The right choice depends on the existing building, the opportunities of the site and the life you want from it. Comparing those factors together is more useful than deciding solely on the age or appearance of the house.
Identify what already works
Begin with the home's strengths: a good orientation, generous rooms, a mature garden, character details or a useful relationship to the street. Retaining those qualities may be central to the project. A house that looks dated can still have a strong spatial structure.
Then distinguish cosmetic problems from fundamental ones. Finishes can be changed relatively simply; poor room relationships, difficult level changes and an awkward position on the site may require more substantial intervention. Record the problems before committing to a solution.
Understand the building before promising a plan
Existing drawings rarely tell the complete story. Dimensions, structure, condition and services need to be understood at a level appropriate to the proposed work. Relevant specialists may need to investigate issues before the scope and cost can be defined with confidence.
An extension also needs to connect well to the home that remains. Think about circulation, daylight and roof relationships, as well as the extra floor area. More space is useful only if it improves how the whole house works.
Compare options on the same basis
A renovation estimate and a new-build estimate can be misleading if they include different work. Set out the intended rooms, quality of finishes, outdoor works, services and professional inputs for each option. Include demolition or removal where relevant, and be clear about what remains uncertain.
Ask which assumptions have the greatest influence on each estimate. An early comparison should explain its limitations. A single headline figure is a poor substitute for a clear scope and a realistic allowance for unresolved matters.
Include the disruption to daily life
Consider temporary accommodation, access, storage and the effect of building work on the household. Staying in a house during work is not always practical or appropriate. The likely staging and safety requirements should be discussed with the project team before relying on that option.
Timing also needs to account for assessment, design, approvals, documentation and procurement. Avoid judging an option only by the time spent physically building it. Each project has a different critical path.
Make the decision with a site-specific comparison
A useful first-stage outcome is a short comparison of the viable options, their benefits, constraints and outstanding questions. The relevant planning controls, heritage considerations and approval pathway need to be checked for the actual property with suitable advice.
The best direction may be less dramatic than expected: a carefully planned alteration, a targeted addition or a new home that uses the site differently. The aim is a coherent result that supports your priorities and resources.
- What qualities would be lost if the existing home were removed?
- Can the most important daily-life problems be solved within the building?
- Which site or building questions remain unverified?
- Are the options being compared with equivalent inclusions?
- What level of disruption can the household accommodate?
Bring this into your project.
A site and brief discussion can identify the information needed before you choose between renovation, extension and rebuilding.