C/VM2 Fire Designs
In theory anyone considered competent, can provide a C/VM2 fire design to the B.C.A.
This is to provide a better understanding of the CPENG or Chartered professional Engineers process and the development of a C/VM2
The dbh have provided an example on their website
VM2 stands for Verification Method 2
Check out the following document that has been provided by the DBH.
I would suggest anyone with a sound knowledge of mathematics will not have a problem doing these and does suggest that fire engineering is become very technical with little requirement to consider the total fire safety package or concept.
Vincent Brannington theory
If you note the evacuation calculations it would appear. that you do your branzfire calculations with the predetermined inputs and get your aset and rset times, in this case the door width is not governed by the occupancy numbers rather the evacuation time calculated by people movement and in some cases 458 seconds to fo through one of the doors, So it would appear that there can be quite a bit of queuing as long as the times for this do not exceed the aset and rset calculations. This would appear to allow you to have narrow doors compared to the old C documents.
The saving grace in the worked example is the building has a sprinkler system and smoke detectors through the sleeping area,
IPENZ are a well established body in New Zealand and have the systems to ensure that only suitably trained people will hopefully will be doing this work.
They have decided that one of the suitable persons to do C/VM2 fire reports would be someone who is CPENG and been assessed in fire as part of there CPENG process.
It is up to the local BCA’s who they consider competent, the building code nor IANZ legislate for all this work to be done by CPENG engineers, BCA’s as long as they have a good record of why they have decided to accept reports, can accept reports from any individual.
IPENZ are promoting the CPENG.
Overview – CPEng register
Chartered Professional Engineer (CPEng) is the most important quality mark attesting to the current competence of a professional engineer in New Zealand. It is a statutory title under the Chartered Professional Engineers Act of New Zealand 2002, (CPEng Act) which established a register of professional engineers whose competence is up-to-date.
In New Zealand the title CPEng can be used only by engineers on the CPEng register administered by IPENZ as the Registration Authority under the Act. The CPEng Rules govern the way the Registration Authority carries out these functions.
Registration is gained by demonstrating competence, which is re-assessed for currency at intervals not exceeding five years. The CPEng register includes the date at which each registrant’s next competence assessment is due, and is available at all times to the public. Click here to search the CPEng register.
Chartered Professional Engineers are assessed for competence in the practice area they have chosen; practice areas are particular to each CPEng, and may include unique mixes of competencies. The Chartered Professional Engineers’ code of ethical conduct requires that CPEngs work only within their competence – they must refuse to undertake any proposed work that lies outside their area of expertise.
Some regulatory authorities specify that certain kinds of work must be carried out or supervised by Chartered Professional Engineers – for example, inspections of moving machinery through the Occupational Safety and Health Service, and certification of the integrity of structures under the Building Act.
The CPEng register lists individuals, not engineering firms. People seeking to hire an engineer usually approach a company; once the company assigns an engineer to the work, the register can be checked to ensure that the engineer is a Chartered Professional Engineer.
The principle of using CPENG recognised engineer is to ensure that it is done right the first time which was the philosophy for the change.
At this time there is limited information on record to show what each person has been assessed for and what area’s of fire engineering they are considered to be competent to do and you would have to ask the engineer before you engage and you also need to make sure that they are happy that the job is within their scope of competency.
BCA (Building Consent Authority)
It is is also going to be very difficult for the BCA’s at this time, as they will not know who is CPENG assessed for fire. Will be interesting to discuss with IANZ what responsibility the BCA has, to ensure the person providing the report is working in their area of competence, like all new legislation there will be a settling in period and I am sure some interesting debates on the way.
It is important the BCA understand there accreditation allows them to accept reports from anyone they consider competent as long as the reasons for accepting that particular persons reports are well documented.
Overview of the documentation that will be required.
Come April 2013 the existing CAS1 documents cease to exist and cannot be used.
You then have the decision to make?
C/AS 1-7 Acceptable solutions or C/VM2 Verification Method 2 ?
From reading the C/AS 1-7 it would appear they are trying to minimise the buildings that these would apply to and encourage C/VM2 fire reports as this minimises the risk to the government as once a C/VM2 this is administered by IPENZ.
There will be some cost implications for the producing of the C/VM2 fire report and would be worth getting a quote or an estimate of fees. Engineers have paperwork you will complete which outline their fees and you will sign a letter of engagement.
If the fire report is carried out using a C/M2 fire design, a fire alarm which will be either a heat detector, smoke detector or sprinkler system will be required to be installed. The installation of a fire alarm is required to use modelling to ascertain the ASET (Available Safe Exit Time) and RSET (Required Safe Exit time) times which also includes tenability limits.
This may include any alterations additions to existing buildings regardless of the extent of the work if a VM2 is used as the design document although once they realise the costs this will change and I am sure there will be some modification to the area of existing buildings. The reasonable and practicable option for the existing ,means of escape will still be much the same although will be interesting to read some of the philosophies.
In terms of cost, the fire alarm installation could be high, and what has been forgotten is the ongoing cost to maintain the systems.
Regardless of what route you take if it is a VM2 a fire alarm will be required.
HCN the forgotten most toxic gas produced in most fires. I have attached a report that has been produced following testing. There is quite a bit of reading available on the net
I also attended a seminar in 2005 and David Purser commented, ignore HCN at your peril. He commented that when modelling is used , it is important that this is used with a very good practical knowledge of fires and human behaviour.
The danger here is every one is hanging there hat on CO in terms of tenability and in particular part of the robustness test.
There is a cumulative effect also in fires so as people breath in the products as a result of whats being consumed in the fire , each will be having some affect on the person and the more toxic products the shorter the time for people to become incapacitated. HCN can knock people unconscious in concentrations of less than 50 PPM.
Branzfire is one programme that can be used as part of the modelling process. There are others that can be used. There can be a slight variation in results.