Budgeting for a Renovation or New Build: What Clients Often Forget

The Budget Trap

When clients first approach us, they often come with a ballpark figure in mind—usually based on build cost alone. But successful projects depend on understanding the full picture of expenses, not just what the builder quotes.

At Karenna Wilford Architects, we help clients budget with clarity from day one, so expectations match reality and their investment delivers long-term value.

Close-up of a person in a blue shirt stacking coins into neat piles, symbolising careful financial planning for a home renovation or build.

Professional Fees Beyond Construction

Detailed architectural plans in a consultation

Many homeowners forget to include the full team in their financial planning. A well-run project typically involves:

• Architect fees (design, drawings, planning, tendering, contract admin)

• Structural engineer fees

• Planning consultant (if needed)

• Building control and specialist surveys

  
  

These services ensure your build meets regulations, performs well and looks beautiful—but they must be accounted for.

Planning Application Costs

Completed planning application forms.

Even simple home improvements often require planning permission. This involves:

• Local authority planning application fees

• Pre-application advice (optional, but helpful)

• Additional design iterations and supporting documents

  
  

Don’t forget that listed buildings, conservation areas or greenbelt locations can require more submissions—and time.

Surveys and Site Investigations

Site survey in progress.

Before construction begins, certain surveys may be necessary:

• Topographical survey

• Measured building survey (for renovations)

• Soil investigations or tree reports

• Ecology or heritage assessments (in sensitive areas)

  
  

These protect you from expensive surprises later and support smooth planning approval.

VAT and Legal Considerations

Many clients overlook VAT entirely in their costings:

• Most renovations and extensions incur 20% VAT

• New builds may qualify for zero-rated VAT—but only under strict criteria

• You may also need to budget for:

  • Party wall agreements

  • Land registry or legal fees

  • Insurance during construction

We advise early on all relevant tax implications and planning conditions.

Contingency Planning

Envelope labelled “Contingency Plan”.

A well-managed project still needs a financial buffer. We typically recommend:

• 10–15% contingency for unexpected costs (especially in older properties)

• Examples include hidden structural issues, utility upgrades or supplier delays

This contingency should sit outside your "core" budget and only be dipped into if absolutely necessary.

Interim Payments and Cashflow

Site in progress with scaffolding.

Builders are usually paid in stages throughout the build—called interim valuations. These must be:

• Agreed in advance (your architect can help negotiate terms)

• Planned around your own finances or lender drawdowns

• Supported by progress inspections and payment certificates

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Poor cashflow planning can delay work or lead to rushed decisions.

Budget With Confidence, Not Guesswork

Budgeting for a renovation or new build is more than maths—it's about risk management, planning foresight and strategic investment. By thinking beyond bricks and mortar, you give your project the best chance of success.

At Karenna Wilford Architects, we guide clients through the financial realities of design and construction. The result? Homes that are not only beautiful but delivered without budgetary shock.

Need help planning your renovation or new home build? Get in touch with our team to start your journey with transparency and confidence.