Planning a home renovation in London isn’t just about choosing paint colours or picking the right tiles. It’s about making smart decisions, avoiding delays, and staying in control — even when your schedule is packed.
Whether you’re considering a full refurbishment, a house extension in Finchley, or a flat renovation in Hampstead, this guide will walk you through how to plan a renovation that adds real, long-lasting value.
1. Know Why You’re Renovating
Before you start browsing Pinterest or calling architects, ask yourself:
- Are you running out of space?
- Wanting to improve energy efficiency?
- Preparing to sell in a few years?
- Dreaming of an open-plan kitchen?
Knowing your “why” sets your budget and priorities. For example, one of our recent clients in Muswell Hill wanted more light and space, but they also needed to stay put during the works. We planned the build in phases to minimise disruption and protect their daily routine.
2. Get Clear on the Budget (and Be Honest With Yourself)
A realistic budget isn’t just about the construction cost. You also need to factor in:
- Planning and design fees
- Building control applications
- Party wall agreements
- Temporary accommodation (if needed)
- Fixtures, fittings, and finishes
Tip: Add a 10-15% contingency fund for surprises — because even the best-laid plans can run into unforeseen issues.
3. Plan the Timeline — Not Just the Build Dates
Busy professionals often underestimate how long pre-construction can take. Here’s a rough timeline:
| Stage | Duration |
| Initial design + brief | 2–4 weeks |
| Planning permission | 8–12 weeks (if needed) |
| Detailed drawings + quotes | 2–3 weeks |
| Build phase (typical) | 8–20 weeks+ |
If you need your extension done before the school holidays or a newborn’s arrival, start early.
4. Choose the Right Builder — Not Just the Cheapest
This is where many renovations go wrong.
Look for a team who:
- Offers transparent pricing (no vague estimates)
- Has solid reviews from similar clients
- Communicates clearly and proactively
- Shows examples of work built to last
At Combit, we’ve taken over projects from cut-rate contractors who left clients with unsafe structures or half-finished jobs. Fixing mistakes always costs more than doing it right the first time.
5. Design With Function First
You might love the look of a steel-and-glass loft — but is it warm in winter? Is there enough built-in storage? Will it work for your lifestyle 5 or 10 years from now?
Ask your builder and designer:
- How will this layout feel day-to-day?
- What maintenance will it need?
- Are there ways to make it more energy-efficient?
Future-proofing your renovation makes it a better long-term investment.
6. Avoid These Common Renovation Mistakes
- Skipping planning permission checks: Especially for lofts or side extensions in conservation areas.
- Not agreeing on detailed specs up front: Vague scopes = ballooning costs.
- Choosing style over substance: Cheap fittings wear out fast.
- Assuming you can “live through it”: Renovation dust and noise are no joke.
Renovation Planning Checklist
Before you start, make sure you:
- Define your goals and lifestyle needs
- Set a clear, itemised budget
- Choose reputable builders with proven work
- Understand planning and legal requirements
- Have a realistic, phased timeline
- Build in contingency funds
- Ask questions until you’re confident
Ready to Start?
Use our Project Cost Calculator to get a ballpark figure in minutes. It’s the first step to planning with confidence — no obligation, just clarity.