Basic guidelines to owner home
building (South Africa)
Many South Africans are choosing to build
their own homes instead of buying an existing property.
Reasons for this vary but mostly for the cost saving (It is
said that a saving of 25% can be made on the capital outlay
of the proposed project when building yourself as oppose to
buying), other reasons might include the great challenge of
taking on a building project or the fact that it can create
a great sense of self-achievement.
For a number of reasons the cost of building
went up tremendously in the last couple of years. In 1998 an
average house with regular finishes could be build for appx.
R1800/sqm whereas at the time of writing this document
(2006) the rate of building the same house would be around
(R3500/sqm) This probably had a huge influence on the
‘property boom’ as perceived by South Africans in the recent
With the above in mind, it goes without
saying that it is essential to hire a good contractor (for a
list of good contractors in your area, contact the NHBRC –
National home builders registration council) Also know that
getting a building loan from a respectable financial
institution would require you to hire a contractor who is
registered with the NHBRC, a loan would not be granted
The experience, skill, efficiency, and
contacts of a seasoned professional contractor can yield
dividends for years.
A SUITABLE STAND
Try to avoid irregular shaped plots, if
possible a square or rectangular shaped plot lends itself to
easier planning. Optimum shape are more or less a 4:3 ratio.
If considering a pan-handle, know that the pan-handle makes
up a lot of the size of the total area of the plot and that
this is generally un-usable and would cost generally more to
pave that a regular plot.
Generally flat sites are easiest to build on,
but one might choose a sloped site as it often is
accompanied by great views, but keep in mind that sloping
sites, no matter how steep will often call for professional
help in the planning stages.
If you are planning to possibly extend the
house in future make sure the site lends itself towards
making this possible sensibly. It would often not make sense
to extend if there is only open space on the western or cold
southern side of the plot.
North facing plots are the best in the
Southern hemisphere as they get more sun, especially in the
winter months when the sun is lower. Views or other
advantages will influence a buyer to buy alternatively
orientated sites, but never consider buying a western
orientated site – you will seriously regret it afterwards.
Do a proper soil investigation before buying,
or ask the developer/seller to provide you with a soil test.
The cost of building on un-suitable soil is surprisingly
higher with the need for special excavations & foundations.
Access to site
Mull over the possible accesses to the site,
this often becomes a huge headache during building and even
more so in many cases once you have moved in.
BUILDING THE SUPERSTRUCTURE
Make sure your builder has a proper store for
the building materials delivered to site to prevent theft
and also to protect the materials from weather, especially
cement should be kept free from all moist at all cost. Bags
of cement could be stored on a platform lifted on bricks
Don’t construct the storage hut too far from
the road for easy delivery. Make sure that the proper
sanitation facilities are provided as well and make
arrangements to have the water connection activated.
This process involves the marking out of the
building with lime powder, corner pegs and datum level
references. Once the marking out is complete, make sure to
double check that the proposed building does not cross
building lines or servitudes.
If you are building on a sloped site the cut
& fill excavations & filling will have to be done before
Excavations & Foundations
Make sure that the excavations for the
foundations are level and at least 550mm deep, most local
authorities require the top of the foundation to de at least
340mm (4 brick courses) deep and see that the excavated
trenches are free of water before concrete casting
commences. For external walls the foundations are to be a
minimum of 550mm wide for cement bricks and 600mm for clay
bricks for a one storey building. The foundation depth to be
around 230mm min. deep. These are for normal soil
conditions. If you suspect that you have special conditions
ex. Silt, Clay etc. consult your engineer as you may require
a special raft foundation or even piles in cases where the
top layer of extreme unusable quality.
When building on a sloping site, a stepped
foundation may be required. Make sure that the top
foundations ends overlap sufficiently (appx. 250mm) over the
bottom strip for a normal strip foundation.
For unstable soils consult your engineer for
a foundation design and have him do an inspection when the
foundations are cast.
(Have a look at the details section for
typical foundation details on the advice page of this site,
you might also want to read the article on concrete
construction in South Africa)
Waterproofing & floor slab casting
Residential ground floor slabs are usually
only one brick course thick (Apprx. 75mm) and are layed on a
well compacted crushed stone filling covered with riversand
and on a adequate damp proof membrance (The dpm is often
specified as a 250micron under surface bed layer). Make sure
that the layer of riversand in sufficient in thickness and
that it is well spread over the layer of crushed stone to
prevent penetrations through the sheet. Also check that the
final unfinished floor level is at least 2 brick cources
(170mm) above the natural ground level to prevent stormwater
or rising damp from entering the house and as required by
See to it that the builder is keeping the
floor slabs damp to ensure proper curing and that he has
ordered his building sand and cement from sound suppliers
who will supply him with the correct type of cement and
aggregate mix for slab casting.
When the slab is cast check your plans once
again to see that all conduits or pipes etc. are in place
for the sanitary fittings (wc, whb, shr, sink, etc.) and for
all the electrical fittings (plug outlets etc.)
Walls (Masonry work)
Before any bricks are laid check that the top
of foundation is square and level once again.
Make sure you get good quality stock/face
bricks from a sound supplier. When the bricks are delivered
to site inspect them and see if more than 5 out of 100 are
broken, if so the bricks might not be of optimum quality.
When using cement bricks/blocks make sure the
bricks are dry before being laid as shrinkage might occur
afterwards if they are laid wet which might result in mortar
jointing getting loose. concrete based the supplier must
supply a SABS certificate of compliance.
It is good practice to wet the bricks before
laying them as the dust accumulated on them might act as a
barrier between the mortar & the brick, also clay bricks
might absorb a lot of moisture out of the mortar mix which
it needs to cure (harden).
Before building of walls commences make sure
that your builder installs a layer of 250micron Plastic
sheet as wide as the wall as a damp proofing similar to the
sheet below the floorslab. Where there are platform
differences a vertical sheet should be installed to prevent
damp to the lower levels.
When the building is in progress, see that
the corner profiles (wooden masts with brick courses marked
of at the corners of the house) are plumb and that brickwork
is laid level as building proceeds. Make sure that the lines
spanned between profiles are always level and stretched
Bricks should be laid with brick-reinforcing
every third to 4th course, and every course above
door & window level.
Door & window frames should be built in and
see that they are at the correct placement and height and
that they are built in level. If you are building aluminium
window frames, openings will be left and the openings will
be measured on site and the windows built accordingly and
installed just before plastering commences.
Make sure that lintels are resting at least
150 mm on both sides of openings for openings smaller than
1,5m, or 250 mm for openings wider than that.
Bricks must be laid plumb and level, with
joints of about 10mm, properly filled.
With facebricks it is important that all
joints are properly filled, otherwise water will leak
through these joints into the interior skin of brickwork
Cavity walls (walls consisting of two brick
skins with small gap - 40-50mm usually) needs to be build at
all coastal residences with weep holes at the bottom for the
moisture to escape. It is also good practice to build cavity
walls at the western side of the building to eliminate the
heat created on the walls by the scorching western afternoon
Where cavity walls are built, wall ties are
to be used between the skins, at a rate of 4 ties per square
Roof design will depend on the type of
covering and the span over which the structure is built.
A timber sub-structured roof typically rests
on a wooden wallplate which acts as a ‘ringbeam’ around the
perimeter of the building to evenly distribute the loads to
the supporting walls.
The trusses & wall plate is anchored to the
walls with metal roof ties and needs to be built into the
wall at least 4 brick courses from the top.
The roof trusses should be graded and treated
and bear a mark of approval typically by the SABS. An
engineering certificate of compliance should be supplied to
you by the roof contractor.
The battens are the cross pieces of timber
spaced as per roofing material used. For tiled roofs they
are 38x38mm and spaced at appx. 330mm centres and 38x50 or
50x76 for sheetmetal coverings and spaced at 1,2 – 1,6m
apart depending on the manufacturer.
Brandering are similar to battens but is
nailed to the underside of the trusses for the ceiling to be
fixed to it. They are typically 38x38mm in profile and
spaced at 450mm centres. Make sure to have a trapdoor fitted
in between at a suitable place. (See also trapdoor detail –
at the details page of this website)
Depending on the roofing type and
manufacturer roof slopes may vary from 2 degrees to very
steep angles. Typically tiled roofs will not have a smaller
slope that about 17 degrees and will then require an
undertile waterproofing membrane (this is typically done for
roofs at a pitch greater than 45 or smaller than 26 degrees
and also prevents dust from entering and act against wind
loads that might be forced onto the roof),
Many sheetmetal profiles can be installed at
a very small slope without difficulty.
Where ever there is a protrusion through the
roof eg. A ventpipe, chimney shaft, parapet wall etc. these
areas should be properly flashed with galvanized sheetmetal
Depending on the style of architecture or
personal preference you might install a facia board and
gutter or not; however if you decide not to, it is good
practise and most local authorities will require you to
build an apron of 900MM min around the house perimeter to
prevent the falling water from corroding the earth around
the house and cause rising damp or structural failure of the
weakened brickwork by the moisture.
(For thatch roof information refer to the
article on thatch roof design on this website)
Construction of floors / Stairs
When constructing floors it can either be a
wooden floor raised and rest of wooden floor joists (beams)
and be concrete which is the preferred method because of its
better insulating qualities.
For concrete ground floors see also the
section regarding slab casting earlier. If you are building
a wooden floor, especially at higher levels consult a
qualified professional to work out the live loads which will
act out on the floor.
When considering which flooring material to
be used also consider the fact that a lot of services needs
to run in the floor and will need to be covered from below
is using wooden floor for the upper floors.
Local authorities in SA require stair treads
to be no less than 250mm and risers (vertical) to be no more
than 200mm. These however are minimums and a comfortable
stair should have at leas 270mm treads and 170mm risers. The
170mm risers also makes it easier if a concrete stair needs
to be built into a wall module as 170mm equals 2 brick
Other items and services
Plumbing & sewerage, electrical installation,
landscaping, Special fittings etc. will not be covered in
this document. Should you have any other questions please
contact us and we will do our utmost to provide you with