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Get an estimate for quoting your clients for design costs. Calculate how much to quote for design fees.

Estimating building projects can be a complex process because final costs depend on many varying factors. It is important to manage your expectations with the knowledge that you will only get an accurate idea of the price for your project when drawings and schedules of work are complete. These drawings outline your particular requirements, the type of house construction and any other factors specific to your project. The cost process evolves and cost certainty only comes from full design certainty.

Early stage project cost calculator

Our simple early stage cost calculator is intended as a starting point for your inevitable initial project research. Use it before you have drawings or pricing schedules to give you that initial ball park figure of how much your project might cost. Please remember these are guideline costs only. They do not include VAT, contingency costs and professional fees (like planning fees). Talk to us about our Kickstart Consultation for a more accurate early stage costs analysis from a professional architect.

In addition to the cost calculator, you can read our guide to estimating building costs for domestic projects.


Step 1
Break down your ideas into different zones of work, for example:

  • New build
  • Renovation

Calculate the area of each zone in m2 and enter in the appropriate box. Leave the boxes blank for zones in which you are not carrying out work in.

Step 2
Decide whether you require a basic spec or high spec. Set the ‘options’ slider to the middle for a basic spec and and far right for high spec.

Step 3
Make an assessment on how technically complex your project is. Basements, curves, old buildings, building access difficulties and building on slopes are all examples of things that add complexity and therefore higher costs to projects. Set the ‘complexity slider’ (which is number 0-10) to how reflect how complex you feel your project is going to be.


New build

This refers to the area of new build extension on each floor. If you want a two storey extension include both the new areas on each floor.

Total Estimated Cost (฿)

More information

If you'd like advice or to discuss this estimate email below