Build or Buy

This has the potential to be a big project involving mortgage finance, interest rates, income tax, national insurance, scheduling, Gantt diagrams and estimation. Alternatively the task could be split into smaller stand-alone chunks.

The task starts with considering the financial implications of having a mortgage and the associated bills of owning a house. A lot of relevant financial information is provided. (Note: this will be liable to change each financial year, so will need to be updated regularly.) The task then considers the alternative option of building your own house. This introduces scheduling issues and activity networks, before considering the estimation of the costs involved.

Mathematical Strands

Number and Measures, Financial Maths, Discrete Maths

Prior knowledge

The task could provide revealing insights into the costs of owning a house.

Relevance to Core Maths qualifications

  • AQA
  • C&G
  • Eduqas
  • Pearson/ Edexcel
  • OCR

Suggested approaches

Ideal for group work with plenty of opportunity for collaboration and discussion. The three case studies lend themselves to three groups.


In addition to these teacher notes/guidance there are:

  • Extensive teacher notes within the PowerPoint.
  • An Excel spreadsheet with the solution to the scheduling problem
  • Link to website for mortgage budget planner – within PowerPoint slides
  • A six-question assessment: House assessment

Relevant digital technologies

Spreadsheets to: compare the mortgage offers; complete scheduling activities.

Possible extensions

There is plenty of scope to tailor this activity within a scenario to suit your students. A new build at school/college?


Developed by Nicola Letts at The Duston School.