era (Cassar, 2009). This includes more than 1,000 conservation sites (including over 570,000 homes), hundreds of thousands of buildings which are protected to some extent, and as many as 20,000 listed buildings. Managers, residents, and owners must take special care when working with designated buildings to protect London’s uniqueness and comply with regulations.
In accordance with section 66 of the Planning Act 1990 that deals with Listed Buildings, the City Council must decide whether permission for development or alteration affecting listed buildings or their façade should be granted. City councils must pay special regard to preserving the attractiveness, setting and any other features of significant historic or architectural interest. The government suggests always favouring the preservation of listed buildings, but each case should be evaluated based on the facts and results anticipated from demolition or alteration. The Secretary of State for Sport, Media and Culture is solely responsible for listing the buildings (DCLG, 2010).
As previously indicated, all those buildings with significant historical and architectural value can be classified as listed buildings. The list descriptions do not provide a complete record for all aspects of interest and are mainly used for identification purposes only (DCLG, 2006). Therefore, these descriptions should be noted and relied upon regarding the consent for works to a particular structure. Some buildings situated in the curtilage of a listed building are also subject to building control despite the fact they are not indicated in the account (English Heritage, 2011b).
Alteration, extension and demolition works can affect the character of a listed building as a structure of special historical and architectural interest. Therefore, a listed building consent is required for a listed building before such works may begin. Some alterations, such as changes to the interior, routine repairs, maintenance and renewal of concealed services, do not require approval. However, more impelling repairs may require approval depending on the character and their degree (Hansard, 2011).
Many old houses were constructed on shallow foundations with load-bearing walls. The ground floor was constructed using wooden boards or solid construction, while the upper floors were made from suspended timber.
Solid brickwork of varying widths was used to make the walls, the design of which differed according to the style of the house and the construction system employed (Green Deal Guide, 2011). Various types of covering materials and wooden rafters were used to construct the roofs of such houses. The drainage systems consisted of downpipes and cast iron gutters. A special type of window known as the “double hung sash window” was used, and the dwellings consisted of gas stoves and fireplaces for heating purposes (Cesar, 2009).
Any particular refurbishment repair and alteration in the listed building requires the specialized expertise of the contractor to complete the refurbishment works successfully. The refurbishment works can include various tasks/activities, materials and alterations with respect to the structure involved. Hence, a single form of guidance cannot be applied to these works.
The scope of works to be undertaken is analyzed through a detailed inspection of the house/structure involved. Various key parameters such as demolition works, kitchen, AC units, under-floor heating, general building works, electrical, plumbing, cornices, plastering, tiling, carpeting and various other works are categorized and sub-categorized to form a detailed list of Bills of Quantities by the requirements of the clients. The proposal in terms of an outline and scope of works is then filed to attain necessary approvals from the local city council to start the refurbishment. A contract is normally signed against the scope of work (between the client and the constructor) to avoid any misunderstandings/disputes concerning the works undertaken by the contractor.
The following are the key aspects that are considered to be of prime importance when dealing with the refurbishment of old dwellings:
Roof type, material and structures of any historic building are of significant interest concerning the retention of the overall structure. The original roofs, “m” shaped or “double-pitched”, must be preserved through proper concealing and strength optimization. The late eighteenth-century roofs made from clay tiles (clad from), natural Welsh slate, copper and lead can be preserved through Portland cement/stone coping in the foreground and a re-installed rainwater piping system. Replacement of these original historic roofs is not acceptable under most circumstances. Furthermore, the decorative features of the tops must also be repaired, such as a decorative ridge, cresting and finals (SDC, 2006).
Any plan of roof extensions will have to be in accordance with the relevant policies (such as DES 8F) and require approval from the council office. Any repair to flat roofs, gutters and weathering must be by the standardized practices; for example, if any lead works are completed, it must specify the sheet sizes, thickness, jointing, etc., so the optimum durability standard of architecture involved is maintained. Similarly, the chimney, part of the roofscape and original structure, must be carefully retained and repaired if needed.
The facing materials of the building in the original form must be retained/exposed to ensure that the structure’s constructional background is not compromised. Therefore, rendering the bricks, re-cladding and painting exterior brickworks, composite or other stones, must be avoided. Specialized expertise must be implied to repair the bricks/stones/terracotta, and it must be ensured that the works completed match the original forms of the colour, bond, dimensions/pointing and texture, etc. (Cassar, 2009). For example, the front elevation constructed through white brick and limestone (normally in churches in London) can be refurbished by piecing matching stone in the areas which have been heavily eroded.
Issues: In the higher humidity localities of London (close to the river), there is always a considerably higher risk of decay in traditional masonry of old structures. It is important to note that using hard-based cement mortars for re-pointing can potentially cause damage to such exterior surfaces. This is because of reduced porosity in such renders and mortars compared to lime-based mortars, allowing increased moisture to be trapped in the outer wall, accelerating the decaying process. Therefore, refurbishment of the external wall in such localities must be addressed through an engineered selection of aggregate to achieve suitable repairs and finishing.
The interior designs, furnishings and partitions are all important aspects that must be carefully examined when considering the refurbishment works of historic homes/buildings. Windows and doors must be retained to be successfully repaired and replaced where there is an absolute necessity. However, the replacement of any interior materials must be carefully selected, ensuring that the replacement matches the original design, dimensions, finishing, etc., as much as possible (SDC, 2006). It must be assured that the historic fabrics of the significant elements are not influenced, especially in sensitive locations.
The structure's floor plan, which includes the room proportions and partitions, showcases evidence of the fundamental characteristics of the old buildings. Therefore, any changes in the plan, such as suspended ceilings, fire lobby or raised floor, must not be incorporated into the plan if it is going against the historic or architectural interest. It is also important to note that in the modern extensions of the listed buildings, fundamental changes in partitions may not necessarily impact the historic or architectural character of the building; however, these changes must be presented on a scaled drawing, and information must be sought from the City Council’s office; to find out whether any form of consent is required before undertaking the refurbishments works. The structure of the old house buildings can greatly benefit from appropriate internal decorative finishing, such as elaborative plastic works and flooring.
Another important aspect, which is often considered for refurbishing old houses, is installing internal services. Since most such buildings do not incorporate internal concealed services, these are mostly installed during the refurbishment of the dwelling. These services include installing air conditioning systems, ducting, ventilation systems, security systems, kitchen up-gradation, radiators and installing state-of-the-art electrical and plumbing services (Retrofit for the Future, 2011).
Issues: Installation and provision of such systems/services may depend upon the locality and the type of the subject dwelling. For example, in central London, conditioning (AC) services are considered a fundamental requirement, as the summer temperatures can reach a highly uncomfortable zone. The installation of the AC system and the connected extract ducting must be carefully designed to reduce the impact of the installation works on the appearance/fabric of the traditional interiors. In many cases, this may be achieved through providing unconventional engineering services to the client. Therefore, this service requires integrating the service equipment (internal/external cooling units, ducts, pipe works, etc.) with the design of the building.
Another crucial technical issue faced during the refurbishment of old housing/dwellings is the access to and within the old buildings. The accessibility concerns, especially for people with disabilities, must be carefully examined when undertaking refurbishment works. Many ancient dwellings in central London's locality have limited accessibility through the steps/ stairs across the basement or entrance areas. Sufficient access points while maintaining acceptable entrance widths must be provided to ensure practical access. These issues can be resolved by extending the entrance/lobby areas, effectively positioning handrails, providing wheelchair access, etc., depending on the specific circumstances.
Major alterations involve much of the demolition work and may require the City Council's prior approval. Since the aim is to preserve the historical structures, any minor defects in the structure could not justify the undertaking of major reconstruction works.
Therefore, it is important to investigate the existing structural works and identify the reasons/justifications for carrying out major refurbishment works (SDC, 2006). For instance, if the analyses show a risk of structural collapse (partial or total), a formal method statement of reconstruction can be produced and shared with the council’s office, highlighting the scope of works, reasoning, and techniques for refurbishment. The proposal may include re-building, underpinning, floor strengthening, structural member replacements, etc. The report of the detailed assessment is to be produced by the experienced contractor/engineer, which can include information such as crack patterns through annotated sketches/drawings, plumb and level surveys, and the structure’s background information such as the age of the structure and recent maintenance history, etc.
A case study analysis has been completed in the following to comprehend the requirements of the refurbishments works in old/historical houses.
As a part of the group “Naser Property Management Services” (a family construction business), information was obtained for various works completed during the refurbishment of old houses. The information obtained from the company includes the scope of work and the detailed bills of quantities, which were agreed upon between the client and the service provider.
The traditional practice is that client approaches the company with the request to complete various refurbishments works. The construction company first investigates the requirements and produces survey results. Based on the results, formal works plans are established, and bills of quantities are shared with the client. After obtaining approval from the client and local council, the works were initiated (refer to Appendix 1 for details).
The same practice was followed for refurbishing an old house: “4 Belgrave Square, London SW1X 8PH”, details of which have been presented in Appendix 1.
Reviewing the scope of works in this project, it was observed that much of the demolition works were undertaken, including removing equipment/appliances, furniture, walls and tiles, partitions and services equipment. This was completed to install various new equipments such as kitchen utilities, AC units, underfloor heating and other services for the client. The details of the works, along with the costs involved, are summarized in the following;
The expenses incurred during the refurbishment works amounted to £94,915, including the labor and installation costs.
Reviewing the details of the different bills of quantities obtained from the “Naser Property Management Services” company, a similar pattern of refurbishments requirements were observed for various cases/clients. Furthermore, during the literature review, similar specialized requirements were observed, strengthening the argument that the refurbishment of old houses requires “facility development” to incorporate the new needs of the modern residents. These include modern facility services, accessibility, controlled environmental conditions, emergency efficiency, electricity, durability along with various other requirements.