Technical Aspects of Refurbishment Works

A large number of old houses were constructed on shallow foundations having 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 sued 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 as well wooden rafters were used to construct the roofs of such houses. The drainage systems consisted of down pipes and cast iron gutters. A special type of window known as the “double hung sash window” was used in and the dwellings consisted of both gas stoves and fireplaces for heating purposes (Cesar, 2009).

Any particular refurbishments repair and/or alteration in the listed building requires specialized expertise of the contractor to be able to successfully complete the refurbishment works. The refurbishments works can include a variety of tasks / activities, materials and alterations with respect to the situation of structure involved, hence a single form of guidance cannot be applied for these works.

The scope of works to be undertaken is analyzed through 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 in accordance with the requirements of the clients. The proposal in terms of an outline and scope of woks are then filed to attain necessary approvals from local city council, to be able to start the refurbishment. A contract is normally signed against the scope works (between the client and the constructor), to avoid any form of misunderstandings / disputes with respect to the works to be undertaken by the contractor.

The following are the key aspects that are considered to be of prime importance when dealing with refurbishment of old dwellings:

Roofs

Roof type, material and its structures of any historical building is of great interests with respect to 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 re-installed rain water piping system. Replacement of these historic original roofs is not acceptable under most circumstances. Furthermore, and form decorative features of the roofs must also be repaired, such as 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 would require approval from the council office. Any form of repairing to flat roofs, gutters and weathering must be in accordance with the standardized rule of practices; such as if any lead-works are completed, it must specify the sheet sizes, thickness, jointing etc.; so that optimum durability standard of architecture involved are maintained. Similarly, the chimney which is the part of the roofscape and original structure must also be carefully retained and repaired if needed. 

Exterior

The facing materials of the building in original form must be retained / exposed as it ensures that the structure’s constructional background is not compromised. Therefore, rendering of the bricks, re-cladding and painting of exterior brickworks, composite or other stones etc must be avoided. Specialized expertise must be implied to repair the bricks/stones/terracotta, and it must be ensured that the works completed matches the original forms of the color, bond, dimensions/pointing and texture etc (Cassar, 2009). For example, the front elevation constructed through white brick and limestone (normally in churches of London) can be refurbished through 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 the use of hard based cement mortars for re-pointing can potentially cause damage to such exterior surfaces. This is because reduced level of porosity in such renders and mortars as compared to lime based mortars, which allows increased trapping of moisture in the exterior wall, hence accelerating the decaying process. Therefore, refurbishment of external wall in such localities must be addressed through an engineered selection of aggregate to achieve suitable repairs and finishing.

Interior

The interior designs, furnishings and partitions are all important aspects which must be carefully examined when taking up the refurbishment works of historical homes / buildings.  Windows and doors must be retained where they can be successfully repaired, and replaced where there an absolute necessity.  However, 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 ensured that the historic fabrics of the significant elements are not influenced, especially in the sensitive locations.

The floor plan of the structure that 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 in the plan if it is evidently 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 clearly 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 more often considered for refurbishment of old houses, is the installation of internal services. Since most of such buildings do not incorporate internal concealed service, these are mostly installed during the refurbishment of the dwelling.  These services include installation of air conditioning systems, ducting, ventilation system, security system, kitchen up-gradation, radiators and instillation of 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 as well as on the type of the subject dwelling. For example, in the central London, the air conditioning (AC) services are considered to be a fundamental requirement, as the temperatures in summer can reach in a highly uncomfortable zone. The installation of AC system and the connected extract ducting must be carefully designed to reduce the impact if 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 integration of the service equipment (internal / external cooling units, ducts, pipe-works etc) with the design of the building.

Another important technical issue faced during refurbishment of old housing / dwelling is the access to and with-in the old buildings. The accessibility concerns, especially for people with disabilities must be carefully examined when undertaking refurbishment works. Many of the old dwellings in locality of central London have limited accessibility, through the steps/ stairs across the basement or entrance areas. Sufficient access points while maintaining sufficient entrance widths must be provided to ensure practical access level. These issues can be resolved through extending the entrance/lobby areas, effective positioning of handrails and providing a wheel chair access etc., depending on the specific circumstances.

Major Structural Alterations

Major alterations involve much of the demolitions works and may require prior approval from the City Council. Since the aim is to preserve the historical structures, any minor defects in the structure would not be able to justify undertaking of major reconstruction works.  Therefore it important to investigate the existing structural works and indentify the reasons/justifications to carry out major refurbishment works (SDC, 2006). For instances, if the analyses shows that there is a risk of structural collapse (partial or total), a formal method statement of re-construction can be produced and shared with the council’s office, highlighting the scope of works, reasoning and techniques to be used for the refurbishment.  The proposal may include re-building, underpinning, strengthening of floors, structural member replacements etc. The report of detailed assessment 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 structure’s background information such as age of the structure and recent maintenance history etc.

Case Study Analyses:

A case study analyses 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 works and the detailed bills of quantities, which was agreed 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 produce survey results. Based on the results, formal plans of works are established and bills of quantities are shared with 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 the refurbishment of an old house: “4 Belgrave Square, London SW1X 8PH”, details of which have been presented in the in Appendix 1.

Reviewing this scope of works in this project, it was observed that much of the demolition works were undertaken which included the removal of equipment / appliances, furniture, walls and tiles, partitions and services equipments. This was completed to install various new equipments such as kitchen utilities, AC units, under floor heating and various other services for the client. The details of the works along with the costs involved are summarized in the following;

• All the demolition works (which include demolition of various walls) and disposal works were completed for a total of £4,500
• A new staircase handrail was also installed in the facility to optimize the accessibility of the house, for a total of £1,500.
• Underfloor heating works were completed for £2,900, where as a new kitchen was fitted for £4,500.
• A new air conditioning system was also installed for total of £14,000
• The general building works included the works such as new partition walls, doors, maintenance of windows, ceiling works, ducting and gypsum boards installations. Furthermore, much of the electrical works were re-installed to facilitate the requirements of the client, for a total of £15,400.
• The plastering, supply of cornices, plumbing and bathroom works, tilling, carpeting, wall, ceiling and woodwork decorating works were completed for a total of £53,715.

The expenses incurred during the refurbishments works accumulated to a total of £94,915, including the labour 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 requirements of the modern residents. These include modern facility services, accessibility, controlled environmental conditions, emergency efficiency, electricity, durability along with various other requirements.