Fire engineering

In most situations compliance with approved Document B, (Fire Safety) or BS 9999:2008, (Fire safety in the design, management and use of buildings) or, BS 5588-1, (Fire precautions in the design, construction and use of buildings for residential buildings) is appropriate for the design of fire safety in most classes of buildings. In large or complex buildings, often with mixed use, BS 7974 0-7 (Application of fire safety engineering principles to the design of buildings) can often be the only solution.

It is a general rule that In terms of fire safety the design of all buildings should be as simple as possible. This is because complex systems can be difficult to understand and usually require a high level of management and competence. Where possible a simple and general approach should be adopted. In the majority of projects in the UK designers follow simple guidelines such as Approved Document B to demonstrate compliance with the Building Regulations.

BS 9999 is used where a more advanced approach is sought. It is closely linked to fire safety management and is a risk based design solution. Many of the fire engineering principles embedded in BS 7974 are used but it does not provide a fire engineering solution. It is a much more structured approach that allows the designer more flexibility through greater understanding of the human and physical factors that affect risk.

Fire engineering provides an alternative approach to fire safety. Fire engineering solutions can overcome the prescriptive requirements of the general and advanced approach and enable the erection of large complex structures such as stadiums or atrium buildings. Fire engineering enables a comparative study of various safety levels for alternative design solutions and identifies areas for research to enable cost effective design solutions. Fire engineering by its very nature enables the development of fire safety not only at the design stage but also during the life of the building.

Fire engineering is often the preferred approach when design solutions are required for the alteration or change of use of historic buildings. In these situations the conservation of the fabric and character of the building becomes paramount.

Disproportionate collapse – what does it mean?

Ronan Point was a 22 storey block of flats in Newham London. In 1968 it suffered a partial collapse due to a gas explosion in a kitchen on the 18th floor . The tower block was built using a technique called ‘Large Panel System Building’ or ‘Large Panel Construction’. The system consisted of bolting together floor and wall panels in a systematic way. The system relied on the bolted connection to maintain structural integrity. The effect of the gas explosion was to cause a ‘progressive collapse’ of the whole south east corner of the building. (See inset picture) To overcome the problem buildings are constructed so that the failure of a beam, column or wall does not cause a ‘disproportionate’ failure of other elements in the building.

Requirement A3 states that ‘A building shall be constructed so that in the event of an accident the building will not suffer collapse to an extent disproportionate to the cause’. The requirement does not apply to all buildings. It usually applies to large and/or tall buildings including dwellings. In order to understand the guidance it is usual to classify the buildings. Class 1 buildings are generally small buildings that do not require any special robust detailing. Class 2A buildings such as five storey dwellings or offices not exceeding four storeys attain robustness by the provision of horizontal ties. Class 2B buildings such as hospitals not exceeding three storeys attain their robustness through horizontal and vertical ties. Class 3 buildings are buildings that that are defined above Class 1, 2a or 2B and are generally large or tall buildings, grand stands or buildings containing hazardous materials. In these buildings the construction requires a systematic structural risk assessment. The risk assessment takes into account all normal and abnormal hazards ranging from failure due to accidental impact to explosion. The relevant structural codes and standards provide further guidance.
The requirements can often impact on change of use, refurbishment work where structural alterations take place or where a building is extended especially by the addition of a floor.

Part G - water efficiency calculator

There is a requirement in Regulation G2 that fittings such as taps and fixed appliances, such as washing machines installed in new dwellings will be water efficient to prevent undue consumption of water. The potential consumption of wholesome water by persons occupying a dwelling must not exceed 125 litres per day. This applies to newly erected dwellings or new dwellings brought about by a change of use such as conversion of a house into dwellings. The regulations require the person carrying out the work to notify the building control body of the calculated potential consumption. The estimated water consumption of a new dwelling should be calculated in accordance with the methodology set out in the ‘Water Efficiency Calculator for New Dwellings’. This is published by CLG Publication and is available on line at the following address. http://www.communities.gov.uk/publications/planningandbuilding/watercalculator
There is software available which can be used to assist you in the calculation. Some sites such as WRc PLC provide free on line software that can be used to carry out the calculation for you. Other sites provide software that you can pay to download. The link to WRc is provided below.
http://partgworkshops.wrcplc.co.uk/water-efficiency-calculator.html

Why a Building Survey is so essential

Homebuyers are facing bills for thousands of pounds by failing to have an appropriate survey of their property according to the Royal Institute of Chartered Surveyors.
25% of homebuyers rely solely on a valuation survey and not on an in-depth building survey as recommended by the RICS. This resulted in unplanned expenditure that amounted to an average expenditure of approximately £1800 although; the figure could be much more.
Building surveys enable prospective purchasers to make informed decisions when purchasing a dwelling and if carried out at an appropriate time can save a great deal of money in legal fees.
It is wrongly assumed by many purchasers that a mortgage valuation report is a building survey report. This could not be further from the truth. It is solely an indication of a property’s value for loan purposes only. It is prepared by the lender and not the purchaser. The significant matter is that it will not uncover any potential problems.
Research carried out by the RICS indicates that 58 per cent of respondents wrongly believed a valuation report included the building’s condition, including searching for damp and structural movement. A further 31 per cent mistakenly believed that it contained legal advice that falls within the domain of a solicitor.
The RICS recommend that you appoint your own surveyor to carry out a building survey even if you are paying for a valuation survey for the lender. A building survey is of particular use if the building is historic, in a bad state of repair or where there have been major alterations or a change of use. It is recommended that you provide a brief to your surveyor outlining your own concerns and include any proposals for future alterations or extensions.
A survey will help you to appreciate the value of the property and enable you to prepare costs for future maintenance and repair. The surveyor will alert you to significant costs and you will be able to use this information to renegotiate the final price of the property.
if you want further information on the type of surveys available or need to talk to a surveyor then contact Oculus. You can also visit the RICS website at the following address. http://www.rics.org/