Building Plans for Additions & Alterations

Building Plans for Additions & Alterations are required for any construction on your existing structure.

Copy of existing building plans, together with plans showing the proposed additions and alterations are required when applying for approval.

Sometimes people only discover that there are no plans years after they have bought a property.

Other times people find at the point of sale that a house they are buying does not have plans.

Whose is responsibility to have plans drawn up retrospectively? The current Owner is responsible for the records of their dwelling.


If changes have been done without Council approval and the property subsequently sold, it may result in a legal action.

A lack of approved Building Plans for Additions & Alterations will cause complications when buying and selling developed properties.

I would like to do additions and alterations to my existing dwelling,

how do I get plans for it?

Copy of existing plans

Before embarking on additions and / or alterations, a site analysis needs to be undertaken by the Architect or Draughtsman.

When doing a site analysis, several factors need to be investigated before the drawing process even begins.

The first step is for the client to obtain a copy of their Title Deeds.

They can be obtained from the bank which or from a registered Estate Agents, having access to the Deeds Office.

The reason for the Title Deeds, is to confirm Restrictive clauses.

A zoning certificates, indicating which town planning scheme the property is subject to and any Restrictive clauses.

Zoning certificates will indicate:


A SG diagram (aka Surveyor General diagram) showing:

  • Roads and their names.
  • Neighbouring stands, stand numbers.
  • Boundary lengths and stand orientation relative to North.
  • Sewer servitude or any other servitude that affect the property.

Copies of the existing approved structures plans.

Most local authorities have archived microfiche copies of these plans and related documentation when the file was first opened.

However microfiche copies are usually of such poor quality, that at times copies of these plans are illegible.

In this case, the Architect or Draughtsman may have to measurement on-site in order to confirm the structures size.

Prior to starting any sketch plans, the Architect or Draughtsman will then analyse the data together with the client’s brief.

Stage 1 Sketch plans [ Concept plans]
Stage 2 & 3 Final design
Stage 2 & 3 Final design
tage 4.2 Working drawings
Stage 4.2 Working drawings

STAGE 1 – Sketch plans:

After the site analysis, the Owner has been informed if the proposed additions and/or alterations will be supported by Council.

If all is in order, the Owner instructs the Architect or Draughtsman to proceed with STAGE 1 (sketch plans)

Owners must scrutinize the sketch plans to verify that they are happy with the room sizes.

We change the sketch plans requested by the Owner, to facilitate a smooth transition to STAGES 2 & 3.

STAGE 2 & 3 – Final design

At this stage the Owner has accepted the sizes and position of the proposed addition and/or alterations.

During STAGE 2 & 3 we extruded a 3-D model, so the Owner may visualize the scale of the project.

Showing proposed changes in relationship to the existing structure.

STAGE 4.2 – Working drawings

Once the Owner is satisfied with STAGE 2 & 3, they then sign off the Final design.

STAGE 4.2 Construction plans and related documentation for the local authority is prepared.

Plans and related documentation must comply with the  National Building Regulations and SANS 10400 regulations.

How can a virtual 3-D model of my proposed additions and alterations help me?


We use 3-D models extensively during the designing process.

It aids the Architect and Draughtsman to visualize the aesthetic of a building.

To line up windows and doors and checking for drainage pipes visible or passing in front of a window.

Not all people have been taught how to correctly read a 2-D paper plan.

Owners are able to see their proposed additions and/or alterations in a scale which they can interpret.

To add the visual experience, we populate 3-D models with items e.g furniture, kitchen units, light fittings and sanitary fittings.

When an Owner sees a fully equipped kitchen in the model space it is easier for them to make changes.

In the past models would have to be built to show a prospective Owner’s new dwelling, office building or factory.

Models took weeks to complete and when changes needed to be made a new model would have to be constructed.

With improved technology and superior software we are now able to design any structure in a 3-D model space and effect changes immediately, the benefits are saving in time and money.

We do not rest are just producing 3-D models, we render our models to present a more photo realistic visual representation which we have found helps Developers and Estate Agents with the advertising and marketing materials.

Clients are also able to edit specific features of their structures, for example playing with colours and textures, rock-face cladding or face brick. We are also able to show our clients various roofing options for the same design floor plan, and landscaping options.

3-D models enrich a client’s experience of the drawing process, and they all feel more involved in the decision-making process. This is a tool with great benefits which are clearly obvious to both the designer and client.


What are the benefits on having detailed drawings?

Having detailed drawings, is necessary for Quantity Surveyors when determining a cost estimate and bill of resources.

Sometimes the lack of details on a plan lead to a number of misunderstandings between Owner and contractors.

Here is a list of some misunderstandings and unrealistic expectations we have come across over the years:

  • The Contractor will work it out, it’s their job


– Simply put builders only want to build and not work out possible design flaws.

Contractors prefer when decisions have been made and documented so that they don’t have to chase your Architect for decisions.

Thus Crane Designs ensures your contractor is given the correct information and expectations.


  • Contractors don’t want Architectural or Draftsman’s on the job site.


– However, some contractors that we have worked with are glad to consult with us, it’s a collaborative effort.

Contractors prefer someone to help guide them so that mistakes are less frequent and communications is effective.


  • They should be able to figure it out from the drawings


– Drawings are interpretive and they often need confirmation from either the Architectural or Owner, to make sure they are understood.


  • The Contractors know what will meet code 


– Most builders don’t have the time to keep up with the details of the codes the way an Architect must.

Furthermore, it is the Architect who is the registered professional.


  • The client is paying twice if the Architect and Contractor are both there


– The Architect is the designer; the Contractor is the builder. There is no overlap, just coordination and collaboration.


  • Contractors always read the drawings


– Good, experienced Contractors study the drawings, the way in which each Contractor reads drawings may vary.

Some details are frequently overlooked at the early phases.


  • The subcontractors read the drawings 


– In residential and small commercial projects, many subcontractors never see the drawings. All the Contractors should be reviewing the drawings.


  • The Owner can build this on their own and be their own Contractor


– Unless the home Owner has construction experience, it’s not advised to attempt the project on your own.


One key note to remember is to not fire a team member of the Contractor’s midway through the project.
This is truly not the way to save money or time. Tell your Architect what the budget is and pay them to work with you and your Contractors.