The Hidden Costs of Renovation: What to Watch Out for in High-End Projects

Mayfair Construction
May 28
3 min read

Luxury renovations are as rewarding as they are complex. Whether you're refurbishing a period townhouse in Mayfair or transforming a newly purchased property into a forever home, hidden costs can catch even the most prepared homeowners off guard. At Mayfair Construction, we believe transparency is key. Here's what to look out for to protect your budget - and your peace of mind.

1. Planning & Professional Fees

Many clients focus on construction costs and overlook the significant outlay required upfront for design and compliance:

Architects and interior designers
Structural and M&E engineers
Planning consultants (especially if you're in a conservation area or listed property)
Building control, party wall surveyors, and planning application fees

Tip: Budget an additional 10–15% of total project cost for professional fees.

2. Survey Surprises and Structural Issues

Older Mayfair properties often hold unexpected secrets behind the plasterwork - woodworm, dry rot, movement cracks, or outdated foundations.

Timber decay or structural instability
Hidden damp, asbestos, or corroded pipework
Legacy alterations not done to building regs

Tip: Commission a full building survey before committing to your scope. And build in a contingency.

3. Material Lead Times & Shortages

Global supply chains remain volatile, and specialist materials - like bespoke joinery, imported stone, or brassware - can delay projects and increase holding costs.

Extended lead times often lead to rushed decisions or compromises
Overnight price increases can derail budgets mid-build

Tip: Confirm availability before finalising your spec. At Mayfair Construction, we always offer comparable alternatives in case of delays.

4. Access, Logistics & Neighbour Considerations

Mayfair isn’t known for its easy site access. Tight streets, restricted parking, and shared party walls can all add hidden logistical costs.

Skip permits, scaffold licenses, out-of-hours working restrictions
Deliveries needing handballing due to lack of crane access
Additional security or hoarding in high-footfall areas

Tip: We conduct detailed site assessments to identify access costs early and avoid surprises.

5. Client-Initiated Changes (Variations)

Every project evolves - but when changes are made mid-build, they often come with cost and time implications:

Design changes after construction has begun
Late spec decisions or upgrades
Delays waiting on client approval

Tip: Lock in as many design decisions as possible before site start. Variations add up quickly, especially on high-spec work.

6. Temporary Works & Enabling Packages

Before the glamorous finishes come the gritty prep work:

Propping, underpinning, and temporary waterproofing
Protection of retained elements like original staircases or floors
Utility disconnections, diversions, and service upgrades

Tip: These packages aren’t exciting, but they’re essential. We always include them clearly in our cost plans so you're not caught off guard.

7. Snagging & Defect Rectification

Even the best projects require some post-completion snagging. High-end work demands perfection, and the final 5% can take 20% of the effort.

Minor paint touch-ups, hardware adjustments, or re-polishing
Replacing items damaged during final cleaning or furnishing
Delays caused by waiting for final client inspections

Tip: Include a small post-completion budget to cover finishing touches without stress.

Final Thoughts: Prepare Smart, Avoid Surprises

A luxury renovation is a significant financial and emotional investment. Knowing where hidden costs can appear allows you to plan effectively and work with your contractor to avoid nasty surprises. At Mayfair Construction, we pride ourselves on transparent pricing, proactive risk management, and honest conversations from day one.

Planning a renovation in 2025? Let us help you build beautifully and confidently, with no hidden costs in the shadows.

Mayfair Construction Developments Limited

Unit 1 Petham Court Farm, BR8 8DLCompany

Reg No.: 07048199