• the rational design;
• the deem-to-satisfy-rule; and
• the agreement certificate.
The deem-to-satisfy rule of design
was intended for a building where an
engineer is not required due to it not
being complex in terms of size or height,
for example. The deem-to-satisfy rule of
design is basically a ‘one-size-fits-all’,
whereas the rational design is an ‘exact
fit’ or ‘fit-for-purpose’, which could mean
more or in some cases or sometimes
less than the deem-to-satisfy-rule.
These are the original definitions of
the deem-to-satisfy rule and rational
design, but somewhere, somehow,
rational design came to mean ‘or equal’.
If it must only be equal then the rational
is not relevant anymore, they cancel one
another out – and this doesn’t make sense.
The fire water system
The design of the fire water system
in terms of the NBR is SANS10400-W
(also referred to in SANS10400-T
and SANS10252-1), is a design code
of practice which was changed to a
Standard under the Water Act and
contains a section for fire water.
It is important to note that
SANS10252-1 was promulgated under
the Water Act and not under the NBR
Act and is therefore not the mandate
of the Building Control Officer, however
there is reference to this document as
The fire water section of this
document refers to a situation where a
building is of such height ‘where the fire
department cannot reach’ and that the
of this property and therefore, the
requirements for infrastructure design
cannot be considered compulsory within
the jurisdiction of the NBR. The design
standards for water infrastructure end at
the boundary of the property and cannot
be applied within the property boundary.
To ensure that no confusion sets in,
it is very important to understand the
institutional framework of the NBR.
The NBR is based on the NBR Act of
1977. It consists of regulations, which
are compulsory and are contained
in Annexures, and it describes the
performance of systems.
Then there are a number of ‘deem-
to-satisfy-rules’, which are basically
a ‘recipe’ of how to comply with the
regulations. These are, however, not
compulsory, and the owner can choose
to apply them.
There are three methods of design and
construction to follow in order to comply
with the regulations namely:
Fire departments have insisted that the owners of properties must provide large volumes
of water on their properties, specifically reserved for firefighting.
owner must provide pumps to reach the
height of the building. The focus element
here is the pumps.
However, large pumps that must pump
from ground level directly out of a water
supply pipe to the top of a high-rise
building are not acceptable, and not
allowed by local authorities. Therefore, a
break pressure tank is required for this
purpose. It was agreed, in conjunction
with the fire authorities, to provide a
quantity of water in tanks for the pumps
– the size of which is determined by fire
officers to be 25 000ℓ.
It is not intended that the size of this
tank hold the total quantity of water
to fight a fire, but rather that the tank
is filled constantly from municipal fire
hydrants via a fire hydrant with a dry
pipe to the tank while the pumps are
You cannot separate the fire water
system of a building from the municipal
water infrastructure, yet this ‘stipulation’
falls under two different acts, two
different authorities and two different
Some fire officers refer to SANS 10090
to enforce their requirement of large
fire water storage tanks and pumps
and it seems they prefer water as the
only medium for fighting a fire.
The building fire water system
under the NBR and building standards,
depends on the municipal bulk water
infrastructure supply and fire hydrants
to ‘fight a fire inside a building’.
There is a dire need for all role
players and stakeholders to come
together and find consensus on
the issues and problems and find
solutions to satisfy everybody in the
supply of water and the use of water
for fire protection.
The important role players /
• Municipal water engineers
• Municipal fire officers
• Municipal town development
• Building control officers
• The NRCS
Local by-laws • The SABS
The local by-laws also refer to
The problem is that the local authorities
clearly state in their by-laws, in terms of
the Water Act, that their water is provided
under three conditions, as follows: • SAICE
• The Architect Association
• Insurance companies
• NO guarantee of water.
• NO guarantee of pressure.
• NO guarantee of quality.
These three elements must be secured
by the owner at his own cost, if they wish
to do so.
Water Sewage & Effluent May/June 2019
It is important that these solutions be
applicable nationally and take into
consideration solutions where water
supply is a problem and how to find and
apply alternative solutions.